PHOTOMULTIPLIER

摘要

PROBLEM TO BE SOLVED: To easily stabilize a gain rate in response to temperature variation.SOLUTION: When a gamma camera of a SPECT device is constituted by a SiPM (Silicon Photomultiplier), all APDs (Avalanche Photodiodes) 14c possessed by the SiPM are classified into APD arrays 14d consisting of a predetermined number of APDs 14c. A voltage control mechanism is installed for each APD array 14d. The voltage control mechanism includes a semiconductor resistor 14e whose resistance value decreases in response to increase in ambient temperature and increases in response to decrease in ambient temperature, and a fixed resistor 14f that is connected to the semiconductor resistor 14e in series and whose resistance value is fixed against variation in ambient temperature. The fixed resistor 14f is connected to each APD 14c of the APD array 14d in parallel.