NUKLEONIKA 2004, 49(3):115-121

LARGE SAMPLE NEUTRON ACTIVATION ANALYSIS: CORRECTION FOR NEUTRON AND GAMMA ATTENUATION

Faidra Tzika1,2, Ion E. Stamatelatos1, John Kalef-Ezra2, Peter Bode3

1 Institute of Nuclear Technology and Radiation Protection, NCSR “Demokritos”, 15310 Aghia Paraskevi Attikis, Greece,
2 Medical Physics Laboratory, Medical School, University of Ioannina, 45110 Ioannina, Greece,
3 Interfaculty Research Institute, Delft University of Technology, 15 Mekelweg, 2629 JB Delft, The Netherlands


A Large Sample Neutron Activation Analysis (LSNAA) facility is under development at the GRR-1 research reactor, NCSR “Demokritos”. The LSNAA facility design incorporates sample irradiation in the reactor graphite thermal neutron column and subsequent measurement of the activity induced in a gamma spectroscopy system with gamma ray transmission measurement options included. The Monte Carlo neutron and photon transport code MCNP-4C was used to model the facility. Appropriate correction factors accounting for neutron field perturbation during sample irradiation and high-purity germanium detector efficiency for the volume source were derived. The results of the computations were experimentally verified by measurements for a set of known materials. The LSNAA facility will be used to perform multi-element, non-destructive, contamination-free analysis of large volume samples with high sensitivity and excellent sampling. End-users of the facility will be archaeological, environmental, bio-medical research laboratories and industry.