| 摘要 |
An automatic calibration system corrects for photomultiplier drift while the gamma camera is in imaging mode. The known constant energy from the gamma rays producing scintillated light is used to effect the drift adjustment by weighting the position signals of the scintillations to determine if a valid event has occurred and building, for each photomultiplier in the camera, a statistically valid, spectral energy histogram. When the histogram counts reach a sufficient sample size the histogram data is read out in a discriminatory manner to account for noise and Compton scattering effects and used to either directly adjust the photomultiplier gain or the calibration look up tables depending on what type of system is used by the camera to process the photomultiplier signals.
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