TY  - JOUR
A1  - Streun, M.
A1  - Christ, D.
A1  - Hellendung, A.
A1  - Larue, H.
A1  - Ziemons, Karl
A1  - Halling, H.
T1  - Effects of crosstalk and gain nonuniformity using multichannel PMTs in the Clearpet® scanner
JF  - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
N2  - The ClearPET® scanners developed by the Crystal Clear Collaboration use multichannel PMTs as photodetectors with scintillator pixels coupled individually to each channel. In order to localize an event each channel anode is connected to a comparator that triggers when the anode signal exceeds a common predefined threshold. Two major difficulties here are crosstalk of light and the gain nonuniformity of the PMT channels. Crosstalk can generate false triggering in channels adjacent to the actual event. On the one hand this can be suppressed by sufficiently increasing the threshold, but on the other hand a threshold too high can already prevent valid events on the lower gain channels from being detected. Finally, both effects restrict the dynamic range of pulse heights that can be processed. The requirements to the dynamic range are not low as the ClearPET® scanners detect the depth of interaction by phoswich pixels consisting of LSO and Lu0.7Y0.3AP, two scintillators with different light yields. We will present a model to estimate the achievable dynamic range and show solutions to increase it.
Y1  - 2005
SN  - 0168-9002
N1  - Proceedings of the 7th International Conference on Inorganic Scintillators and their Use in Scientific and Industrial Applications
VL  - 537
IS  - 1-2
SP  - 402
EP  - 405
ER  -