| 摘要 |
<p>An amplification degree stabilizer for photomultiplier tubes (hereinafter referred to as PMT's) in a radioactive ray position detector which is constituted by a scintillator and a plurality of PMT's. The neighboring PMT's (3) are so grouped as to belong to different groups (A to D), and outputs of the PMT's (3) are added up together through adders (6) for each of the groups. The added signal of the group belonging to a PMT which is determined to be closest to a point of emitting light is analyzed for its crest value by a crest analyzer (14). Results of analysis of crest values are collected by a counter memory (data collecting means) (15), i.e., changes in the amplification degrees of the PMT's are collected as statistic data. Relying upon the statistic data, contents of a register (17) which stores the data related to high voltages to be applied to the PMT's (3) are corrected by a data processing circuit (16). According to the above amplification degree stabilizer for the PMT's, the data related to amplification degree of the PMT's are collected in parallel, thus making it possible to stabilize the amplification degree of the PMT's (3) within short periods of time.</p> |
