
7.3 Detection of Threat Materials (Explosives, Drugs, and Dangerous Chemicals)
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3. Arsenic trioxide of mass 2kg. Measurement time 7000 s, 24 × 10
7
emit-
ted tagged Neutrons. Arsenic gamma lines are marked.
4. Teon of mass 1 kg. Measurement time 10,026 s, 36 × 107 emitted
tagged neutrons.
e background spectra indicated in black are obtained for the same experi-
mental conditions with the target out.
e source of the background can be also the sediments on which the object
is placed on the bottom of the sea or riverbed. ey have shown that the gamma
ray spectra obtained from the measurements of the sediments are dominated
by lines of si