Program - Brookhaven National Laboratory

T. Martinez, D. Cano-Ott, J. Castilla, A.R. Garcia, J. Marin, G. Martinez, E. Mendoza, C. Santos, D.
Villamarin, CIEMAT, Madrid (Spain). J. Agramunt, A. Algora, J.L. Tain, CSIC-IFIC, Valencia (Spain).
C. Bhattacharya, K. Banerjee, VECC, Kolkata (India). H. Pentillä and A. Jokinen, JYFL, Jyväskylä
(Finland).
The knowledge of the β-decay properties of nuclei lying far from stability contributes decisively to our
understanding of nuclear phenomena. The accurate measurement of the half-lives, distribution of decay
probabilities and particle emission probabilities provides essential data for the fields of fundamental physics,
nuclear structure, astrophysics and nuclear technology. Beta-decay studies of exotic nuclei are one of the
main goals of the DEcay SPECtroscopy (DESPEC) [1] experiment at the future FAIR facility [2] and at
many other RIB facilities around the world. In particular, the measurement of the delayed neutron data,
emission probabilities (Pn) and neutron energy spectra of neutron rich nuclei constitute an important
challenge due to the key role that delayed neutrons play in relevant fields like in the nucleosynthesis rprocess
or in the kinetic control of advance reactor concepts. In order to determine the neutron energy
spectra from neutron precursors as well as the emission probabilities, a time-of-flight spectrometer has been
proposed. High energy resolution, high efficiency as well as n-γ discrimination capability and modularity
are the main requirements for such a spectrometer. The MOdular Neutron time of flight SpectromeTER -
MONSTER has been designed at CIEMAT after an extensive work consisting in Monte Carlo simulations
and experimental tests of available materials. The spectrometer is based in BC501A liquid scintillators
cells. A demonstrator is currently being assembled and tested. It consists in a set of 30 cylindrical cells of
20 cm diameter and 5 cm thickness, each one with an intrinsic efficiency ranging from 50% at 1 MeV to
28% at 5 MeV. The data taking will be made with high performance flash ADC boards also designed at
CIEMAT. Each board will have a 12 bit resolution, 1Gsample/s frequency, and FPGA for the trigger logic,
a DSP for the pulse shape analysis and 2 Gbytes internal memory for waveform storage. The demonstrator
will be first used in early 2013 at the Cyclotron laboratory of the University of Jyväskylä.
Corresponding author: J.L. Tain
[1] HISPEC/DESPEC Collaboration web page: http://personal.ph.surrey.ac.uk/ phs1zp/Home.html [2]
FAIR, Facility for Antiproton and Ion Research, web page: http://www.fair-center.eu
PR 20
Composite Shielding Building Materials and Building Blocks for the Construction of
Objects with a Low Internal Level of Ionizing Radiation
Jiri Suran, Petr Kovar, Czech Metrology Institute, Prague.
New composite building materials and building blocks based on aggregate, with a low internal content
of radionuclides, have been developed and submitted for patent protection, suitable for the construction
of objects with a low internal level of ionizing radiation. With their help, it is possible to suppress
adverse effects, especially of gamma and beta radiation and neutrons originating from artificial and natural
radionuclides and from cosmic radiation, without the use of lead or other metallic materials. These building
materials and components with a specific weight of about 2.4 g/cm3 allow the construction of shielding
objects of different geometries, the optimization of the number of block layers and the construction of even
very large shielding objects and low-background rooms, where the use of lead is impossible due to price
or for other reasons. This results in a simple, cheap, environmentally-friendly and efficient reduction of
background radiation for the purposes of research, experimental, medical, metrological and technological
objects. A special advantage is the possibility of construction of shielding cells, where the detector assembly
can be freely positioned in place of lead shielding structures firmly attached to the detector assembly. This
allows even the placement of multiple detector assemblies inside the object and their simple transportability.
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