vi international symposium on radiation physics - Universidad ...

VI INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS 

March 7-10, 2010, Zacatecas, Zac. Mexico 

Directive Board DFR-SMF 

Guillermo Espinosa, President 

Efrain Chavez, Vicepresident 

Julio Herrera, Secretary 

Horacio Martinez, Treasurer 

International Ad<strong>vi</strong>sory Committee 

Technical support 

Arcadio Huerta 

Jose Ignacio Golzarri 

A Frank ICN UNAM, Mexico 

D. Shapira Oak Ridge Natl. Lab., USA 

J. Lopez U. Texas at el Paso, USA 

F.D. McDaniel U. North Texas, USA 

B. Doyle Sandia Natl. Lab., USA 

L. Sajo Bohus U. Simon Bolivar, Venezuela 

Organizing Committee 

Guillermo Espinosa 

Efrain Chavez 

Hector Rene Vega-Carrillo 

Alejandro Frank H. 

Local Committee 

Consuelo Letechipia de Leon 

Victor Martin Hernandez-Da<strong>vi</strong>la 

Miguel Angel Salas-Luevano 

Eduardo Manzanares-Acuna 

http://www.smf.mx/~fr-smf 

i

VI INTERNATIONAL SYMPOSIUM 

ON 

RADIATION PHYSICS 

BOOK OF ABSTRACTS 

Universidad Autónoma de Zacatecas 

March 7th - 10th, 2010 

ii


ON 



March 7-10, 2010 

Radiation Physics Di<strong>vi</strong>sion 

Sociedad Mexicana de Física 

Directive 

Committees 

Guillermo Espinosa, President. 

Efraín Chavez, Vice-president. 

Julio Herrera, Secretary. 

Horacio Martinez, Treasure. 

- Organizing Committee 

Guillermo Espinosa espinosa@fisica.unam.mx 

Efraín Chávez chavez@fisica.unam.mx 

Héctor R Vega Carrillo fermineutron@yahoo.com 

Alejandro Frank frank@nucleares.unam.mx 

- International Ad<strong>vi</strong>sory Committee 

Alejandro Frank, Instituto de Ciencias Nucleares-UNAM, México. 

Dan Shapira, Oak Ridge National Laboratory, USA. 

Jorge Lopez, University of Texas at El Paso, USA. 

Floyd McDaniel, University of North Texas, Denton USA. 

Laszlo Sajo-Bohus, Universidad Simon Bolivar, Venezuela. 

- Technical Support 

José Ignacio Golzarri 

Arcadio Huerta 

Correspondence 

Dr. Guillermo Espinosa. 

golzarri@fisica.unam.mx 

arcadio@fisica.unam.mx 

espinosa@fisica.unam.mx 

iii


ON 


Sponsors: 


Consejo Nacional de Ciencia y Tecnología 

Sociedad Mexicana de Física 

Centro Latinoamericano de Física 


March 7th - 10th, 2010 

iv


March 8 th to March 10 th , 2010 

PROGRAM 

Monday, 8 th March 

8:00 - 9:00 Registration 

9:00 - 9:30 Inauguration 

9:30 - 10:10 Plenary Talk (P-1) 

Alejandro Frank 

Chair: G. Espinosa 

10:10 - 10:50 Plenary Talk (P-2) 

V.V. Nes<strong>vi</strong>zhevsky 

Chair: G. Espinosa 

10:50 - 11:10 Coffee Break. 

11:10 - 12:50 In<strong>vi</strong>ted Talks (O-1 a O-4) 

Chair: M.E. Ortiz Salazar 

12:50 - 13:30 Round Table: Poster presentation (1-14) 

Chair: L. Sajo-Bohus / G. Espinosa 

13:30 - 15:00 Lunch 

15:00 - 15:40 Plenary Talk (P-3) 

Michael Snow 

Chair: E. Chavez Lomelí 


Chair: E. Chavez Lomelí 

16:55 - 19:00 Coffee Brake and Poster Session (1) 

Chair: M.E. Ortiz Salazar / E. Chávez Lomelí 

v

Tuesday 9 th March 

8:00 - 8:40 Plenary talk (P-4) 

Jorge Rickards 

Chair: H. Vega Carrillo 

8:40 - 9:55 In<strong>vi</strong>ted Talks (O-8 aO-10) 

Chair: H. Vega Carrillo 

9:55 - 10:15 Coffee Break 


Chair: H. Vega-Carrillo 

11:30 - 12:20 Round Table: Poster presentation (15-28) 

Chair: J. López / C. Vázquez López . 

12 :20 - 13 :00 Coffee Brake and Poster Session (2) 

Chair: A. Varela / C.Vázquez López 

14:00 - 16:00 Meeting Lunch (Official lunch) 

19:00 - 22:00 Zacatecas Callejoneada (Walking start with music) 

Wednesday 10 th March 

8:30 - 9:10 Plenary Talk (P-5) 

L. Sajo-Bohus 

Chair: J. Herrera Velazquez 


Chair: J. Herrera Velazquez 

10:00 - 10:20 Coffee Break 


Chair: J. Rickards / J. López 

12:00 - 13:00 Round Table: “Sociedades de Física de Radiaciones Ionizantes” 

Dr. Juan Azorín (SMID), Dr. Guillermo Espinosa (DFR-SMF), 

Fís. Víctor Tovar (SMSR) 

Chair: E. Chávez Lomelí 

13:00 - 13:30 General Conclusions and Closing 

13:30 - 14:30 General assembly: Radiation Physics Di<strong>vi</strong>sion of the SMF 

<strong>vi</strong>


PROGRAM 

Monday March 8 th , 2010 

8:00 - 9:00 Registration at the Main Building (Rectoría) of the Universidad Autónoma de Zacatecas 

9:00 - 9:30 Inauguration at the “Rectoria” of the Universidad Autonoma de Zacatecas 

9:30 - 10:10 40 

P-1 Plenary talk 

Advances in Nuclear Physics 

Alejandro Frank 

10:10 - 10:50 40 P-2 Plenary talk 


10:50 - 11:10 20 Coffee Break 

25 

In<strong>vi</strong>ted Talk 

11:10 - 11:35 O-1 

Libertad Barrón 

25 

O-2 In<strong>vi</strong>ted Talk 

11:35 - 12:00 

12:00 - 12:25 

25 


12:25 - 12:50 25 O-4 In<strong>vi</strong>ted Talk 

12:50 - 13:30 40 

90 

13:30 - 15:00 

Dan Shapira 

Julio Herrera 

Efraín Chavez 

1-15 Round Table. Poster description-1 

Lunch 

Powder of diamond nanoparticles as the 

best reflector for slow neutrons. 

Fundamental neutron physics in Mexico 

Extending studies of the fusion of heavy 

nuclei to neutron rich region using 

accelerated radioactive ion beams 

Fusion de<strong>vi</strong>ces as plasma based 

neutron sources 

Study of 15 N By 14 C(p,p) 14 C using 

polarized proton beam 

40 

Plenary Talk 

15:00 - 15:40 

P-3 

25 


15:40 - 16:05 


25 O-7 In<strong>vi</strong>ted Talk 

16:30 - 16:55 

16:55 - 19:00 1h 

All 

W. Michael Snow 

Jaime A. Fernandez Baca 

L. Paredes - Gutierrez 

Ernesto Belmont 

Coffee Break and POSTER SESSION (I) 

Nuclear/Particle/Astrophysics with slow 

neutrons 

Neutron scattering studies of the 

magnetic interactions in the 

geometrically frustrated triangular lattice 

antiferromagnet CuFeO 2 

Radiological accident: fast neutrons 

absorbed dose estimation using hair 

HAWC, a new high energy gamma 

detector in Mexico 

1


PROGRAM 

Tuesday March 9 th , 2010 

8:00 - 8:40 40 P-4 Plenary talk 

The production of optical waveguides by 

Jorge Rickards 

ion implantation: the case of rutile 


Central for irradiation of materials of 

8:40 - 9:05 

D. Ila 

Alabama A&M University 


9:05 - 9:30 

L. Tavera Uses of Radiation Damage in Insulators 

25 

Thermoluminescent detectors for 


neutron ambient dose equivalent H*(10) 

9:30 - 9:55 

Teodoro Rivera 

determination 

9:55 - 10:15 20 Coffee Break 

25 

Electron dynamics of transition metal 


compounds studied with resonant soft x- 

10:15 - 10:40 

José Jimenez-Mier 

ray scattering 

10:40 - 11:05 25 

O-12 In<strong>vi</strong>ted Talk Jorge Lopez XRF analysis of obsidian 

11:05 - 11:30 

25 


D.C. Burciaga 

Synchrotron radiation study of the 

uranium chemical species 

electrodeposited for alpha spectrometry 

sources 

11:30 - 12:20 50 

16-30 Round Table. Poster description-2 

12:20 - 13:00 40 Coffee Break and POSTER SESSION (II) 

14:00 - 16:00 2h Meeting Lunch (Official lunch) 

16:00 - 19:00 3h Free time 

19:00 - 22:00 3h Zacatecas “Callejoneada” (Walking start with music) 

8:30 - 9:10 

9:10 - 9:35 

40 

25 

25 

9:35 - 10:00 

10:00 - 10:20 20 

P-5 

Plenary talk 

Wednesday March 10 th , 2010 

Laszlo Sajo-Bohus 

O-14 In<strong>vi</strong>ted Talk Juan Azorín Nieto 



10:20 - 10:45 


25 

11:10 - 11:35 

11:35 - 12:00 25 

12:00 - 13:00 60 

O-18 

In<strong>vi</strong>ted Talk 

M.A. Martinez-Carrillo 

Carlos Vazquez 

Carlos Chapa 

Arturo Angeles 

Coffee Break 

Analysis and correction of track 

overlapping on nuclear track detectors 

(SSNTD) 

Determination of neutron dose in 

medical LINAC 

Bioaccumulation of chemical elements in 

Tillandsia usneoides L. at the industrial 

zone of Tula, in Central Mexico 

Improvement to nuclear track counting 

systems by laser light scattering 

Photomultiplier principles & application 

for thermal and fast neutron detection. 

The detailed deposited energy in lung 

cancer tissue from radon’s daughters 

calculated by a Montecarlo code 

O-19 In<strong>vi</strong>ted Talk H.R. Vega-Carrillo ANN and Neutrons 

Round Table: “Sociedades de Física de Radiaciones Ionizantes” 

Participants: Dr. Juan Azorín (SMID), Dr. Guillermo Espinosa (DFR-SMF), Fís. Víctor Tovar 

(SMSR) 

Chairr: Dr. Efraín Chávez 

13:00 - 13:30 30 General conclusions and Closing 

13:30 - 14:30 60 General assembly: Radiation Physics Di<strong>vi</strong>sion of the SMF 

2


PROGRAM 

March 8 th -10 th , 2010 

POSTERS 

1 Maritza R. Gual Absorbed dose by a biological sample 

located at a Nuclear Reactor Beam Port 

2 Luis Hernández-Adame 18 MV Linear Accelerator Bunker 

3 Roberto Mendez-Villafañe 

241 Am-Be source term simulation with Monte Carlo methods 

4 J.M. Ortiz-Rodríguez Comparing the Neutron spectra unfolding features using two codes 

5 Luis Sinhue Gaytan Multichannel Analyzer in Field Programmable Gate Array 

6 Carlos Hernandez-Villasana Shielding features of Quarry Stone 

7 Edmundo Escareño-Juarez Measuring 40 K to estimate total K concentration 

8 Héctor Contreras-Sandoval Validity of Special Relati<strong>vi</strong>ty Theory using the Compton Scattering 

9 Carlos Alberto Mares-Esparza Nitrogen determination with prompt gamma neutron activation 

10 Antonio Baltazar-Raigoza Changes in the neutron spectra inside an 18 MV LINAC treatment 

11 Rogelio Gonzalez-Gonzalez Dose in eyes, thyroid and gonads during chest x-ray radiography 

12 José Alberto Guerra-Moreno Dosimetry in the Radiology Department at the HGF 

13 José Manuel Ortiz-Rodriguez Performance of Artificial Neural Networks and Genetical 

Evolved Artificial Neural Networks unfolding techniques 

14 José Manuel Ortiz-Rodriguez Neutron Spectrometry using Artificial Neural Networks 

for a Bonner Sphere Spectrometer with a 3 He Detector 

15 José Manuel Ortiz-Rodriguez User-friendly interface to run the Monte Carlo 

Neutral Particle code for radiation physics 

16 Manuel A. Pulido-Gaytan Design and construction of a Multichannel Analyzer 

17 A. Gallegos Thermo-transferred Thermoluminescence in potassium-yttrium and 

potassium-lutetium double fluorides doped with terbium 

18 Guillermo Espinosa A study and characterization of the optically stimulated 

luminescence response of commercial SiO 2 optical fiber to gamma 

radiation 

19 Faustino Juarez Radon concentration levels in 16th century’s churches and 

convents. Sn Sebastian Church at Municipio La Paz Mexico State 

20 Jorge Rickards Long term indoor radon measurements in the Pelletron 

laboratories at the UNAM Physics Institute 

21 Alberto Barragan-Vidal Structural modification of Al surfaces suing high energy proton 

radiation 

22 Ja<strong>vi</strong>er Miranda Preliminary results in the development of a versatile spectrometer 

for X-ray fluorescence 

23 Fermin Castillo Neutron characterization at the FN-II Dense Plasma Focus 

24 J.N. Martinez The production of 3 H and 11 C radioactive beams at ININ Tandem 

accelerator 

25 Armando Varela The detection of cosmic neutrons using an extended range Bonner 

spectrometer 

26 Epifanio Cruz-Zaragoza Radiation response of polyminerals fraction from Hibiscus 

sabdariffa L foodstuffs 

27 B.C. Ruiz Gamma radiation effects in commercial Coriandrum sativum L for 

consumption in Mexico 

28 María Elena Montero Baccharis Salicifolia as a revealer of uranium contamination in arid 

en<strong>vi</strong>ronments analogous to San Marcos, Chihuahua. 

30 Jorge Luis Benites Renfigo Neutron spectra in a linear accelerator for radiotherapy 

3

PLENARY TALKS 

| 

4

Advances in Nuclear Physics 

Dr. Alejandro Frank 

Instituto de Ciencias Nucleares 

Universidad Nacional Autónoma de México 

frank@nucleares.unam.mx 

5

Powder of diamond nanoparticles as the best reflector for slow neutrons 


Institut Laue-Lange<strong>vi</strong>n, 6 rue Jules Horowitz, Grenoble, France, F-38042, 

nes<strong>vi</strong>zhevsky@ill.eu 

Diamond, with its exceptionally high optical nuclear potential and low absorption crosssection, is a 

unique material for a series of applications related to very cold neutrons (VCN). In particular, powders 

of detonation diamond nanoparticles (1), (2), (3) pro<strong>vi</strong>de the best reflectors for neutrons in the complete 

VCN energy range (4), (5), thus bridging the gap between efficient reactor reflectors (6) for thermal 

and cold neutrons and optical neutron-matter potential (7) for UCN (see Fig. 1). The nanoparticle 

characteristic size of ~5nm is close to VCN wavelength. Such a nanoparticle consists of a diamond 

nucleus (with a typical diamond density and optical nuclear potential) within an onion-like shell of a 

complex chemical composition (with significantly lower optical potential). Such a powder allowed also 

the first observation of quasi-specular reflection of cold neutrons (CN) from disordered medium (8). 

Effective critical velocity for such a quasi-specular reflection is higher than that for the best supermirror. 

Nano-diamonds sur<strong>vi</strong>ve in high radiation fluxes; therefore they could be used in <strong>vi</strong>cinity of 

intense neutron sources, where other solutions are ruled out. In the energy range of ultracold neutrons 

(UCN), diamond nanoparticles triggered unique investigations of thermal motions of 

nanoparticles/nanostructures on surface. 

Fig. 1. The elastic reflection probability for isotropic neutron flux is shown as a function of the neutron 

velocity for various carbon-based reflectors: (1) Diamond-like coating (DLC) (thin solid line), (2) The 

best supermirror (9) (dashed line), (3) Hydrogen-free ultradiamond powder with the infinite thickness 

(dotted line). Calculation. (4) VCN reflection from 3cm thick diamond nano-powder at ambient 

temperature (point), with significant hydrogen contamination (5). Experiment. (5) MCNP calculation 

for reactor graphite reflector (6) with the infinite thickness at ambient temperature (neutron energy 

should not increase). 

1. de Carli, P.J., and Jameieson, J.C. Science. 1961, 133, 1821. 

2. Aleksenskii, A.E. et al. Physics of Solid State. 1999, 41, 668. 

3. Dolmatov, V.Yu. Russ. Chem. Rev. 2007, 76, 339. 

4. Nes<strong>vi</strong>zhevsky, V.V. et al. NIM A. 2008, 595(3), 631. 

5. Lychagin, E.V. et al. Phys. Lett. B. 2009, 679, 186. 

6. Fermi, E. A Course in Neutron Physics. Chicago : The University of Chicago Press, 1965. 

7. Fermi, E. et al. Phys. Rev. 1947, 71, 666. 

8. Cubitt, R. et al. Phys. Rev. Lett. 2009, submitted. 

6

Nuclear/Particle/Astrophysics with Slow Neutrons 

W. Michael Snow 

Indiana University. 

Precision experiments using slow neutrons can be used to address many interesting questions in 

physics. In this area of research, slower is better. I will explain the technology used to slow neutrons 

down and describe a few examples of experiments which address important unsolved questions in 

nuclear, particle, and astrophysics. 

8

The production of optical waveguides by ion implantation: the case of rutile 

J. Rickards, R. Trejo-Luna, E. Flores-Romero, J.I. Golzarri y G. Espinosa 

Instituto de Física, UNAM 

Ap. Postal 20-364 

México, D.F. 

With the purpose of developing optoelectronic de<strong>vi</strong>ces, optical waveguides have been produced by ion 

implantation in many solids. The implantation process creates a damaged layer near the end of the ion 

trajectories, with a consequent reduction of density and index of refraction. This produces an optical 

barrier at a depth of a few microns, depending on the type of ion and its energy. The barrier and the 

surface constitute a planar waveguide. Rutile (TiO 2 tetragonal structure) single crystals were implanted 

with 7 MeV carbon ions using the Instituto de Física 3 MV Pelletron Accelerator, in the 100 and 001 

directions. The waveguides were observed using the coupled prism technique, which indicated 

differences in the waveguides produced for different directions due to crystal anisotropy. 

We are gratefully to DGAPA-UNAM for support the project 1N101910-PAPIIT 

9

Analysis and correction of track overlapping on nuclear track detectors (SSNTD) 

Daniel Palacios, Laszlo Sajo-Bohus, Haydn Barros, 

Eduardo Graves, Emidio Fusella 1 , Juan Sojo, Yininber A<strong>vi</strong>la 

Universidad Simón Bolívar, Caracas, Venezuela 

1 Instituto de Estudios Avanzados (IDEA), 

Caracas, Venezuela 

Abstract: PADC track detectors are very useful de<strong>vi</strong>ces to qualify and quantify e.g. the fluence of 

charged particles impinging from a given source. For low particle fluence registered as etched track 

density is proportional to the fluence, indicating that yield estimates can be made from track densities. 

Nevertheless, for high fluencies the greatest contribution to the total error is the effect of track 

overlapping (systematic error). Furthermore, mean track diameters and its dispersion increase at longer 

etching times so that the quantity of overlapped tracks increases, leading to saturation. For high track 

density >6000 Tracks cm-2, the probability of underestimating the actual value of track density 

increases with the use of a semi-automatic system compared with a naked eye, nevertheless in both 

cases the quantity of non overlapped tracks can be determined with sufficient accuracy. To solve the 

problem of overlapping tracks a study was carried out, considering the stochastic character of the 

overlapping process and the fact that even in the case of monoenergetic charged particles 

perpendicularly impacting on a detector (e.g. in vacuum), induced etched tracks will have different 

diameters due to the straggling effect, so that some distribution of diameters will be obtained. The 

distributions of non overlapped tracks for different track diameters, dimensions of the field <strong>vi</strong>ew and 

total tracks induced in the detector surface were determined using Monte Carlo simulation techniques. 

Extreme distributions of non overlapping tracks were obtained for very low or very high simulated 

track quantities, while for intermediate values the distributions were well described by Gaussians. A 

model for the track overlapping process was developed, considering the dependence of the quantity of 

non overlapping tracks with the number of simulated tracks by a second order homogeneous 

differential lineal equation, whose solution contains only one parameter that is related with the track 

and field <strong>vi</strong>ew areas. Then, using a simple method of successive approximations the actual number of 

total induced tracks (which is proportional to the fluence) can be determined from the knowledge of the 

amount of non overlapping tracks, dimensions of the field <strong>vi</strong>ew and average track diameter. 

Corresponding author: D. Palacios: sanjuro.perdomo@gmail.com 

10

INVITED TALKS 

12

Fundamental neutron physics in Mexico 

Libertad Barron 

Instituto de Física, Universidad Nacional Autónoma de México 

Ap. Postal 20-364 

México, D.F. 

The utilization of cold and ultra cold neutrons from intense sources in different experiments offers a 

unique opportunity to address important questions in fundamental physics. At present, students and 

researches from Mexican institutions are involved in a number of experiments in the area of 

fundamental neutron physics, where parity <strong>vi</strong>olation observables or neutron beta decay are studied, 

focusing on the design and construction of parts of the apparatus for these experiments. In this work 

some of the projects in which we are currently participating and the developments achieved so far will 

be described. 

13

Extending studies of the fusion of heavy nuclei to the neutron rich region 

using accelerated radioactive ion beams. 

Dan Shapira 

Physics Di<strong>vi</strong>sion, ORNL(*) 

One of the stated goals for proposed and existing facilities that produce and accelerate radioactive ion 

beams is to explore and achieve a new understanding of the mechanisms of reactions leading to the 

synthesis of the hea<strong>vi</strong>est nuclei. 

Nuclear synthesis of two large nuclei into a single entity is a complex multistep process. The beam 

intensities of radioactive ions accelerated at present day facilities are not sufficient to synthesize super 

heavy elements. However the study of the isospin dependence of nuclear synthesis and the many 

processes competing with it can be carried out at present day facilities. Of special interest are cases 

where the interacting nuclei and the synthesized product are extremely neutron rich. The effects of 

neutron excess on the reaction processes leading to the formation of the synthesized nucleus that 

emerged in earlier studies are poorly understood and sometimes counter intuitive. 

Results from measurements performed at HRIBF, as well as our plans for future measurements and the 

equipment being prepared will be presented. 

(*)Notice: 

This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 

with the U.S. Department of Energy’s Office of Nuclear Physics. The United States Government retains 

and the publisher, by accepting the article for publication, acknowledges that the United States 

Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce 

the published form of this manuscript, or allow others to do so, for United States Government purposes. 

14

Fusion De<strong>vi</strong>ces as Plasma Based Fast Neutron Sources 

J. J. E. Herrera-Velázquez 

1 

Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México 

A.P. 70-543, Ciudad Universitaria, 04511 México, D.F. México 

While the study of fusion de<strong>vi</strong>ces has been generally motivated by the quest to design commercial 

fusion reactors, the road to this goal is still far in the future. As far as magnetic fusion is concerned, 

such a goal implies that the ratio of fusion power to heating power Q, should be at least as high as 20 

(the next generation machine, ITER, is designed to reach Q ~ 10). This will still require a proper 

understanding of burning plasmas - in which most of the heating power is delivered by fusion reactions 

- of which there is no experimental experience so far. However, enough expertise has been developed 

on Q ~ 1 deuterium-tritium tokamaks, and according to present knowledge, there are no surprises to be 

expected by Q ~ 2. Machines with such characteristics can be used as plasma based fast neutron 

sources, which could be used for research on materials needed for the fusion programme, but also for 

other applications, such as actinide transmutation of nuclear waste from fission reactors. Other kinds of 

machines, such as the axisymmetric mirror could be considered for this purpose. On the other hand, the 

inertial confinement fusion programme has got to the point in which the National Ignition Facility 

(NIF) in the USA, and the Laser Megajoule in France, will soon be able to achieve ignition (Q = ∞) in 

spaced shots, which will probably be the highlight of fusion research in 2010. When a much smaller 

amount of neutrons is required, the plasma focus, which is still a widely used research workhorse in 

many developing countries can be used. The interesting advancements in this case, have not been so 

much in the scaling up of the de<strong>vi</strong>ces, which have stalled at stored energies of ~ 1 MJ and neutron 

yields in deuterium of ~ 10 12 neutrons per shot, but in scaling them down. Presently there are de<strong>vi</strong>ces 

with storage energies as small as 0.1 J, with yields as small as 10 2 neutrons per shot (albeit with low 

reproducibility). 

15

STUDY OF 15 N BY 14 C(p,p) 14 C USING POLARIZED PROTON BEAM 

G. Murillo, M. Fernández, J. Ramírez, R. Policroniades, A. Varela, 

Instituto Nacional de Investigaciones Nucleares, 

E. Chávez 

Instituto de Física, Universidad Nacional Autonoma de México, 

S. E. Darden + , S.Sen, 

University of Notre Dame, Notre Dame,IN, USA, 

R. M Prior, 

North Georgia College and State University, Georgia, USA 

+Deceased 

Angular distributions of cross sections and analyzing powers have been measured for 14 C(p, p) 14 C for 

proton energies between 3.7 and 11.0 MeV. The measurement were carried out in 50 keV intervals 

between 3.7 and 5.0 MeV, and in 20 keV intervals between 5.0 and 11.0 MeV, in the region of narrow 

resonances are using 10 keV intervals. A number of strong resonances are seen. A phase-shift analysis 

of the elastic scattering data thus far has yielded level parameters of ten states in 15 N in the excitation 

energy region 13.7-21.0 MeV. The results generally are in good agreement with pre<strong>vi</strong>ous work. 

Pacs: 25.40.Cm, 27.20.+n, 29.27.Hj. 

Keywords: polarized proton beam, nuclear structure, elastic scattering. 

16

Neutron scattering studies of the magnetic interactions in the geometrically 

frustrated triangular lattice antiferromagnet CuFeO 2 

Jaime A. Fernandez-Baca 1,2 , Feng Ye 1 , Randy Fishman 3 and Tsuyoshi Kimura 4 

1 Neutron Scattering Science Di<strong>vi</strong>sion, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, 

USA 

2 

Department of Physics and Astronomy, University of Tennessee-Knox<strong>vi</strong>lle, Knox<strong>vi</strong>lle, Tennessee 

37996-1200, USA 

3 Materials Science and Technology Di<strong>vi</strong>sion, Oak Ridge National Laboratory, Oak Ridge, Tennessee 

37831, USA 

4 Di<strong>vi</strong>sion of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyokana, 

Osaka 560-8531, Japan 

Neutrons have unique properties that make them an ideal probe of condensed matter systems. They 

have wavelengths and energies comparable to the typical atomic distances and collective excitations in 

solids, making them suitable to study the crystalline structures and the dynamics of materials. They 

have no electric charge which gives them the ability to penetrate to the bulk of most materials. 

Neutrons also have a magnetic moment which makes them very useful to study the magnetic structures 

and magnetic excitations in magnetic materials. In this talk we will describe all the properties that 

make neutrons unique to study condensed matter systems and will present examples of recent research 

in the study novel materials. We will also describe the neutron scattering facilities at Oak Ridge 

National Laboratory, the new Spallation Neutron Source (SNS) and the High Flux Isotopes Reactor 

(HFIR). We will also describe in some detail the progress in the study of the magnetic interactions in 

the geometrically frustrated geometric triangular lattice antiferromagnet CuFeO 2 , a system that exhibits 

multiferroic beha<strong>vi</strong>or upon doping or under the application of magnetic field. 

The SNS and the HFIR at SNS are funded by the Di<strong>vi</strong>sion of Scientific User Facilities, Office of Basic 

Energy Sciences, US Department of Energy. 

17

Radiological Accident: Fast Neutrons Absorbed Dose 

Estimation using Hair 

L. Paredes-Gutiérrez 

Instituto Nacional de Investigaciones Nucleares, 

Carretera México-Toluca s/n, La Marquesa, C.P. 52179 Ocoyoacac, Méx. México. 

lydia.paredes@inin.gob.mx 

Abstract 

Due to the possible radiological impact that <strong>vi</strong>ctims of a criticality accident in a nuclear reactor, can 

undergo or the accidental exposures to neutron sources or with neutron beams of radiation accelerators, 

one should rely on alternate methods to have a quick estimate of the fast neutrons absorbed dose that 

<strong>vi</strong>ctims received while exposed to mixed fields of radiation (fast neutrons - gamma). The purpose of 

applying these alternate methods, is to corroborate the information collected from personal dosimeters, 

collect information to reconstruct and analyze the conditions of the accident, identify the irradiated 

personnel, calculate an estimate of the absorbed dose by the personnel, and to support the immediate 

radiological and clinical care of the affected personnel. In order to do these alternate methods, a 

biological sample such as hair is needed. The hair samples have been placed on phantom and irradiated 

in the exposition room of the research nuclear reactor of Mexican Nuclear Center in two powers, 500 

kW and 1 MW. Human hair contains keratin fibers with S-32, these fibers are activated when exposed 

to fast neutrons (E n >2.5 MeV). This exposure leads to the creation of P-32 which emits beta radiation 

with energy of 1.7 MeV and has a half life of 14 days. The measurement of the P-32’s acti<strong>vi</strong>ty makes it 

possible to determine the correlation between acti<strong>vi</strong>ty and the fast neutron absorbed dose. In order to 

get a representative measurement, a hair sample > 0.25 g is required. If samples are taken from hair in 

different parts of the body, it is possible to estimate variations in the exposure levels among the body. 

Samples can be processed for 2 methods, direct or indirect techniques; it is evaluated with a detection 

system utilizing liquid scintillation. It was determined that the threshold of the fast neutron absorbed 

dose, using this methodology, is >0.5 Gy. 

18

HAWC, a new high energy gamma detector in Mexico 

Belmont-Moreno E. por la colaboración HAWC, 

Instituto de Física, Universidad Nacional Autónoma de México. 

HAWC (High Altitude Water Cherenkov detector) is a binational (USA-Mexico) collaboration which 

joins 11 institutions from Mexico and 14 from the United States to construct in Mexico a front line 

instrument to study the universe in the High energy spectrum, 1-100Tev. The HAWC observatory is 

being constructed in the Sierra Negra Volcano, Puebla, at an altitude of 4100m. It is compound of 300 

water cherenckov detectors to detect atmospheric showers in an area of 20,000 m 2 . Given an aperture 

of <strong>vi</strong>sion of 35 0 , HAWC will continue the sky observation with a sensiti<strong>vi</strong>ty 15 times greater than the 

predecessor MILAGRO. We will study galactic and extragalactic <strong>vi</strong>olent events, and will search for 

physics e<strong>vi</strong>dence beyond the Standard Model. 

----------------------------------------- 

HAWC, un nuevo detector para gammas de alta energia en México 

HAWC es una colaboración binacional (México-Estados Unidos), que incluye 11 instituciones 

mexicanas y 14 estadounidenses para establecer en México un instrumento de vanguardia para observar 

el Universo en rayos gamma de altas energías, 1 - 100TeV. El Observatorio HAWC por sus iniciales 

High Altitude Water Cherenkov detector, se está construyendo en volcán Sierra Negra, Puebla, a 

4100m sobre el nivel del mar, se basa en 300 detectores de Cherenkov en agua para detectar cascadas 

atmosféricas en un área de 20,000 m 2 . Con un campo de <strong>vi</strong>sión de 35 0 HAWC continuamente 

observará el cielo sobre él con una sensibilidad 15 veces mayor que su antecesor el detector Milagro. 

Se estudiarán procesos <strong>vi</strong>olentos del universo, galácticos y extragalácticos y buscará e<strong>vi</strong>dencia de 

Física fundamental más allá del modelo estándar. 

PACS number. 95.55.Ka 

19

Center for Irradiation of Materials of Alabama A&M University 

D. ILA, R. L. Zimmerman, C. Muntele, and B. Chhay 

Center for Irradiation of Materials 

Alabama A&M University 

Normal, AL 35762-1447 USA 

The Center for Irradiation of Materials @ AAMU (http://cim.aamu.edu) established in 1990 to serve 

the University in its research, Education and ser<strong>vi</strong>ces the need of the local community and Industry. 

CIM irradiation capabilities oriented around two tandem type ion accelerators with several beam lines 

pro<strong>vi</strong>ding high resolution Rutherford backscattering spectrometry (RBS), MeV focus ion beam, high 

energy ion implantation and irradiation damage studies, particle induced x-ray emission (PIXE), 

particle induced gamma emission (PIGE), and ion induced nuclear reaction analysis in addition to fully 

automated ion channeling. One of the two tandem ion accelerators designed to produce high flux ion 

beam for high fluence MeV ion implantation and high fluence ion irradiation damage study. The 

facility is well equipped with variety of surface analysis systems, such as SEM, ESCA, as well as 

scanning micro-Raman analysis, UV-VIS Spectrometry, luminescence spectroscopy, Thermal 

conducti<strong>vi</strong>ty, electrical conducti<strong>vi</strong>ty, IV/CV systems, Mechanical test systems, AFM, FTIR, Voltmetry 

analysis as well as low energy implanters, Ion Beam Assisted Deposition and MBE systems. In this 

presentation we will demonstrate how the facility pro<strong>vi</strong>des ser<strong>vi</strong>ces to schools, industries and how CIM 

has contributed to the recent invention of fabrication of highly efficient thermoelectric materials as well 

as invention of direct/one-step fabrication of nanopores in polymers. The center has world class 

summer training and special topic courses for students from across the globe. The plan is to complete a 

proton beam writing during FY09-10. 

Sponsors: Supported in part by AAMU Research Institute, NASA, DOE, NSF-EPSCoR and industries. 

20

Uses of Radiation Damage in Insulators 

Leticia Tavera 1 , Miguel Balcazar 2 , Jorge Ascencio 1 

1 Universidad Autónoma del Estado de México 

2 Instituto Nacional de Investigaciones Nucleares 

miguel.balcazar@inin.gob.mx 

Abstract 

Analyses of induced and natural radiation damage in insulators pro<strong>vi</strong>de a useful tool in material science 

and geophysics studies. An over<strong>vi</strong>ew acti<strong>vi</strong>ty of the Radiation Physics group at the Nuclear Centre of 

México is presented. Concerning material science two acti<strong>vi</strong>ties are discussed: the high neutron 

radiation on a nuclear-power-reactor vessel was simulated using direct bombardment of Ni ions on steel 

samples, in order to simulate the neutron flux from the core, which gradually degrades the ductility of 

the steel in the vessel over its lifetime of several decades; aging effects in the vessel can then be derived 

from this simulation. A second acti<strong>vi</strong>ty is the possible nano wires production of uniform geometry from 

nanopors in plastics as replicas of heavy ion damage in plastics; a detailed experimental study presented 

by analyzing range and rate of energy loss of 238 U and 137 Xe in a polycarbonate plastic. Concerning 

geophysics studies, the thermal instability of radiation damage produced by spontaneous Uranium 

fission in minerals pro<strong>vi</strong>des a thermal history of a particular geological site; the rate of energy lost of 

both fission fragments from Uranium fission in different crystals are related with experimental reported 

values; a discussion of potential applications for oil prospecting is presented. 

21

Thermoluminescent detectors for neutron 

ambient dose equivalent H*(10) determination 

Teodoro Rivera Montalvo*, Juan Azorín Nieto**, Pedro González Martínez & , 

Andrea Velasco Vázquez* and Héctor René Vega-Carrillo && 

*Centro de investigación en Ciencia Aplicada y Tecnología Avanzada-Legaria, IPN. 11500 México DF 

trivera@ipn.mx 

**Universidad Autónoma Metropolitana-Iztapalapa, 09340 México D.F. 

& Instituto Nacional de Investigaciones Nucleares, 52750 Edo de México. 

&& Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas 

98068 Zacatecas, Zac. Mexico 

Abstract 

In this work, a system consisting of two thermoluminescent phosphors, zirconium dioxide (ZrO 2 ) and 

lithium fluoride doped with magnesium, cooper and phosphorus (LiF:Mg,Cu,P) is proposed to measure 

neutron ambient dose equivalent H*(10). This new system uses the difference in the TL readings of 

both types of detectors for estimating the neutron ambient dose equivalent. The high sensiti<strong>vi</strong>ty of this 

new system makes it practical for neutron dosimetry in radiation protection. 

22

Electron dynamics of transition metal compounds studied 

with resonant soft x-ray scattering. 

J. Jiménez-Mier, 1 G. Herrera-Pérez, 1 P. Olalde Velasco, 1,2 G. Carabalí, 1 P. de la Mora, 3 E. 

Cha<strong>vi</strong>ra, 4 J. Denlinger, 2 W. Yang, 2 A. Moewes, 5 R. Wilks, 5 L. Weinhardt, 6 C. Heske, 6 O. Fuchs. 7 

1 Instituto de Ciencias Nucleares, UNAM, México, 2 The Advanced Light Source, Lawrence Berkeley 

National Laboratory, USA, 3 Facultad de Ciencias, UNAM, México, 4 Instituto de Investigaciones en 

Materiales, UNAM, México, 5 Department of Physics and Engineering Physics, University of 

Saskatchewan, Canada, 6 Department of Chemistry, University of Nevada, Las Vegas, USA 

7 Experimentelle Physik II, Universität Würzburg, Germany. 

High resolution experimental results for resonant soft x-ray scattering of transition metal compounds 

are presented. The compounds studied are the ionic transition metal di-fluorides, ionic and covalent 

orthovanadates and members of the La 1-x Sr x CoO 3 perovskite family. In all compounds we studied the 

transition metal L 2,3 edge and also the ligand (oxygen or fluorine) K edge. For the ionic compounds the 

transition metal data are in good agreement with atomic multiplet ligand field calculations that include 

charge transfer effects. Density functional calculations are needed to compare with the ligand scattering 

data. The experimental data show region between valence and conduction bands in the di-fluorides has 

several d-excited states. At the L 2 edge of the ionic orthovanadates we found the signature of a fast 

Coster-Kronig decay process that gives raise to a very localized emission peak. Changes in the 

oxidation sate in the La 1-x Sr x CoO 3 compounds are observed at both the metal L2,3 edge and the oxygen 

K edge absorption spectra. The emission spectra also indicate a change from de-localized to localized 

3d orbitals as x increases from 0 to 0.3. 

23

XRF analysis of obsidian 

T. Calligaro, M.I. López, J.A. López, and A. Bezur 

This Study focuses on an elemental analysis of the obsidian of one of Murillo's paintings housed at the 

Houston Museum of Fine Arts. The study was performed using XRF with a mobile instrument and 

comparing the trace elements found to a reference material (NIST SRM278). Conclusions regarding 

the provenance of the obsidian were drawn upon these results. 

24

Synchrotron radiation study of the uranium chemical species 

electrodeposited for alpha spectrometry sources 

D. C. Burciaga-Valencia (1), C. G. Méndez (1), H. Esparza-Ponce (1), A.M. Beesley (2), M. T. 

Crespo (3), L. Fuentes (1), L. Fuentes-Montero (1), M. E. Montero-Cabrera (1) * 

(1) Advanced Materials Research Center, Chihuahua, Mexico. e-mail:elena.montero.cimav.edu.mx 

(2) School of Chemical Engineering and Analytical Science, The University of Manchester, United 

Kingdom 

(3) CIEMAT, LMRI, Madrid, Spain 

*Corresponding author. 

Alpha spectrometry (AS) has applications in nuclear decay data measurements, en<strong>vi</strong>ronmental, 

geological and nuclear wastes studies and other works requiring determination of actinide contents. AS 

sources must be thin and uniform, producing small FWHM to obtain accurate measurements. AS 

sources produced by electrodeposition consist of a radioactive deposit onto a metallic substrate 

(cathode of the electrolytic cell). Natural U sources prepared by the Hallstadius method have codeposited 

Pt, originated from the dissolution of the anode during the electrodeposition. Recently [1] 

have reported a study on the morphology and spatial distribution of the U/Pt deposits with the related 

chemical speciation of U, using SEM/EDX, XPS and XAFS. 

The purpose of this work is to explain the structure of the Pt/U deposits. We have obtained new spectra 

of the U LIII edge XAFS by total electron yield at Stanford Synchrotron Radiation Lightsource 

(SSRL), BL 2-3. Grazing incidence (GI) XRD patterns were obtained at SSRL, BL 11-3. GI-XRD 

patterns show a bimodal distribution of grain sizes of Pt, with dimensions ∼5 and 20 nm; schoepite 

diffraction signals suggest grain dimensions of ∼5 nm, i.e. with low crystallization. XAFS spectra were 

fitted assuming two different structures: uranyl hydroxide and schoepite, and results were compared. U- 

U path shows low intensity that also may be a result of low crystallization. 

[1] A M Beesley et al. Appl. Rad. Isotopes 67, 1559–1569 (2009) 

25

Determination of neutron dose contribution in medical LINAC 

Juan Azorín Nieto*, Teodoro Rivera Montalvo**, Ana Lilia Cano Aguilar**, José Antonio 

Calderón Arenas*, Claudio Furetta*, Luis Felipe Villaseñor Navarro & , 

Héctor René Vega-Carrillo && 

*Universidad Autónoma Metropolitana-Iztapalapa, 09340 México D.F. 

azorin@xanum.uam.mx 

**Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada-Legaria, IPN, 11500 México 

D.F. 

& Hospital General de México. 06726 México D.F. 

&& Unidad Académica de Estudios Nucleares de la Universidad Autónoma de Zacatecas 

98068 Zacatecas, Zac. Mexico 

Abstract 

The increased use of LINACs with accelerating voltage higher than 10MV in clinical radiotherapy is 

producing an increasing demand of accurate dosimetric measurements of the photon induced neutron 

contamination of the radiotherapy beams, due that the associated bremsstrahlung X rays may produce 

neutrons as a result of subsequent photonuclear reactions with the different materials constituting the 

accelerator head. Thermal neutron fluences can be measured with TLD-600/TLD-700 pairs arranged in 

both a bare and a cadmium (Cd) foil covered methacrylate box. Neutron response of TL dosemeters 

irradiated with two different neutron sources has been investigated. The shape of the glow curve of 

these TLDs after irradiation in a medical LINAC and in a PuBe neutron source has been studied to 

verify the contribution of neutrons to an additional dose to staff, patients and the general public, due to 

photonuclear reactions generating neutrons from medical LINACs. 

26

Bioaccumulation of chemical elements in Tillandsia usneoides L. 

at the industrial zone of Tula, in Central Mexico. 

M. A. Martínez-Carrillo 1 , C. Solís 1* , E. Andrade 1 , R. I. Beltrán-Hernández 2 , K. Isaac- 

Olivé 3 , C. A. Lucho-Constantino 4 , M. C. López Reyes 5 , L. C. Longoria 5 . 

1 Instituto de Física, Universidad Nacional Autónoma de México,04510 México D. F. 2 Centro de 

Investigaciones Químicas, Universidad Autónoma del Estado de Hidalgo. Carretera Pachuca- 

Tulancingo km. 4.5. 42067. Pachuca, Hidalgo. 3 Facultad de Medicina. Universidad Autónoma del 

Estado de México, Paseo Tollocan s/n, esq. Jesús Carranza, Toluca, 50120 Estado de México. 

4 Universidad Politécnica de Pachuca, Carretera Pachuca-Cd. Sahagún Km. 20. Hidalgo, México. 

5 Instituto Nacional de Investigaciones Nucleares (ININ), Salazar, 50045, Edo. de México. 

Abstract 

This study deals with the application of nuclear analytical techniques to analyze trace elements in the 

biological monitor Tillandsia usneoides. Biological monitors pro<strong>vi</strong>des an alternative advantageous way 

of particulate matter sampling in air pollution studies, since there is no need of special sampling 

de<strong>vi</strong>ces, accumulation time can be as long as desired. T. usneoides, which occurs naturally throughout 

Mexico, was used to monitor air quality of Tula-Vito-Apasco (TVA) industrial corridor at central 

Mexico. This area is considered one of the critical zones of the country because of atmospheric 

contaminants high concentration. Particulate matter is regulated by Mexican Norms, but it chemical 

composition is not. Plants were transplanted from a clean en<strong>vi</strong>ronment to four sites at the TVA 

corridor, and exposed for 12 weeks from February to April 2008. Trace element accumulation of plants 

was determined by PIXE and NAA. Results reveal differences in trace elements distribution among 

sites in the TVA corridor. Furthermore, anthropogenic elements (S, V) and crustal elements (Ca) in T 

usneoides exhibit high levels. Results show that monitoring with T. usneoides allows a first 

approximation of air sources to pro<strong>vi</strong>de insights of the atmospheric pollution in the TVA corridor. 

PACS: 07.88.+y, 78.70, 82.80.-d, 92.60.Sz 

Key words: PIXE, NAA, biomonitors, Tillandsia usneoides, trace elements, Mexico. 

27

Improvement to nuclear track counting systems by laser light scattering 

C. Vázquez-López a , B.E. Zendejas-Leal a , 

J.I. Golzarri b and G. Espinosa b 

a Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. 

Ave. IPN 2508, Col. San Pedro Zacatenco. México 07360, D.F. México. 

b Instituto de Física. Universidad Nacional Autónoma de México 

Apartado Postal 20364, 01000 México, D.F. México 

cvlopez@fis.cinvestav.mx 

Abstract 

In this work we present a de<strong>vi</strong>ce to measure the angular distribution of the diffuse optical transmittance 

produced by etched nuclear tracks in polyallyl diglycol carbonate (PADC) detector. The de<strong>vi</strong>ce makes 

use of a stepper motor to move an array of four photodetectors around the sample in 1.8 degree steps. 

The effect of additional scatterers is reflected in the width at half height of the curves. This quantity 

was found to be a linear function of the nuclear track density. The width in degrees at half height is 

described by the following equation: 

−5 

W ( σ ) = 2.73× 

10 σ + 3.8 , (1) 

where σ is the surface track density in cm -2 . Equation 1, was observed to be valid in the range of σ 

from zero to 2.8 x 10 5 cm -2 , using a neutron 241 Am-Be source. 

Keywords: Transmittance; Angular distribution; PADC (CR-39); Nuclear tracks. 


28

Photomultiplier Principles & the Application for 

Thermal and Fast Neutron Detection 

Richard H. Olster, Da<strong>vi</strong>d T. Seagraves, Shawna L. Eisele, Christopher W Bjork, 

William A. Martinez, Leonard L. Romero, Michael W. Mallett, Michael A. Duran 

Los Alamos National Lab 

Charles R. Hurlbut: 

Eljen Technology, part of Ludlum Measurement Inc. 

Carlos Chapa 

Ludlum Measurement Inc 

A photomultiplier tube (PMT) is a vacuum phototube capable of detecting light in the ultra<strong>vi</strong>olet, 

<strong>vi</strong>sible and near infrared ranges of the electromagnetic spectrum. The light detected by the 

photomultiplier is converted and amplified into an electrical signal. In today’s markets, the 

photomultiplier tubes are widely used in applications including nuclear medicine, oil exploration, 

physics research, radiation detection and others. The paper will focus in the construction, operating 

principles, important fundamental characteristics of photomultipliers, and the application of the ADIT 

side<strong>vi</strong>ew bialkali 1-inch PMT as the detector for Neutrons in the PRESCILA (Proton Recoil 

Scintillation) neutron detector. This PMT, in combination with two different scintillation materials, can 

measure thermal and fast neutrons with energies up to 100 MeV. The PRESCILA DETECTOR was 

designed by Los Alamos National Lab in USA in conjunction with Eljen Technology a subsidiary of 

Ludlum Measurement. The whole detector is made and assembled at Ludlum’s factory located in 

Sweetwater, TX. 

29

The detailed deposited energy in lung tissue from radon´s 

daughters calculated by a Montecarlo code 

Arturo Ángeles Carranza 

Instituto Nacional de Investigaciones Nucleares 

Carretera México Toluca S/N, La Marquesa, Ocoyoacac, México, C.P. 52750 

arturo.angeles@inin.gob.mx 

Abstract 

Radon and radon´s daughters inhalation result in deposit of them in respiratory tract structures, Po-214 

and Po-218 alpha emitters half lifes are 3.1 min and 150 s respectively, the cilia movement it is not 

able enough to clear the deposited material because radon´s daughter relati<strong>vi</strong>ty short half lifes 

compared with the lung tissues transit lifes, for that practically all alpha energy is deposited in the 

neighborhood place where the material was deposited. 

The alpha energy range in tissue is near some micrometer tens, that’s the epitelial cell´s layers order 

dimensions in bronchi and bronchiolar regions. 

Knowing air radon concentrations by an optimal measurement method like nuclear track, using a 

reliable deposit and clear models for material in the lung airways and detailed anatomical model for 

bronchi and bronchiolar regions the absorbed dose in that cell layers were calculated using a 

Montecarlo code for each bronchi and bronchiolar cylindrical named generations. 

Knowing the absorbed dose in mentioned tissues the equivalent dose was calculated then effective 

equivalent dose and committed dose for laboral ambit. 

30

ANN AND NEUTRONS 

Hector Rene Vega-Carrillo * , Víctor Martín Hernández-Dá<strong>vi</strong>la* /+ 

Jose M. Ortiz-Rodriguez **/+ , Ma Rosario Martinez-Blanco * 

Ediardo Gallego & , Alfredo Lorente & 

*Unidad Academica de Estudios Nucleares de la Universidad Autonoma de Zacatecas 

Calle Cipres 10, Fracc. La Peñuela, 98068 Zacatecas, Zac. Mexico 

fermineutron@yahoo.com 

**Unidad Academica de Ingenieria Electrica de la Universidad Autónoma de Zacatecas 

Av. Ramón López Velarde #801, Col. Centro, Zacatecas, México, C.P. 98000 

+ Universidad de Córdoba, España, Depto. de Electrotecnia y Electrónica, Escuela Politecnica 

Superior, Avda. Menendez Pidal, s/n - Escuela Politecnica Superior, Córdoba, España 

morvymm@yahoo.com.mx; mrosariomb@yahoo.com.mx 

& Universidad Politécnica de Madrid, Depto. de Ingeniería Nuclear 

ETSI Industriales, C. José Gutierrez Abascal, 2, 28006, Madrid, España 

eduardo.gallego@upm.es; alfredo.lorente@upm.es 

Abstract 

Artificial Intelligence technology has been applied in neutron spectrometry and dosimetry. Bonner 

sphere spectrometer (BSS) was proposed in 1960, this spectrometer is able to determine the neutron 

spectrum from thermal up to 20 MeV. For larger energies, shells of high Z materials are used in some 

of the polyethylene spheres. The spectrometer has been successfully applied in different neutron fields, 

also several detectors have been utilized, some of these are 6 LiI(Eu) scintillator, Thermoluminscent 

dosimeters (TLD 600 and TLD 700), 10 BF 3 , 3 He, Track detectors and Au and Dy foils. Three main 

drawbacks of BSS are the weight, wasting time in the measurements and the need of an unfolding 

procedure to get the neutron spectra. In the last decade has been proposed several procedures to do the 

unfolding, some of these are MAXED [1] and FRUIT [2] , this last has a user-friendly interface, that 

facilitates the procedure. Mostly of unfolding methods requires an initial guess spectrum, to avoid this 

the Artificial Neural Networks (ANN) has been proposed [3] as an alternative procedure, in the last years 

this research line has evolved using Taguchi method and Genetic Algorihms [4] to optimize the ANN 

training. In this work the performance of ANN for spectrometry and dosimetry in actual neutron fields 

is shown. 

[1].- Reginatto M et al., (2002). Nucl. Instrum. Meth. Phys. Res., A 476: 242 

[2].- Bedogni R et al., (2007). Nucl. Instrum. Meth. Phys. Res., A 580: 1301 

[3].- Vega-Carrillo HR et al., (2006). Radiat. Meas., 41: 425. 

[4].- Ortiz-Rodriguez JM et al., (2009). IEEE cerma 2009: 113 

31

POSTER SESSION 

32

Absorbed dose by a biological sample 

located at a Nuclear Reactor Beam Port 

Maritza R. Gual 1 ; Héctor René Vega-Carrillo 2 ; Massimo Zucchetti 3 ; Felix Mas 4 

1 Instituto Superior de Tecnologías y Ciencias Aplicadas 

Habana, Cuba 

2 Unidad Académica de Estudios Nucleares de la UAZ 

Apdo. Postal 336, 98000 Zacatecas, México 

3 Dip. Energet, Politécnico Torino 

Corso Duca degli Abruzzi, 24, CP 10 129, Torino, Italy 

4 Instituto de Física, Universidad de São Paulo 

Rua do Matao, trav R.,no 187, Ciudade Universitaria, Butanta 

CEP: 05508-900, Sao Paulo, Brazil. 

The absorbed dose by a biological sample located at the nuclear reactor´s beam port has been 

determined. The work was carried out at the beam port BH#3 located in the Nuclear Reactor IEA-R1. 

This facility is at the Brazilian Nuclear and Energy Research Institute (IPEN). Neutron and photon 

doses were estimated using Monte Carlo methods with the MCNPX code. A realistic model of beam 

port was built including the <strong>vi</strong>al with the biological sample; the source term for neutrons and photons 

was obtained using the DOT3.5 code. Absorbed dose by the sample was evaluated using two MCNP 

tallies. Calculated doses were compared with doses measured with thermoluminiscent dosimetry. 

33

18 MV Linear Accelerator Bunker 

Luis Hernandez-Adame, Antonio Baltazar-Raigosa, Edmundo Escareño-Juarez , 

Carlos Alberto Mares-Esparza, Carlos Hernandez-Villasana, 

Héctor Contreras-Sandoval and Héctor René Vega-Carrillo 

Unidad Academica de Estudios Nucleares de la Universidad Autonoma de Zacatecas 


dameluis@hotmail.com; fermineutron@gmail.com 

Abstract 

Worlwide the NCRP 151 is utilized as guide to calculate the shielding features for linear accelerator for 

radiotherapy. In this work a program was developed that utilize these criteria as well other currently 

used in Mexico. A typical bunker has been designed using those criteria. Linear accelerators working 

above 8 MV produce an undesirable neutron field, in this work a Monte Carlo calculation has been 

carried out to evaluate the shielding features of bunker walls, and door, to shield neutrons. 

. 

34

241 Am-Be source term simulation with Monte Carlo methods 

Méndez Villafañe R., Guerrero Araque J.E. 

CIEMAT, Laboratorio de Metrología de Radiaciones Ionizantes, 

Avda. Complutense, 22, 28040, Madrid, España. 

roberto.mendez@ciemat.es; jorgeenrique.guerrero@ciemat.es 

Gallego Díaz E. Lorente Fillol A. Töre Candan 

Universidad Politécnica de Madrid, Depto. de Ingeniería Nuclear 



Ortiz-Rodríguez J.M. *1,3 , Martínez-Blanco M.R 2 ., Vega-Carrillo H.R. 1,2 

Universidad Autónoma de Zacatecas, U. Académicas: 1 -Ing. Eléctrica, 2 -Est. Nucleares 


3 -Universidad de Córdoba, España, Depto. de Electrotecnia y Electrónica, Escuela Politecnica 


morvymm@yahoo.com.mx; mrosariomb@yahoo.com.mx; fermineutron@yahoo.com 

Abstract 

An automated panoramic irradiator with a 3 Ci 241 Am-Be neutron source is installed in a bunker-type 

large room at the Universidad Politécnica de Madrid (UPM). It was recently modified and a detailed 

Monte Carlo simulation has been carried out to characterize the neutron field; calculations were carried 

out with the MCNPX code. For a large 241 Am-Be, the source term definition in the MCNPX input is 

one of the unsolved problems in the Neutron Metrology. Usually, the ISO Am-Be spectrum is used but 

this is only appropriate for light encapsulation and for a particular composition and dimensions. The 

UPM-Am-Be neutron source (outer diameter = 19.05 mm, outer height = 50.29 mm) has got double 

304 L stainless steel encapsulation and it is 4.24 mm thick. It is a forty-years-old neutron source and, no 

data about its material composition is available. An <strong>international</strong> comparison with four different 

spectrometric systems based on Bonner Spheres has been carried out recently and a set of detailed 

measurements rotating the source have been made to determine its anisotropy. From these results 

several MCNPX models have been proposed in order to get an spectrum as similar as possible to ISO 

spectrum but according with anisotropy and spectra measurements. 

e-mail corresponding main author: roberto.mendez@ciemat.es 

35

Neutron spectra in a linear accelerator for radiotherapy 

Jorge Luis Benites Rengifo*, Víctor Martín Hernández-Dá<strong>vi</strong>la**, 

Teodoro Rivera Montalvo & and Hector Rene Vega-Carrillo** 

*Centro Estatal de Cancerlogía de los Ser<strong>vi</strong>cio de Salud de Nayarit 

& CICATA-IPN 

**Unidad Academica de Estudios Nucleares de la Universidad Autonoma de Zacatecas 



Abstract 

Neutron spectra and H*(10) has been measured inside and outside a 15 MV LINAC. Measurements has 

been carried out with a Bonner sphere spectrometer with two detectors TLDs pairs (inside) and 6 LiI(Eu) 

scintillator (outside). With two neutron monitor areas the H*(10) has been measured inside and outside 

the treatment room; Bare and Cd-covered Au foils were also utilized to verify the intensity of thermal 

and above thermal neutrons inside the room. A Monte Carlo calculation was also carried out where the 

hall was modeled and neutron spectra were calculated. Neutrons inside the hall produce neutron 

activation where short life radioisotopes are produced, to identify those isotopes a gamma-ray 

spectrometer was utilized; also the ambient dose equivalent due to decay of those radioisotopes was 

measured around the patient couch. 

36

Comparing the Neutron spectra unfolding features using two codes 

Ortiz-Rodríguez J.M.* 1 , Martínez-Blanco M.R 2 ., Vega-Carrillo H.R. 1,2 



3 -Universidad de Córdoba, España, Depto. de Electrotecnia y Electrónica, Escuela Politecnica 



Abstract 

Gallego Díaz E., Lorente Fillol A. 




Méndez Villafañe R., Los Arcos Merino J.M., Guerrero Araque J.E. 



roberto.mendez@ciemat.es; jm.losarcos@ciemat.es; jorgeenrique.guerrero@ciemat.es 

The “Laboratorio de Metrología de Radiaciones Ionizantes” (LMRI), of the CIEMAT, Spain, has a 

Bonner spheres spectrometric system (CIEMAT-BSS) with 12 moderator polyethylene spheres, a 3 He 

thermal neutrons detector and their own response matrixes. To get the neutrons spectra, the LMRI uses 

the unfolding package known as “Unfolding with Maxed and Gravel” (UMG 3.3), developed at the 

Physikalisch-Technische Bundesanstalt, (PTB), Germany. The MAXED code is based on the maximum 

entropy principle while GRAVEL relies on least-square methods. As an alternative procedure to solve 

the neutron spectra unfolding problem the ANN technology was used. By using the systematic 

methodology known as “Robust Design of Artificial Neural Networks” (RDANN), developed at the 

Universidad Autónoma de Zacatecas (UAZ), México, was designed the ANN architecture for the 

CIEMAT-BSS. After the network was designed, the knowledge stored at the same was extracted, and a 

graphical user interface was constructed and added as an extra programming routine of the computer 

program known as “Neutron Spectrometry and Dosimetry by means of Artificial Neural Networks” 

(NSDann) developed at the UAZ. In this work, the results obtained with both neutron spectra unfolding 

codes UMG and NSDann are compared. With the same BSS counts rate as input data for the two 

spectrometric codes, the neutrons spectra were unfolded and then compared by means of the computer 

tool known as “Neutron spectrometry and Dosimetry Tool Box“ (NSDTB). 

e-mail corresponding main author: morvymm@yahoo.com.mx 

37

Multichannel Analyzer in Field Programmable Gate Array 

Luis Sinhue Gaytan-Jiménez**, Víctor Martín Hernández-Dá<strong>vi</strong>la**, 

Oscar Osvaldo Ordaz-García* and Hector Rene Vega-Carrillo** 

*Unidad Académica de Ingeniería Eléctrica de la Universidad Autonoma de Zacatecas 

**Unidad Academica de Estudios Nucleares de la Universidad Autonoma de Zacatecas 


<strong>vi</strong>c.mc68010@gmail.com 

Abstract 

It developed a multichannel analyzer or pulse height (MCA) of 8192 channels in one FPGA (Field 

Programmable Gate Array). For this was used of hardware description language VHDL which 

facilitates the electronic design making it a program that is downloaded (embedded system) in the 

FPGA. At the entrance of the analog to digital converter (ADC) with analog circuitry that fits the 

spectroscopic signal amplifier. The spectrum is shown by a port VGA (Video Graphics Array) FPGA 

system itself. 

38

Shielding features of Quarry Stone 

Carlos Hernandez-Villasana, Héctor Contreras-Sandoval, 

Luis Hernandez-Adame, Antonio Baltazar-Raigosa, 

Edmundo Escareño-Juarez, Carlos Alberto Mares-Esparza and Héctor René Vega-Carrillo 




Abstract 

The attenuation coefficient for gamma-rays has been determined for quarry stone. In some region in 

Mexico, like Zacatecas, quarry stone is widely utilized as a decorative item in churches, houses and 

buildings. In some locations with quarry stone there are installed dental and medical x-ray facilities 

where the presence of quarry stone in the walls is not taken into account for shielding purposes, in this 

work the properties of quarry stone to shield x and γ-rays have been determined. Characterization was 

carried out by calculations and by measurements; calculations were made with MCNP where a detailed 

model of experimental setup was carried out. In the measurements 10 pieces 10 x 10 cm 2 of different 

thickens were prepared to evaluate the photons transmission as the quarry stone thickness is increased. 

It was noticed that transmitted photons decay away as the shield thickness in increased, these results 

were fitted to an exponential function were the linear attenuation coefficient was estimated. Also, using 

XCOM code the linear attenuation coefficient from several keV to 100 MeV was estimated. From the 

comparison between Monte Carlo results, actual experiment and XCOM calculations agreement was 

found between 5%. Thus, for 0.662 MeV gamma-rays the attenuation coefficient of quarry stone, 

whose density is 2.413 g-cm -3 , is 0.1798 cm -1 , this mean a x 1/2 = 3.9 cm, x 1/4 = 7.7 cm, x 1/10 = 12.8 cm, 

and x 1/100 = 25.6 cm. Ha<strong>vi</strong>ng the information of quarry stone performance as shielding from x-ray to γ- 

ray energies gives us the chance to use this material to shield x and γ-ray facilities. 

39

Measuring 40 K to estimate total K concentration. 

Edmundo Escareño-Juarez, Carlos Alberto Mares-Esparza, 

Carlos Hernandez-Villasana, Héctor Contreras-Sandoval, 

Luis Hernandez-Adame, Antonio Baltazar-Raigoza, Héctor René Vega-Carrillo 

Unidad Académica de Estudios Nucleares de la Universidad Autonoma de Zacatecas 

C. Cipres 10, Fracc. La Peñuela, 98068 Zacatecas, Zac. Mexico 


Abstract 

Total potassium concentration has been determined by measuring the 1.46 MeV gamma ray emitted 

during 40 K decay. In nature there are three K isotopes: 39 K, 40 K and 41 K, this last is radioactive with a 

half life of 10 9 years. In nature, 40 K is in 0.0117% and this is measured in order to estimate the total 

amount of potassium. Potassium plays and comporting role in growing and reproduction of animals and 

plants. Due to decay properties and because it is essential to humans 40 K is important for radiological 

protection. Due to secular equilibrium the γ-ray emission rate of 40 K is proportional to total 40 K 

concentration and can be used to estimate the total amount of K. In this work a set of 40 K calibrating 

sources has been prepared and was utilized with NaI (Tl)-based spectrometric γ-ray system to mesure 

the 40 K concentration in several samples; with this information total K was evaluated. 

40

Validity of Special Relati<strong>vi</strong>ty Theory using the Compton Scattering 

Héctor Contreras-Sandoval, Luis Hernandez-Adame, Antonio Baltazar-Raigoza, 

Edmundo Escareño-Juarez, Carlos Alberto Mares-Esparza, 

Carlos Hernandez-Villasana, Héctor René Vega-Carrillo 

Unidad Académica de Estudios Nucleares de la Universidad Autonoma de Zacatecas 

C. Cipres 10, Fracc. La Peñuela, 98068 Zacatecas, Zac. Mexico 


Abstract 

The validity of the Special Relati<strong>vi</strong>ty theory has been tested using the Compton scattering. Since 1905 

several experiments has been carried out to show that time, mass, and length change with the velocity, 

in this work the Compton scattering has been utilized as an simple way to show the validity to 

relati<strong>vi</strong>ty. The work was carried out through Monte Carlo calculations and experiments with a 137 Cs 

source, a gamma-ray spectrometer with a 3”x3” NaI(Tl) detector. The pulse-height spectra at 0, 20, 40, 

60, 80 and 90 o were collected and the photopeak shift was noticed as a function of scattering angle. 

This information was utilized to determine the relationship between the electron´s mass and energy 

using the Compton “knee” possition, the obtained results were contrasted with two collision models 

between photon and electron, one model was built using the Classical physics and another using the 

Special Relati<strong>vi</strong>ty theory. It was found that calculations and experiments results fit to collision model 

made using the Special Relati<strong>vi</strong>ty. 

41

Nitrogen determination with Prompt Gamma Neutron Activation 


Héctor Contreras-Sandoval, Luis Hernandez-Adame, 

Antonio Baltazar-Raigosa, Edmundo Escareño-Juarez and Héctor René Vega-Carrillo 




Abstract 

A prompt gamma activation analysis system has been designed for non-destructive determination of 

total nitrogen in organic samples. The system includes a 239 Pu-Be radionuclide neutron source within a 

paraffin howitzer. When neutrons collides with paraffin are moderated and reach the analyzing sample 

where neutrons are absorbed producing prompt gamma-rays that are detected by a gamma-ray 

spectrometer with a 3” X 3” NaI(Tl). To avoid the detection of gamma-ray produced by the neutron 

source a layer of lead is included; to avoid the radioactivation of sodium in the scintillator a shield 

made of boric acid powder is also included. The design has been carried out using Monte Carlo 

methods were prompt gamma rays produced by neutron capture reactions in the sample is detected by a 

NaI(Tl) detector. To evaluate the design performance the Monte Carlo tally was to estimate the gammaray 

spectrum were the 10.8 MeV photon, characteristic of nitrogen captures, is noticied. In order to 

optimize the howitzer several designs were tried where moderator, source, sample and detector were 

modified. 

42

Changes in the neutron spectra inside an 18 MV LINAC treatment room 

Antonio Baltazar-Raigoza, Edmundo Escareño-Juarez, 


Hector Contreras-Sandoval, Luis Hernandez-Adame, Hector Rene Vega-Carrillo 




Abstract 

A Monte Carlo study has been carried out in order to determine the effect, on the neutron spectrum and 

ambient dose equivalent, of different materials located in the <strong>vi</strong>cinity of a 18 MV linear accelerator. 

Calculations were performed with the MCNP code where the neutron spectra and the ambient dose 

equivalent were determined in several locations inside the treatment room. Calculations were carried 

out with the head in vacuum, with air, with and without the walls and with and without a head phantom. 

From these calculations it was noticed how the neutron spectrum is changing with the position inside 

the head and as the materials are added. 

43

Dose in eyes, thyroid and gonads during chest x-ray radiography 

Rogelio González González,* José Alberto Guera Moreno,* 

Víctor Martín Hernández Dá<strong>vi</strong>la*, Teodoro Rivera Montalvo**, 

Hector Rene Vega-Carrillo* 



** CICATA-IPN 


Abstract 

Dosimetric measurements were carried out in the radiology department form Hospital General of 

Fresnillo in the aim to determine the dose related to scattered radiation when thorax radiography is 

taken. Measurements were performed in the stationary and mobile X-ray equipments located at the 

Intensive care unit, and at the Newborn Intensive Care Unit. The dose at the entrance surface of eyes, 

thyroid and gonads was measured. Measurements were carried out when thorax radiography was taken 

in adult and newborn patients. The dose was measured with CaSO 4 :Dy thermoluminiscent dosimeters 

that were located on eyes, thyroid and gonads. With the fixed equipment the doses were 39 to 90 μGy, 

while for the mobile equipment was from 35 to 81 μGy. On the other hand, the dose varies from 35 to 

81 μGy in the adults, and from 20 to 52 μGy in neonates. Although these values are small we must to 

point out that is due to scatter radiation reaching sensitive areas in the body. With the doses the risk to 

develop a radiation-induced cancer was evaluated being 0.92x10 -6 for each radiography taken in 

newborns, and 3.23x10 -6 for adults. Due to this findings it is proposed to add in the Mexican vaccine 

card a section where the doses being recorded in order to have hard data to realize, in the near future, 

epidemiological studies. 

44

Dosimetry in the Radiology Department at the HGF 

José Alberto Guera Moreno,* Rogelio González González,* 

Víctor Martín Hernández Dá<strong>vi</strong>la*, Teodoro Rivera Montalvo**, 

Hector Rene Vega-Carrillo* 



** CICATA-IPN 


Abstract 

From January to August 2009 a dosimetric study was carried out at radiology department of the 

Hospital General Fresnillo “Dr. José Haro Á<strong>vi</strong>la” in the aim to determine the radiation levels in the 

en<strong>vi</strong>ronment. The mean dose received by two radiation workers from the radiology department was 

also determined. Measurements were performed with CaSO 4 :Dy thermoluminiscent dosimeters 

en<strong>vi</strong>ronmental; an active-detector monitor was also utilized to measure the dose rate in the 

en<strong>vi</strong>ronmental survey that was carried out in halls with permanent X-ray units, the R-X 2 and 

mammography were adult inpatients are attended while, the hall were the portable X-ray unit is 

utilized, was the UCIN 2 where newborn inpatients are attended. Personal dosimetry was done in two 

X-ray technicians that eventually did use all the X-ray units. The ambient dose equivalent and the 

personal dose equivalent were measured in the en<strong>vi</strong>ronmental survey and in the personnel dosimetry 

respectively. Both dosimetric determinations were below the limits defined by the ICRP 

recommendations and the Mexican regulation. It was noticed that X-ray technicians did apply 

procedures that avoid unnecessary exposures; however it was also observed uncertainty and doubts in 

the nursery personnel. With the purpose to reduce the dose levels and to keep a better communication 

between all professional of this hospital several recommendations are done such as, actualization, 

refreshment and to define a Quality Committee. 

45

Performance of Artificial Neural Networks and Genetical 

Evolved Artificial Neural Networks unfolding techniques 

Ortiz-Rodríguez J.M. 1 , Martínez-Blanco M.R 2 ., Vega-Carrillo H.R. 1,2 

Universidad Autónoma de Zacatecas, U. Académicas: 1 Ing. Eléctrica, 2 Est. Nucleares 


3 Universidad de Córdoba, España, Depto. de Electrotecnia y Electrónica, Escuela Politecnica 











Abstract 

With the Bonner sphere spectrometer neutron spectrum is obtained through an unfolding procedure. 

Monte Carlo methods, Regularization, Parametrization, Least-squares, and Maximum Entropy are some 

of the techniques utilized for unfolding. In the last decade methods based on Artificial Intelligence 

Technology have been used as Genetic Algorithms and Artificial Neural Networks have been 

developed in order to overcome the drawbacks of pre<strong>vi</strong>ous techniques. Nevertheless the advantages of 

Artificial Neural Networks still it has some drawbacks mainly in the design process of the network, vg 

the optimum selection of the architectural and learning ANN parameters. In recent years the use of 

hybrid technologies, combining Artificial Neural Networks and Genetic Algorithms, has been utilized 

to. In this work, several ANN topologies were trained and tested using Artificial Neural Networks and 

Genetically Evolved Artificial Neural Networks in the aim to unfold neutron spectra using the count 

rates of a Bonner sphere spectrometer. Here, a comparative study of both procedures has been carried 

out. 

46

Neutron Spectrometry using Artificial Neural Networks 

for a Bonner Sphere Spectrometer with a 3 He Detector 




3-Universidad de Córdoba, España, Depto. de Electrotecnia y Electrónica, Escuela Politecnica 



Abstract 









The neutron spectra unfolding problem and the dose equivalent calculations are the most complicated 

tasks in radiation protection, mainly because it is a complex technique, highly dependent of the neutron 

energy, and a precise knowledge on neutron spectrometry is highly essential for all dosimetry-related 

studies as well as many nuclear physics experiments. They are not tri<strong>vi</strong>al problems and the researchers 

have mentioned the necessity to develop additional measuring techniques to enhance the actual workers 

monitoring system. In pre<strong>vi</strong>ous works have been reported neutron spectrometry and dosimetry results, 

by using the ANN technology as alternative solution, starting from the count rates of a Bonner spheres 

system with a 6 LiI(Eu) thermal neutrons detector, 7 polyethylene spheres and the UTA4 response 

matrix with 31 energy bins. In this work, an ANN was designed and optimized by using the RDANN 

methodology for a Bonner spheres system with a 3 He neutron detector, 12 moderator spheres and a 

response matrix for 60 energy bins. For the ANN design process a neutrons spectra catalog compiled by 

the IAEA was used. From this compilation, the neutrons spectra were converted from lethargy to 

energy spectra. Then, the resulting energy fluence spectra were re-binned by using the MCNP code to 

the corresponding energy bins of the 3 He response matrix before mentioned. With the response matrix 

and the re-binned spectra the counts rate of the Bonner spheres system were calculated and the resulting 

re-binned neutrons spectra and calculated counts rate were used as the ANN training data set. 

47

User-friendly interface to run the Monte Carlo 

Neutral Particle code for radiation physics 


Universidad Autónoma de Zacatecas, U. Académicas: 1 Ing. Eléctrica, 2 Est. Nucleares 


3 Universidad de Córdoba, España, Depto. de Electrotecnia y Electrónica, Escuela Politecnica 











Abstract 

Monte Carlo methods are considered as an experimental method where the output is mean value of 

responses obtained with repeated random sampling. Monte Carlo methods tend to be used when it is 

infeasible or impossible to obtain an exact result using deterministic methods. The MCNP is a generalpurpose 

Monte Carlo code for the transport of particles like neutron, photon, and electron, isolated or 

coupled. This code is worldwide pervasively utilized and its origin goes back to the early years of Los 

Alamos National Laboratory. MCNP has been developed to run an almost all computational platforms; 

one of this is the PC under MS-DOS en<strong>vi</strong>ronment. In this work a, user-friendly, graphical interface was 

designed under the LabVIEW to execute MCNP code where there is no need to use MS-DOS 

commands. Through the interface the user can run the code and pickup the MCNP output file. The 

interface has several routines that make easy the MCNP operation and the recovery of useful 

information from output file. 

48

Design and construction of a Multichannel Analyzer 

Manuel Alejandro Pulido-Gaytán*, Alma Karen Gonzalez-Alcalde*, 

Alejandro Chacón-Ruiz*, Héctor René Vega-Carrillo*,** 

*Unidad Académica de Ingeniería Eléctrica 


Av. Ramon Lopez Velarde 801, Col. Centro, 98000, Zacatecas, Zac. México 

manuel_pulidogaytan@hotmail.com 

**Unidad Académica de Estudios Nucleares 


C. Cipres 10, Fracc. La Peñuela, 98068, Zacatecas, Zac. México 


Abstract 

A PC based multichannel analyzer, MCA, has been designed and built using operational amplifiers to 

treat the electronic signals and a data acquisition card to process and channeling the electronic pulses. A 

user-friendly program to control the MCA was also developed using the MATLAB software. The MCA 

was tested with a PIN type photodiode as detector and an alpha-particle source containing 239 Pu, 241 Am 

and 244 Cm isotopes where the pulse height spectra was collected and the alpha-particle peaks were 

utilized to calibrate in energy the MCA. 

49

Thermo-transferred Thermoluminescence in potassium-yttrium and potassiumlutetium 

double fluorides doped with terbium 

A. Gallegos 1 , J. Azorín 2* , J. A.Díaz-Góngora 1 , R. Licona 3 , F. Rivas 3 , G. Hernández- Cocoletzi 3 , T. 

Rivera 1 , N. Khaidukov 4 , C. Furetta 1 

1 Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada-IPN, 

Legaria 694 Col. Irrigación, México D.F. 11500, Mexico 

2 Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco, 186 

Col. Vicentina, México D.F. 09340, México 

3 Facultad de Ciencias Químicas, BUAP, 14 Sur y San Claudio CU. Puebla Pue. IFUAP, BUAP, 14 Sur 

y San Claudio CU. Puebla Pue., Mexico 

4 Institute of General and Inorganic Chemistry, Lenin SK 11 Prospect 31, 

Moscow 117907, Russia 

azorin@xanum.uam.mx 

Abstract. 

This paper presents results of studying the thermo-transferred thermoluminescence (TTTL) 

phenomenon in double fluoride of potassium and yttrium doped with terbium (K 2 YF 5: Tb) at different 

impurity concentrations (0.8%, 0.95% and 0.99%) and in double fluoride of potassium and lutetium 

doped with terbium (K 2 LuF 5: Tb) at 0.99% of impurity concentration. 

Pre<strong>vi</strong>ously to study the TTTL phenomenon, structural characterization and chemical composition of the 

materials were determined. The structural studies were conducted using a scanning electron microscope 

(SEM); meanwhile, chemical composition was analyzed using energy dispersive X-ray spectroscopy 

(EDS). 

Isothermal decay of K 2 LuF 5: Tb showed an anomalous fading similar to that of K 2 YF 5: Tb which can be 

associated to the isothermal-transfer phenomenon which consists in transferring the shallow trapped 

electrons to deeper traps. 

50

A study and characterization of the optically stimulated luminescence response of 

commercial SiO 2 optical fiber to gamma radiation 

Guillermo Espinosa 

Instituto de Fisica, Universidad Nacional Autonoma de México 

Apartado Postal 20-364, 01000, México, D.F. 

espinosa@fisica.unam.mx 

Abstract 

Everyday, is coming more common the use of optically stimulated luminescence (OSL) as radiation 

measurement methodology. Although the OSL response characteristics of several chemical compounds 

such as aluminum oxide, beryllium oxide, potassium chloride and fused quartz have already been 

studied, research into new OSL materials is of continuing scientific and commercial interest. The 

thermoluminescence (TL) response characteristics of commercially, Nokia ® SiO 2 optical fiber have 

pre<strong>vi</strong>ously been studied. The aim of this work is to characterize the OSL response of the SiO 2 optical 

fiber to gamma radiation. 

The material preparation, pre-annealing, aliquot preparation, and OSL reading procedures are presented 

together with preliminary results of the investigation into the OSL response characteristics of the SiO 2 

optical fiber. The total luminescence was found to be a linear function of gamma radiation dose within 

the range investigated (15.6 to 93.8 mGy). The experimental method yielded high reproducibility and 

very low residual effect. The OSL fading curve suggests that the optical fiber can be used for OSL 

measurements for approximately 150 hours (around 6 days) after exposure to gamma radiation. Taking 

into account the limits imposed by this fading, optical fiber can be successfully used as an OSL 

material to measure radiation doses such as those resulting from radiological accidents. 


51

Radon concentration levels in 16th and 17th century’s churches and convents. 

Sn Sebastian Church at Municipio La Paz Mexico State. 

F. Juarez 1 , O. Diaz 1 , Ma. D. Islas 2 , J. I. Golzarri 3 , G. Espinosa 3 

1 Instituto de Geofísica, Universidad Nacional Autónoma de México, Apartado Postal 20-364, México, 

D.F., México 

2. Facultad de Química, Universidad Nacional Autónoma de México, Edificio D, Ciudad Universitaria, 

04510 México, D.F. México 

3 Instituto Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, México, D.F., 

México 

The present work is a complementary to the pre<strong>vi</strong>ous paper on indoor radon measures at Churches in 

Mexico City. In this part we take as study area the church Sn Sebastian Martir in the Municipio La Paz 

Mexico State. This building is from 16th Century too. The soil in this area is sediment a pyroclastic 

material from Chimalhuacan volcano. Four hundred years ago on this site was a water spring 

. 

In this work we found the correlation between geological fractures and radon emanation. To measure 

the concentration of indoor radon, passive detector based on CR-39 polycarbonate, and active monitor 

(Georadar) were choused 

The results shown a … 


52

Long term Indoor Radon Measurements in the Pelletron 

laboratories at the UNAM Physics Institute 

Rickards, J., López, K., Hernandez-Ibinarriaga, I., Golzarri, J.I., Espinosa, G. 


Apartado Postal 20-364 

01000, México, D.F. 

The results of a year of continuous measurement of the indoor radon concentration levels in the 

building where the 3 MV Pelletron particle accelerator is located, as well as in some adjacent 

laboratories, are presented. 

This study has three basic objectives: (a) to know the actual values of the levels of indoor radon in this 

installation, where a large number of personnel spend many hours, and sometimes days; (b) assess the 

radiological risk from radon inhalation for personnel working permanently in the laboratory, as well as 

incidental users; and (c) establish, if necessary, time limits for continuous permanence on the location 

for indoor radon exposure. 

Passive nuclear track detectors and dynamic systems were employed, covering the four seasons of the 

year. For the calculation of internal dose, the “Radon Indi<strong>vi</strong>dual Dose Calculator” was used 

(http://www.wise-uranium.org/rdcrn.html). 

The results indicate that the indoor radon levels are below the recommended levels by the USEPA (200 

Bq/m 3 ) in workplaces. The measurements help to establish levels for workplaces in Mexico. 


53

Structural modification of Al surfaces using high energy proton radiation 

Barragán Vidal. A., Cruz-Manjarrez Flores H., Pineda Santamaría J.C., Flores Morales L. 


Apartado Postal 20-364, CP 01000 D.F. 

México 

barragan@fisica.unam.mx, hector@fisica.unam.mx 

The purpose of the project is to change the structure of surface of metals, Our procedure to do that is 

using high energy protons to irradiate the metal surface maintained at cryogenic temperature and 

vacuum conditions. In a second step, the sample is maintained in an intense magnetic field and finally 

irradiated with a laser beam. 

A highly polished Aluminum sample (dimensions are 0.750” diameter and 0.080” thick) is irradiated 

with protons, in the course of the irradiation process, sample is maintained at cryogenic temperature in 

order to produce a textural change. The critical temperature of aluminum to produce a change is less 

than -190° Celsius. 

The samples were irradiated with the use the 0.7 keV Van de Graaff particle accelerator and the 

e<strong>vi</strong>dence of change after irradiation was obtained by x ray diffraction analysis; a comparison of initial 

no irradiated sample x ray spectrum, with the irradiated sample spectrum, it shows a change of intensity 

of the characteristic peaks. 

Results of magnetic field effects on the sample and a complete study are presented in an extended work 

to be published. 

54

Preliminary results in the development of 

a versatile spectrometer for X-ray fluorescence 

J. Miranda, A.A. Espinosa, J.N. Martínez, J.C. Pineda, M.A. Veytia 

Instituto de Física 

Universidad Nacional Autónoma de México 

Apartado Postal 20-364 

01000 México, D.F. 

México 

email: miranda@fisica.unam.mx 

This work shows progress in the construction of an X-ray spectrometer allowing the use of different 

types of primary radiation as a radioactive source ( 241 Am), or tubes with anodes of different metals (Cu, 

Rh or W). In addition, the advantages of this spectrometer are its low cost, possibility of exchanging 

detectors to improve efficiency at different X-ray energy ranges (Si-PIN or CdTe detectors), its use in 

vacuum or atmospheric pressure, or the possibility of irradiating various types of targets. Furthermore, 

it is feasible to modify the geometry so a secondary target may be used to increase sensiti<strong>vi</strong>ty for light 

elements, or for using polarized X-rays as exciting radiation. This spectrometer is designed originally to 

be employed in Atomic Physics and en<strong>vi</strong>ronmental sciences studies. 

The technical support of M. Cuautle and J.I. Cruz is acknowledged. 

55

Neutron Characterization at the FN-II Dense Plasma Focus 

F. Castillo 1 , G. Espinosa 2 , I. Gamboa- de Buen 1 , J.I. Golzarri 2 , J.J.E. Herrera 1 , José Rangel 1 

1 

Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México 

A.P. 70-543, México, Distrito Federal 04511 México 

2 


A.P. 20-365, México, Distrito Federal 01000, México 

Plasma foci are efficient plasma based neutron sources, when deuterium is used as the filling gas. The 

dense plasma focus FN-II is a small de<strong>vi</strong>ce (4.7 kJ), in which the emission of deuterium fusion neutrons 

(2.45 MeV) are studied. Three methods are currently used; silver activation counters and CR-39 nuclear 

track detectors, for time integrated and angular distribution studies, and BC 400 scintillators coupled to 

photomultiplier tubes for spectra studies. The neutron yield has been found to have isotropic and 

anisotropic components, the former gi<strong>vi</strong>ng the largest contribution. Also, the neutron spectrum, 

measured at 90 o of the axis de<strong>vi</strong>ce, is broadened, peaking at energies slightly larger than 2.45 MeV. 

These can be interpreted as the consequence of coexisting neutron generation mechanisms, which will 

be discussed in this work. There has also been a dosimetric study of the laboratory with TLD 

dosimeters, which will be presented in this paper. 


56

THE PRODUCTION OF 3 H AND 11 C RADIOACTIVE BEAMS AT ININ 

TANDEM ACCELERATOR 

J. N. Martínez 3 ,A. Varela 1 , G. Murillo 1 , A. Huerta 2 , R. Policroniades 1 , E. Chavez 2 , M.E. Ortiz 2 , , 

E. Moreno 1 , L. Barrón 2 , 

1.- Laboratorio del Acelerador Tándem, Departamento de Aceleradores, ININ. Mexico 

2.-Instituto de Física (IFUNAM), UNAM, Mexico. 

3.- Facultad de Ciencias, UNAM, Mexico. 

Abstract 

The results obtained for the production and characterization of a radioactive 3 H and 11 C beams, by 

means of the in flight technique at the tandem laboratory of the National Institute of Nuclear Research, 

Mexico is shown. The radioactive beams production technique described here, uses the well known 

Associated Particle Technique (APT) with the reactions 2 H( 2 H, 3 H)p and 2 H( 10 B, 11 C)n, in order to 

obtain a biunivocal correspondence between the radioactive 3 H and 11 C particles and the associated 

protons and neutrons respectively. A discussion concerning the possible use of this facility in nuclear 

spectroscopy studies is introduced. 

57

THE DETECTION OF COSMIC NEUTRONS USING 

AN EXTENDED RANGE BONNER SPECTROMETER 

A. Varela 1 , A. Huerta 2 , R. Policroniades 1 , E. Chavez 2 , M.E. Ortiz 2 , G. Murillo 1 , E. Moreno 1 , J. N. 

Martínez 3 

1.- Laboratorio del Acelerador Tándem, Departamento de Aceleradores, ININ. Mexico 

2.-Instituto de Física (IFUNAM), UNAM, Mexico. 

3.- Facultad de Ciencias, UNAM, Mexico. 

By using the extended range Bonner spectrometer designed and constructed at ININ, the pulse high 

spectra obtained for the extended spheres is re<strong>vi</strong>ewed. The spectra were taken near the Instituto de 

Física located at Mexico City. The metalic cores used, inside the extended spheres, consists of Copper, 

Lead Bismuth and stainless steel ones. 

58

Radiation response of polyminerals fraction from Hibiscus sabdariffa L foodstuffs 

E. Cruz-Zaragoza 1 , S. Guzmán 1 , V. Chernov 2 , M. Barboza-Flores 2 

1 Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México. 

A.P. 70-543, México 04510 D.F., México. 

2 Centro de Investigación en Física, Universidad de Sonora, A.P. 5-088, Hermosillo 83190, Sonora, 

México. 

1 ecruz@nucleares.unam.mx 

The polymineral inorganic fraction content in some foodstuffs processed by industrial irradiation has 

luminescent property under thermally stimulation, that property is known as thermoluminescence (TL) 

phenomena. This property can be measured in order to determine if the foodstuffs were pre<strong>vi</strong>ously 

irradiated. The aim of this work is to study the main TL characteristics of the polymineral fraction 

extracted from Roselle flower (Hibiscus sabdariffa L.) which is widely grown in Mexico and 

commonly used for food flavoring. 

The polymineral fraction of commercial Roselle flower (Hibiscus sabdariffa L.) was analysed by TL 

measurements for detection the irradiated samples. Different grain sizes of polymineral were selected 

for the TL analysis. The glow curves intensities show that the TL is depends of the grain sizes. The TL 

emission as the dose-reponse, signals reproducibility, and the effects on TL of UV radiation and under 

sunlight were evaluated when the samples were exposed. The glow curves show two peaks, about 90 

and 125 °C, these peaks are ascribed to the quartz, and the broad part of the glow curves (125-250 °C) 

may be correspond to the albite present in the Roselle samples. The Tm-Tstop method shows that the 

glow curves of the Roselle contains five glow peaks between 100-250 °C. The values of the activation 

energy related to the traps in the polymineral fraction were calculated using the initial rise (IR) method. 

We are gratefully to DGAPA-UNAM for support the project IN121109-3 PAPIIT. 

59

Gamma radiation effects in commercial Coriandrum sativum L 

for consumption in Mexico 

B. C. Ruiz 1 , E. Cruz-Zaragoza 2 , M. C. Wacher 3 , M. Barboza-Flores 4 

1 

Departamento de Agricultura y Ganadería, A.P. 305, Universidad de Sonora, Hermosillo 83190, 

Sonora, México 

2 Unidad de Irradiación y Seguridad Radiológica, Instituto de Ciencias Nucleares, Universidad 

Nacional Autónoma de México, A.P. 70-543, México 04510 D.F., México 

3 Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma 

de México, México 04510 D.F., México 

4 Centro de Investigación en Física, Universidad de Sonora, A.P. 5-088, Hermosillo 83190, Sonora, 

México 

2 ecruz@nucleares.unam.mx 

Ionizing radiation is an effective process for disinfecting and prolonging the shelf-life of several food 

products. Food irradiation may be one of the most significant contributions to public health in the 

developing countries. Following the irradiation spices or foodstuffs it is necessary to identify the 

radiation dose effects on the microbiological content of the processed foodstuffs. In this work, the 

thermoluminescence (TL) and microbiological load were measured as a function of irradiation dose. 

The irradiation processing was performed using the 60 Co irradiation facility, Gamabeam 65IPT at the 

Nuclear Science Institute-UNAM and a dose rate of 98.4 Gy/min. The aim of this work is to report the 

main thermoluminescent characteristics of the inorganic polyminerals extracted from dehydrated 

cilantro spice, including the structure of the glow curves, TL response as a function of dose (0.5-700 

Gy), reproducibility over 12 cycles of subsequent irradiation, and fading effects during storage periods 

of 30 days. Furthermore, the kinetics properties of the polyminerals were studied using a Computerized 

Glow Curve Deconvolution (CGCD). Microbiological measurements showed that at 0.5 kGy of the 

cilantro´s samples, the initial charge of aerobic mesophiles diminished around 99.9% and the total 

coliforms (871 000 ucf/g) was less than 100. The samples remained fresh for a period of 10 days and 

were suitable for human consumption according to official health and irradiation regulations in Mexico. 

Also the TL method was found useful for detection of irradiated foodstuffs. 

We are gratefully to DGAPA-UNAM for support the project IN121109-3 PAPIIT, and Oficina de 

Intercambio Académico UNAM-UNISON. 

60

Baccharis Salicifolia as a revealer of uranium contamination 

in arid en<strong>vi</strong>ronments analogous to San Marcos, Chihuahua. 

Montero, M.E. 

CIMAV, Chihuahua, Mexico 

61

vi international symposium on radiation physics - Universidad ...

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