Program - Brookhaven National Laboratory

Differential Cross Sections for the 40 Ca(n,α) 37 Ar Reaction in the MeV Neutron Energy
Region
Jinhua Han, Jiaming Liu, Xiang Liu, Xiao Fan, Jinxiang Chen, Guohui Zhang, State Key Laboratory of
Nuclear Physics and Technology, Institute of Heavy Ion Physics, Peking University, Beijing 100871,
China. Yu. M. Gledenov, M. V. Sedysheva, V. A. Stolupin, Frank Laboratory of Neutron Physics, JINR,
Dubna 141980, Russia. G. Khuukhenkhuu, Nuclear Research Centre, National University of Mongolia,
Ulaanbaatar, Mongolia. P. J. Szalanski, University of Lodz, Institute of Physics, Lodz, Poland.
Differential cross sections and angle integrated cross sections for the 40 Ca(n,α0) 37 Ar, 40 Ca(n,α1,2) 37 Ar and
40 Ca(n,α3,4,5) 37 Ar reactions are measured in the neutron energy range of 4.0 6.5 MeV using a doublesection
gridded ionization chamber and two back-to-back CaF2 samples. Experiments were performed
at the 4.5 MV Van de Graaff Accelerator of Peking University. Monoenergetic neutrons were produced
through the 2 H(d,n) 3 He reaction with a deuterium gas target. Foreground and background were measured
in separate runs. A 238 U sample set on the sample changer in the gridded ionization chamber and a
BF3 long counter were utilized for absolute neutron flux calibration and for neutron flux normalization,
respectively. Present results are compared with existing measurements and evaluations. Model calculations
are performed using the TALYS code and reasonable agreements are achieved between measurements and
calculations. The present work was financially supported by the National Natural Science Foundation of
China (11175005) and the Russian Foundation for Basic Research (RFBR-NSFC 07-02-92104).
PR 92
2011/2012 Nuclear Data Review
Norman E. Holden, National Nuclear Data Center, Brookhaven National Laboratory.
The results of a periodic review and evaluation of nuclear data that was published in the scientific literature
over the past few years are presented. Recommendations from these evaluations are published annually
or biennially in the CRC Handbook of Chemistry and Physics. Some items discussed include the status
of new chemical elements added to the Periodic Table. Many chemical elements have had their previous
values of atomic weight and uncertainty replaced by interval values of upper and lower bounds. Data on
revised values for the isotopic composition of the elements are reviewed and new recommended isotopic
abundance values are presented. Other data that are reviewed include radioactive half-lives, magnetic
dipole moments, electric quadrupole moments, alpha, beta and gamma ray energies and intensities. Latest
values are presented for various nuclides including half-lives for very long-lived double beta decay and
double electron capture, long-lived alpha and beta decay. Half-life values for the isotopes of the very heavy
elements (trans-meitnerium elements) are tabulated, including spontaneous fission values.
PR 93
Alpha Decay Measurement of 144 Nd
Felix Krueger, Kai Zuber, Institute of Nuclear and Particle Physics.
To improve the value of the half life of long living 144 Nd a Frisch grid ionisation chamber was build. These
devices are generally used for measurements on large areas samples and provide a good energy resolution
for alpha spectroscopy. A new approach with digital pulse shape combined with charge production in
different volumes in the chamber and the signature of different particles allow a better signal to background
ratio. Some results of the new background suppressing method and the status and results of the current
measurement on 144 Nd will be presented.
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