Patent ID: 8193507

Claim:
A system for compensating for a gain non-uniformity of Multi-anode Position Sensitive Photomultiplier Tube (PS-PMT), the system comprising: the PS-PMT ( 200 ) configured to convert scintillation, generated by gamma rays incident to specific scintillation crystals ( 100 ), into electrons, amplify the electrons on a channel basis, and output current signals through a number of respective channels; a position detection circuit unit ( 300 ) configured to compress the current signals into four current signals and dividedly output the four current signals in order to display gamma-ray interaction positions on the scintillation crystals ( 100 ) in a form of a 2-dimensional energy distribution based on the current signals; a compensation unit ( 400 ) configured to comprise a serial variable resistor ( 410 ) and a parallel variable resistor ( 420 ), connected between an output port of each of the channels and an input port of the position detection circuit unit ( 300 ), corresponding to the each channel, and to compensate for intensities of the input current signals inputted to the input ports of the position detection circuit unit ( 300 ) by changing resistance values of at least one of the serial variable resistors ( 410 ) and the parallel variable resistors ( 420 ); and a coordinate calculation unit ( 500 ) configured to receive the divided and outputted four current signals based on the input current signals with the compensated intensities and to calculate coordinates of the gamma-ray interaction positions based on the received four current signals.