Search results for "Charge sharing"

Digital performance improvements of a CdTe pixel detector for high flux energy-resolved X-ray imaging

2015

Abstract Photon counting detectors with energy resolving capabilities are desired for high flux X-ray imaging. In this work, we present the performance of a pixelated Schottky Al/p-CdTe/Pt detector (4×4) coupled to a custom-designed digital readout electronics for high flux measurements. The detector (4×4×2 mm 3 ) has an anode layout based on an array of 16 pixels with a geometric pitch of 1 mm (pixel size of 0.6 mm). The 4-channel readout electronics is able to continuously digitize and process the signals from each pixel, performing multi-parameter analysis (event arrival time, pulse shape, pulse height, pulse time width, etc.) even at high fluxes and at different throughput and energy re…

Charge loss correction in CZT pixel detectors at low and high fluxes: analysis of positive and negative pulses

2018

Charge losses are typical drawbacks in cadmium–zinc–telluride (CZT) pixel detectors. The effects of these phenomena are strongly related to the interaction point of the photons and are more severe for photon interactions at the inter-pixel gap and near the pixelated anode. In this work, we present some original techniques able to correct charge losses in pixelated CZT detectors at both low and high fluxes. The height, the shape and the arrival time of collected- and induced-charge pulses with both positive and negative polarities are analysed to recover charge losses after the application of charge sharing addition (CSA). Sub-millimetre CZT pixel detectors, fabricated by different manufactu…

Digital CZT detector system for high flux energy-resolved X-ray imaging

2017

Photon counting arrays with energy resolving capabilities are recently desired for the next-generation X-ray imaging systems. In this work, we present the performance of a 2 mm thick CZT pixel detector, with pixel pitches of 500 mu m and 250 mu m, coupled to a fast and low noise ASIC (PIXIE ASIC), characterized by only the preamplifier stage. A 16-channel digital readout electronics was used to continuously digitize and process each output channel from the PIXIE ASIC, performing multi-parameter analysis (event arrival time, pulse shape, pulse height) at low and high input counting rates (ICRs). The spectroscopic response of the system to monochromatic X-ray and gamma ray sources, at both lo…

Charge measurement using an array of Faraday’s Cups on a printed circuit board

2014

Abstract An absolute method of measuring charge is to use a Faraday Cup (FC) principle. This study relates to a novel method of measuring charge on a flat substrate, which is coated with charged powder particles. The substrate consists of an array of FC with different dimensions. The sensor is manufactured using flame-retardant printed circuit board (PCB) technology. The objective of this work is to reduce the charge sharing by developing a grounded shield cup around each conductive cup in the array and accordingly increase cup-to-ground capacitance. The results have confirmed that the improved well shielding would provide a more accurate quantitative charge measurement.

A charge reconstruction algorithm for DAMPE silicon microstrip detectors

2019

Abstract The DArk Matter Particle Explorer (DAMPE) can detect electrons and photons from 5 GeV to 10 TeV and charged nuclei from a few tens of GeV to 100 TeV. The silicon–tungstentracker (STK), which is composed of 768 singled-sided silicon microstrip detectors, is one of four subdetectors in DAMPE providing photon conversion , track reconstruction, and charge identification for relativistic charged particles. This paper focuses on the charge identification performance of the STK detector. The charge response depends mainly on the incident angle and the impact position of the incoming particle. To improve the charge resolution, a reconstruction algorithm to correct for these parameters was …

Development of 2D & 3D cadmium–zinc–telluride spectroscopic imagers for X-ray and gamma ray applications

2021

Dual-polarity pulse processing and analysis for charge-loss correction in cadmium–zinc–telluride pixel detectors

2018

Charge losses at the inter-pixel gap are typical drawbacks in cadmium–zinc–telluride (CZT) pixel detectors. In this work, an original technique able to correct charge losses occurring after the application of charge-sharing addition (CSA) is presented. The method, exploiting the strong relation between the energy after CSA and the beam position at the inter-pixel gap, allows the recovery of charge losses and improvements in energy resolution. Sub-millimetre CZT pixel detectors were investigated with both uncollimated radiation sources and collimated synchrotron X-rays, at energies below and above the K-shell absorption energy of the CZT material. The detectors are DC coupled to fast and low…

Energy Recovery of Multiple Charge Sharing Events in Room Temperature Semiconductor Pixel Detectors

2021

Multiple coincidence events from charge-sharing and fluorescent cross-talk are typical drawbacks in room-temperature semiconductor pixel detectors. The mitigation of these distortions in the measured energy spectra, using charge-sharing discrimination (CSD) and charge-sharing addition (CSA) techniques, is always a trade-off between counting efficiency and energy resolution. The energy recovery of multiple coincidence events is still challenging due to the presence of charge losses after CSA. In this work, we will present original techniques able to correct charge losses after CSA even when multiple pixels are involved. Sub-millimeter cadmium–zinc–telluride (CdZnTe or CZT) pixel detectors we…

Charge Sharing and Cross Talk Effects in High-Z and Wide-Bandgap Compound Semiconductor Pixel Detectors

2023

Intense research activities have been made in the development of high-Z and wide-bandgap compound semiconductor pixel detectors for the next generation X-ray and gamma ray spectroscopic imagers. Cadmium telluride (CdTe) and cadmium-zinc-telluride (CdZnTe or CZT) pixel detectors have shown impressive performance in X-ray and gamma ray detection from energies of few keV up to 1 MeV. Charge sharing and cross-talk phenomena represent the typical drawbacks in sub-millimeter pixel detectors, with severe distortions in both energy and spatial resolution. In this chapter, we review the effects of these phenomena on the response of CZT/CdTe pixel detectors, with particular emphasis on the current st…

Single Event Transients and Pulse Quenching Effects in Bandgap Reference Topologies for Space Applications

2016

An architectural performance comparison of bandgap voltage reference variants, designed in a $0.18~\mu \text {m}$ CMOS process, is performed with respect to single event transients. These are commonly induced in microelectronics in the space radiation environment. Heavy ion tests (Silicon, Krypton, Xenon) are used to explore the analog single-event transients and have revealed pulse quenching mechanisms in analogue circuits. The different topologies are compared, in terms of cross-section, pulse duration and pulse amplitude. The measured results, and the explanations behind the findings, reveal important guidelines for designing analog integrated circuits, which are intended for space appli…