Beatrice Pedretti;Giacomo Borghi;Giacomo Ticchi;Davide Di Vita;Marco Carminati;Carlo Fiorini
{"title":"Charge Sharing Assessment and Active Collimation in Monolithic Arrays of Silicon Drift Detectors","authors":"Beatrice Pedretti;Giacomo Borghi;Giacomo Ticchi;Davide Di Vita;Marco Carminati;Carlo Fiorini","doi":"10.1109/TNS.2024.3429622","DOIUrl":null,"url":null,"abstract":"Charge sharing (CS) between pixels is a significant concern in X-ray spectroscopy detectors based on monolithic arrays of silicon drift detectors (SDDs) when a photon is absorbed near a pixel edge. Traditional mechanical collimation mitigates CS but decreases the active area of the detector. This is particularly true for small-pixel detectors, where the mechanical collimator shields a significant portion of the active area and, moreover, becomes quite complex to be manufactured for small apertures. In this work, we carry out a study of CS in SDDs and introduce active collimation as an alternative to mechanical collimation, leveraging key parameters of signals at the output of the charge-sensitive amplifier (CSA), to identify CS events occurring within a defined coincidence window (CW) in neighboring pixels. To validate the technique, we first conducted a quantitative assessment of the impact of CS on a 16-element monolithic SDD module with 2-mm-side square pixels using a focused pulsed laser. We then tested an active collimation algorithm on this detector configuration during a spectroscopic measurement with an uncollimated 55Fe source, demonstrating its capability in recovering CS events and reconstructing them as Mn-K\n<inline-formula> <tex-math>$\\alpha $ </tex-math></inline-formula>\n peak events. This active collimation approach, in contrast to mechanical collimation, not only enhances the effective active area while achieving a substantial reduction in the background continuum of the spectrum, but also recovers information inevitably lost in uncollimated detectors due to intrinsic CS effects.","PeriodicalId":13406,"journal":{"name":"IEEE Transactions on Nuclear Science","volume":"71 10","pages":"2287-2296"},"PeriodicalIF":1.9000,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10604722","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Transactions on Nuclear Science","FirstCategoryId":"5","ListUrlMain":"https://ieeexplore.ieee.org/document/10604722/","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
Charge sharing (CS) between pixels is a significant concern in X-ray spectroscopy detectors based on monolithic arrays of silicon drift detectors (SDDs) when a photon is absorbed near a pixel edge. Traditional mechanical collimation mitigates CS but decreases the active area of the detector. This is particularly true for small-pixel detectors, where the mechanical collimator shields a significant portion of the active area and, moreover, becomes quite complex to be manufactured for small apertures. In this work, we carry out a study of CS in SDDs and introduce active collimation as an alternative to mechanical collimation, leveraging key parameters of signals at the output of the charge-sensitive amplifier (CSA), to identify CS events occurring within a defined coincidence window (CW) in neighboring pixels. To validate the technique, we first conducted a quantitative assessment of the impact of CS on a 16-element monolithic SDD module with 2-mm-side square pixels using a focused pulsed laser. We then tested an active collimation algorithm on this detector configuration during a spectroscopic measurement with an uncollimated 55Fe source, demonstrating its capability in recovering CS events and reconstructing them as Mn-K
$\alpha $
peak events. This active collimation approach, in contrast to mechanical collimation, not only enhances the effective active area while achieving a substantial reduction in the background continuum of the spectrum, but also recovers information inevitably lost in uncollimated detectors due to intrinsic CS effects.
期刊介绍:
The IEEE Transactions on Nuclear Science is a publication of the IEEE Nuclear and Plasma Sciences Society. It is viewed as the primary source of technical information in many of the areas it covers. As judged by JCR impact factor, TNS consistently ranks in the top five journals in the category of Nuclear Science & Technology. It has one of the higher immediacy indices, indicating that the information it publishes is viewed as timely, and has a relatively long citation half-life, indicating that the published information also is viewed as valuable for a number of years.
The IEEE Transactions on Nuclear Science is published bimonthly. Its scope includes all aspects of the theory and application of nuclear science and engineering. It focuses on instrumentation for the detection and measurement of ionizing radiation; particle accelerators and their controls; nuclear medicine and its application; effects of radiation on materials, components, and systems; reactor instrumentation and controls; and measurement of radiation in space.