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It is described the global architecture of a digital pulse processing system for high resolution X-Ray spectroscopy based on single photon detection and photon energy measurement. The core of the system is implemented in a modern hybrid device (Xilinx Zynq) that integrates an FPGA fabric along with a dual core 32-bits processor (ARM Cortex). It is also described the adopted strategy to deal with high...
Components of complex dielectric permittivity of semi-insulating Cd1−xZnxTe crystals had been measured in the dark and under photo excitation. Also we studied energy resolution of radiation detectors made from these crystals for 137Cs quants. Present studies have been carried out taking into account using specimens from different regions of crystal ingot. It is ascertained that investigated values...
The overall trend in calorimetry is towards high granularity, both laterally and longitudinally. This trend is a requirement for the full exploitation of the Particle Flow Algorithms, which reconstruct individual particles using the sub-detector that provides the best resolution for this specific particle. The increased level of detail in the event topologies due to higher segmentation of the calorimeter...
In PET systems with a geometry different from a closed ring, the Time of Flight (TOF) of the annihilation photons appears to be relevant. Such a system capability helps to compensate the missing angular information that generates artifacts on the reconstructed images. In this work, two ASIC designs are evaluated for their use in PET systems having accurate coincidence resolving times (CRT) while preserving...
A novel single-ended-readout depth-of-interaction (DOI) detector is proposed for application in positron emission tomography (PET). The crystal unit of this detector is formed by a transform of the crystal unit of a dual-ended readout detector, which is constructed from a LYSO scintillator pillar segmented using sub-surface laser engraving (SSLE). Specifically, two scintillator pillars are coupled...
We previously built a high-resolution PET scanner (PawPET) using 8 mm thick Lutetium Oxyorthosilicate (LSO) detectors, but it suffers from poor sensitivity. From our prior work we know that unpolished 0.5 mm pitch arrays with Toray reflector are challenging to decode at depths greater than 8 mm. We hypothesize that decoding will improve by polishing the crystal surfaces. We also know that polished...
We are developing a PET detector capable of measuring both time-of-fight (TOF) and depth-of-interaction (DOI) with a goal to improve resulting image quality and accuracy. Phoswich designs have been realized in PET detectors to measure DOI for more than a decade. However, PET detectors based on phoswich designs put great demand on the readout circuit, which has to differentiate the pulse shape produced...
The High Granularity Calorimeter (HGCAL) is the technology choice of the CMS collaboration for the endcap calorimetry upgrade planned to cope with the harsh radiation and unprecedented in-time event pileup projected at the High Luminosity-LHC era. In this context, profiting from fast-timing information with a resolution of a few tens of picoseconds embedded in the calorimeter would represent a unique...
A cadmium zinc telluride (CZT) based small animal positron emission tomography (PET) system is under development at the Molecular Imaging Instrumentation Laboratory (MIIL) at Stanford University (Fig. 1) [1,2]. A goal for this system is to advance the ability to detect, visualize, and quantify low concentration of molecular probes. Key technologies of this work are: (1) CZT detector technology, instead...
PET is the most sensitive imaging technique in the field of nuclear medicine. However, the single count rate is typically 10 times higher than the coincidence count rate. This means that there are a lot of pairs of undetected annihilation photons. For single gamma imaging, Compton imaging is known as the only method to obtain directional information of an incoming gamma ray without using collimators...
Trapezoidal shaping algorithm is widely used in the measurement of nuclear signal and spectroscopy, which contributes to reduce pile-up effect and achieve good resolution. In order to take into account the environmental noise and get high signal-to-noise ratio for dedicated systems, the Digital Penalized Least Mean Squares (DPLMS) method is employed to calculate optimum digital FIR filters. Implemented...
Many applications require the generation of gamma spectra at event rates in excess of 106 s−1 as well as very good energy resolution, e.g., safeguards, emergency response, and nondestructive assay. Good energy resolution is especially important when lower activity isotopes are sought among a large background (or foreground) that would otherwise dominate the spectrum, such as the minor actinides present...
We are developing a time-of-flight (TOF) positron emission tomography (PET) scanner for brain imaging using SiPMs. In our development, we have adopted a strip-line based signal multiplexing method for efficient channel reduction for SiPMs; the method is using a single strip-line on which multiple SiPMs are connected for sharing readout, and the position of hit SiPM is decoded from the arrival time...
Spatial resolution is one of the most important performance in PET system. Higher spatial resolution can give more information about the region of interest in animal PET imaging. In this work, we implement a high resolution (approximate 0.7 mm) all digital animal PET system using improved Trans-PET detectors. The improved detector module uses 24×24 crystal array for higher intrinsic spatial resolution...
PET systems are widely used in clinical and preclinical molecular imaging applications. Various PET systems, including whole-body human and small animal PET, and dedicated systems such as breast and brain PET have been developed. A Standardized PET detector module with good performance will make it much easier and more efficient for different kind of PET scanner instrumentation. In this paper, we...
Gamma-imaging system is of great interest to monitor the contamination of radioactive substances in a wide range of areas at nuclear power plants. The purpose of this study was to develop a compact gamma camera capable of detecting and imaging the radioactive sources present in contaminated area. The prototype of compact gamma camera with 73 × 99 mm2 FOV was composed of pinhole collimator, SiPM based...
This paper presents the performances of the ME100 detector under monochromatic photon beam at various fluence rates. The ME100 is a multi-channel high count rate x-ray spectrometric detector commercialized by Multix Detection (Moirans, France). Measurements were performed at the European Synchrotron Radiation Facility and at Multix Detection facility. Detector energy resolution, linearity and stability...
We introduce a compact preclinical PET detector that combines the output from 64 SiPM channels, forming an 8×8 matrix of pixels capable of efficiently encoding event position, with good energy and time resolution, as well as depth of interaction information. The scintillator matrices used to characterize the detector are a 16×16 matrix comprised of 1.3×1.3×12mm3 LYSO crystals, and a 1.3×1.3×15mm3...
A whole-body PET device is sometimes not suitable for brain studies because the achieved image resolution is typically not sufficient to investigate small size structures. Thus, a dedicated brain PET insert system with high performance would overcome such limitations. Moreover, these functional studies lack of anatomical information. It is shown elsewhere the convenience of simultaneously acquisition...
In this work the experimental results are presented showing the spectroscopic performance of the ASIC multichannel charge-sensitive preamplifier of TRACE (TRacking Array for light Charged particle Ejectiles). The results were obtained connecting a silicon pad detector to a custom-designed preamplifier board with eight ASIC CSPs. The detector and the board were put in a vacuum chamber with a triple...
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