Cross-talk limits of monolithic highly-segmented semiconductor detectors for high-resolution X-gamma spectrometry are investigated. Cross-talk causes false signal components yielding amplitude losses and fold-dependent shifts of the spectral lines, which partially spoil the spectroscopic performance of the detector. Two complementary electrical models are developed, which describe quantitatively the interchannel cross-talk of monolithic segmented detectors whose electrodes are read out by charge-sensitive preamplifiers. The first is here designated as Cross-Capacitance (CC) model, the second as Split-Charge (SC) model. The CC model builds around the parasitic capacitances Cij linking the preamplifier outputs and the neighbor channel inputs. The SC model builds around the finite-value of the decoupling capacitance CC used to read out the high-voltage detector electrode. The key parameters of the models are individuated and ideas are shown to minimize their impact. Using a quasi-coaxial germanium segmented detector it is found that the SC cross-talk becomes negligible for decoupling capacitances larger than 1 nF, where instead the CC cross-talk tends to dominate. The residual cross-talk may be reduced by minimization of stray capacitances Cij, through a careful design of the layout of the Printed Circuit Board (PCB) where the input transistors are mounted. Cij can be made as low as ~5 fF, but it is shown that even in such case the impact of the CC cross-talk on the detector performance is not negligible. Finally, an algorithm for cross-talk correction is presented and elaborated.
Cross-talk limits of highly segmented semiconductor detectors / A. Pullia, D. Weisshaar, F. Zocca, D. Bazzacco - In: 2009 IEEE Nuclear science symposium conference record : October 25–31, 2009 : Orlando, Florida, USA / [a cura di] B. Yu. - Piscataway : IEEE, 2009. - ISBN 9781424439614. - pp. 1707-1711 (( convegno Nuclear science symposium and medical imaging conference tenutosi a Orlando nel 2009.
|Titolo:||Cross-talk limits of highly segmented semiconductor detectors|
PULLIA, ALBERTO (Primo)
|Parole Chiave:||nuclear electronics; semiconductor detectors; X-ray spectrometers|
|Settore Scientifico Disciplinare:||Settore ING-INF/01 - Elettronica|
Settore FIS/01 - Fisica Sperimentale
Settore FIS/04 - Fisica Nucleare e Subnucleare
|Data di pubblicazione:||2009|
|Enti collegati al convegno:||Institute of Electrical and Electronics Engineers (IEEE)|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1109/NSSMIC.2009.5402224|
|Tipologia:||Book Part (author)|
|Appare nelle tipologie:||03 - Contributo in volume|