TESTS OF INSTRUMENTS FOR NEUTRON AND GAMMA-RAY MEASUREMENTS AT SEVERAL RADIONUCLIDE NEUTRON SOURCES

Neutron radiation protection instruments have been tested and gamma ra y field characteristics have been studied for several radionuclide neu tron sources (Am-Li, Am-F, Am-Be, Pu-Be, Cf, and Cf/D2O/Cd) of differe nt construction available at two laboratories. Several active (TEPC, m oderator-type rem meters, scintillator- and GM-based dose rate meters, Si- and GM-based individual electronic dosemeters) and passive detect ors (TLDs, bubble) have been used. Particular attention has been paid to the contribution of the gamma component to the total dose equivalen t. The influence of Pb shielding of the sources has been characterised for all sources mentioned above, our values are generally a little lo wer than some of those recommended in the literature. The present stud ies also revealed the importance of particular features of some of the devices used (sensitivity to fast neutrons of some photon detectors, overestimation of high energy photons).