Abstract: A pulse pile-up discrimination system for a multicell detector accumulates a charge on each cell to detect its response to a radiant emission impinging on an unknown position of the detector; the position of impingement of the radiant emission is established in accordance with the charge on each cell; a pulse pile-up discriminator provides, associated with each impingement position, lower and upper discrimination levels of a function of the distribution of charge on the cells indicative of a pulse pile-up; a function of the distribution of the charge on the cells is generated in response to the radiant emission impinging on the unknown position of the detector; the function of the distribution of charges on the cells in response to the radiant emission impinging on the unknown position of the detectors is compared to the lower and upper discrimination levels of a function of the distribution of charges provided by the pulse pile-up discriminator to determine whether a pulse pile-up has occurred.

Abstract: Digital calibration and position analysis of impingement of a radiant emission on a multi-cell detector for calibration, including: directing radiant emissions to the multi-cell detector from a number of known origin positions and for each radiant emission from each origin position sampling the response of each cell, converting from analog to digital form the amplitude response of each cell; normalizing the digitized amplitude response of each cell; averaging the normalized digital amplitude response of each cell; determining from the average normalized digitized amplitude response and normalized digitized amplitude responses of each cell, the standard deviation value for each cell and the slope of the amplitude response of each cell; determining from the ratio of the slope and deviation values a weighting factor for the uncertainty of response of each cell at each origin position; determining with respect to each cell whether the origin position is to the left or right of that cell; and storing in one of a r