| 摘要 |
<p>PURPOSE: To simplify the circuitry by providing first scintillator having first and second ends, second scintillator having arranged first and second ends, means for establishing a thermal gradient. CONSTITUTION: A scintillator strip has first and second terminals 2A, 4A and 2B, 4B arranged such that all first terminals 2A, 4A define the first side 16 of a region while all second terminals 2B, 4B define the second side 18 of region. The region is normal to the incident direction of incoming gamma radiation. The scintillator strips 2, 4,..., 12 form three pairs in which one pair includes an NaI strip 2B and a CsI strip 4, for example. Each strip in each pair is coupled optically at one end thereof through a small optical pipe and also coupled with an avalanche photodiode. Six strips are entirely coupled optically with a photomultiplier 38 having an output end 40 connected with an attenuation time evaluation circuit 42.</p> |
