Sensitive measurements of the trace elements require the use of an active s
uppression of the overall detection background. For this reason, an anticom
pton system made of NaI and HPGe has been constructed at the new undergroun
d laboratory in Garching near Munich for analysis of irradiated samples. Si
gnificantly improved limits for trace elements' concentration in nylon have
been obtained. A suppression factor of 16 in the energy region of 100-400
keV was reached. (C) 2000 Elsevier Science Ltd. All rights reserved.