The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) , composed of two small satellites, is a new mission to monitor the Gamma-Ray Bursts (GRBs) coincident with Gravitational Wave (GW) events with a FOV of 100% all-sky.Each GECAM satellite detects and localizes GRBs using 25 compact and novel Gamma-Ray Detectors (GRDs) in 6 keV-5 MeV. Each GRD module is comprised of LaBr3:Ce scintillator, SiPM array and preamplifier. A large dynamic range of GRD is achieved by the high gain and low gain channels of the preamplifier. The energy response of GRD prototype was evaluated using radioactive sources in the range of 5.9-1332.5 keV. A energy resolution of 5.3% at 662 keV was determined from the 137Cs pulse height spectra, which meets the GECAM requirement (< 8% at 662 keV). Energy to channel conversion was evaluated and a nonlinearity correction was performed to reduce the residuals (< 1.5%). Also, a Geant4-based simulated in-flight background and a measured GRD LaBr3:Ce intrinsic activity were used to evaluate the capability of in-flight calibration. These results demonstrate the design of GRD.
As a new member of GECAM mission, the GECAM-C (also called High Energy Burst Searcher, HEBS) is a gamma-ray all-sky monitor onboard SATech-01 satellite, which was launched on July 27th, 2022 to detect gamma-ray transients from 6 keV to 6 MeV, such as Gamma-Ray Bursts (GRBs), high energy counterpart of Gravitational Waves (GWs) and Fast Radio Bursts (FRBs), and Soft Gamma-ray Repeaters (SGRs). Together with GECAM-A and GECAM-B launched in December 2020, GECAM-C will greatly improve the monitoring coverage, localization, as well as temporal and spectral measurements of gamma-ray transients. GECA…
The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) satellite consists of two small satellites. Each GECAM payload contains 25 gamma ray detectors (GRD) and 8 charged particle detectors (CPD). GRD is the main detector which can detect gamma-rays and particles and localize the Gamma-Ray Bursts (GRB),while CPD is used to help GRD to discriminate gamma-ray bursts and charged particle bursts. The GRD makes use of lanthanum bromide (LaBr3) crystal readout by SiPM. As the all available SiPM devices belong to commercial grade, quality assurance tests need to be perf…
Each satellite of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM, mission) consists of 25 SiPM based gamma-ray detectors (GRDs). Although SiPM based GRD has merits of compact size and low bias-voltage, the drift of the SiPM gain with temperature is a severe problem for GRD performance. An adaptive voltage supply source was designed to automatically adjust the SiPM bias voltage to compensate the temperature effects and keep the gain stable. This approach has been proved to be effective during both the on-ground and in-flight tests. The in-flight measured v…
The GECAM mission consists of two identical microsatellites (GECAM-A and GECAM-B). Each satellite is equipped with 25 gamma-ray detectors (GRD) and 8 charged particle detectors (CPD). The main scientific objective of the GECAM mission is to detect gamma-ray bursts (GRBs) associated with the gravitational wave events produced by the merging of binary compact stars. After the launch on Dec. 10, 2020 , we carried out a series of on orbit tests. This paper introduces the test results of the GECAM-B satellite. According to the in-flight performance, the energy band for gamma-ray detection of GECAM-…
The main scientific goal of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is to monitor various types of Gamma-Ray Bursts (GRB) originated from merger of binary compact stars, which could also produce gravitational wave, and collapse of massive stars. In order to study the response of GECAM Gamma-Ray Detectors (GRDs) to high-energy bursts and test the in-flight trigger and localization software of GECAM before the launch, a portable GRB simulator device is designed and implemented based on grid controlled X-ray tube (GCXT) and direct digital synthesis (…
The Gravitational Wave highly energetic Electromagnetic Counterpart All-sky Monitor (GECAM) is dedicated to detecting gravitational wave gamma-ray bursts. It is capable of all-sky monitoring over and discovering gamma-ray bursts and new radiation phenomena. GECAM consists of two microsatellites, each equipped with 8 charged particle detectors (CPDs) and 25 gamma-ray detectors (GRDs). The CPD is used to measure charged particles in the space environment, monitor energy and flow intensity changes, and identify between gamma-ray bursts and space charged particle events in conjunction with GRD. CP…
Performance Evaluation of a High-Granularity LYSO-SiPM-Based Position-Sensitive Detector for a One-Shot Gamma-Scanning System with Sub-Millimeter Spatial Resolution
Indian Institute of Technology Ropar（印度技术研究所罗帕尔分校）；Gauhati University（高哈提大学）；GSI Helmholtzzentrum für Schwerionenforschung（GSI亥姆霍兹重离子研究中心）；Istanbul University（伊斯坦布尔大学）
CLLBC(Ce) and TLYC(Ce) are novel scintillation materials capable of measuring mixed gamma ray and neutron radiation fields that have gained significant interest in the areas of space and nuclear safety/security science. To date Geant4, the world's most popular Monte Carlo radiation modelling toolkit, has yet to be effectively used to simulate the full response of these materials when coupled to near ultra-violet Silicon PhotoMultipliers (SiPMs). In this work an experimentally validated Geant4 application has been developed with optimised material composition, optical data tables, and physics t…
Iterative reconstruction of SiPM light response functions in a square-shaped compact gamma camera
具有正方形单片闪烁体晶体和硅光电倍增器（SiPM）阵列的紧凑型伽马相机正在积极地开发用于诸如小动物成像、癌症诊断和放射性示踪剂引导的外科手术的领域中的应用。位置重建的统计方法，这是潜在的优于传统的质心方法，需要准确的知识，每个光电倍增管的空间响应。使用两个蒙特卡罗模拟和实验数据获得的相机原型，我们表明，所有的光电倍增管（光响应函数）的空间响应可以参数化与轴对称函数迭代获得的洪水场照射数据。该研究使用配备有30 x 30 x 2 mm3 LYSO晶体和8 x 8 SiPM阵列的相机原型进行，用于140 keV伽马射线。模拟表明，使用迭代方法获得的响应，用极大似然方法重建的图像仅表现出微小的失真：在22 x 22 mm 2的中心区域，X和Y方向上重建的位置与真实位置之间的平均差异不超过0.2 mm，在相机的外围不超过0.4 mm。一个类似的水平的图像失真的实验与相机原型。
Large-area silicon photomultipliers (SiPMs) are desired in many applications where large surfaces have to be covered. For instance, a large area SiPM has been developed by Hamamatsu Photonics in collaboration with the University of Geneva, to equip gamma-ray cameras employed in imaging atmospheric Cherenkov telescopes. Being the sensor about 1 cm$^2$, a suitable preamplification electronics has been investigated in this work, which can deal with long pulses induced by the large capacitance of the sensor. The so-called Multiple Use SiPM Integrated Circuit (MUSIC), developed by the ICCUB (Univer…
Gamma-ray emission from special nuclear material (SNM) is relatively easy to shield from detection using modest amounts of high-Z material. In contrast, fast-neutrons are much more penetrating and can escape relatively thick high-Z shielding without losing significant energy. Furthermore, fast neutrons provide a clear and unambiguous signature of the presence of SNM with few competing natural background sources. The challenge of detecting fast neutrons is twofold. First, the neutron flux from SNM are only a fraction of the corresponding gamma-ray flux. Second, fast neutrons can be difficult to…
Compact X-rays detectors made of 1/2" or 1" :LaBr3:Ce crystals of cubic shape with SiPM array readout have been developed for the FAMU experiment at RIKEN-RAL. The aim is a precise measurement of the proton Zemach radius with incoming muons. Additional applications may be found in medical physics, such as PET, homeland security and gamma-ray astronomy. Due to the high photon yield of LaBr3:Ce it was possible to use a simple readout scheme based on CAEN V1730 digitizers. Detectors, using Hamamatsu S13361 or S14161 arrays, have good FWHM energy resolutions up to 3 % (8 %) at the Cs137 Co57) peak…
Plastic scintillation detectors represent an efficient, cost-effective, customizable solution for assessment of gamma radiation fields in the context of nuclear security, environmental radiation survey, radiological and nuclear incidents response (RNe) and dosimetry for radiation protection purposes. Solid state light readout technologies such as Silicon Photomultiplier diodes (SiPM) are characterized by low operational voltage, mechanical robustness, compact dimensions, and fast pulse rise-time. Due to these intrinsic advantages, Silicon Photomultiplier diodes have been progressively replacin…
Recently, silicon photomultipliers (SiPMs) have been used in several space-borne missions, owing to their solid state, compact size, low operating voltage, and insensitivity to magnetic fields. However, operating SiPMs in space results in radiation damage and degraded performance. In-orbit quantitative studies on these effects are limited. In this study, we present in-orbit SiPM characterization results obtained by the second detector of the Gamma-Ray Integrated Detectors (GRID-02), which was launched on 6 November 2020. An increase in dark current of $\sim$100 $μ$A/year per SiPM chip (model M…
LaB$_3$:Ce crystals have been introduced for radiation imaging in medical physics, with photomultiplier or single SiPM readout. An R-D was pursued with 1/2" and 1" LaBr3:Ce crystals, from different producers, to realize compact large area detectors (up to some cm$^2$ area) with SiPM array readout, aiming at high light yields, good energy resolution, good detector linearity and fast time response for low-energy X-rays. A natural application was found inside the FAMU project at RIKEN-RAL muon facility, that aims at a precise measure of the proton Zemach radius to solve the so-called "proton radi…
Over the last decade one of the most significant technological advances made in the field of radiation detectors for nuclear medicine was the development of Silicon Photomultipler (SiPM) sensors. At present a only small number of SiPM based radiation detectors for Single Photon Emission Computed Tomography (SPECT) applications have been explored, and even fewer experimental prototypes developed. An in-silico investigation into the optimal design of a Philips DPC3200 SiPM photosensor-based thin monolithic scintillator detector for SPECT applications was undertaken using the Monte Carlo radiatio…
Radiation damage of J-series silicon photomultipliers (SiPMs) has been studied in the context of using these photodetectors in future space-borne scintillation detectors. Several SiPM samples were exposed to 101.4 MeV protons, with 1 MeV neutron equivalent fluence ranging from 1.27*10^8 n/cm^2 to 1.23*10^10 n/cm^2 . After the irradiation, the SiPMs experienced a large increase in the dark current and noise, which may pose problems for long-running space missions in terms of power consumption, thermal control and detection of low-energy events. Measurements performed with a CeBr3 scintillator c…
Performance of FBK VUV-HD3 and HPK VUV4 SiPMs in the Light-only Liquid Xenon (LoLX) Detector
Simon Fraser University（西蒙菲莎大学）；McGill University（麦吉尔大学）；Queen's University（女王大学）；The University of British Columbia（不列颠哥伦比亚大学）；Drexel University（德雷塞尔大学）；Obafemi Awolowo University（奥巴费米·阿沃洛沃大学）
Development of a CsI:Tl calorimeter subsystem for the All-Sky Medium-Energy Gamma-Ray Observatory (AMEGO)
我们报告了全天空中能伽马射线天文台（AMEGO）的掺铊碘化铯（CsI：Tl）量热仪子系统的发展[1]。CsI：Tl量热计是AMEGO仪器套件的三个主要子系统之一;其他子系统包括双面硅条探测器（DSSD）跟踪器/转换器和碲锌镉（CZT）量热计。与费米伽马射线太空望远镜上的LAT仪器类似，速端量热计由正交分层的CsI：Tl棒组成。与使用PIN光电二极管的LAT不同，CsI：Tl棒两端的闪烁光是用最近开发的大面积硅光电倍增器（SiPM）阵列读出的。目前正在美国航天局APRA方案的资助下，为一个大型空间γ射线观测站开发热量计技术。根据该计划，我们已经设计，建造并正在测试一个由24个CsI：Tl棒（每个尺寸为16.7 mm x 16.7 mm x 100 mm）组成的原型，该原型以hodoscopically排列在四层中，每层六个棒。每个条的末端用SensL ArrayJ quad SiPM读出。信号读出和处理由IDEAS SIPHRA（IDE 3380）ASIC完成。该原型的性能测试是在实验室源和初始波束测试中完成的;未来的测试和表征将在第二次波束测试（2019年）和气球飞行（2020年）期间与NASA-GSFC领导的其他子系统一起完成。我们将讨论最初的校准测试，原型的建设和最新的结果，从实验室和光束测试与模拟/数字电子和SIPHRA DAQ。
Aiming to measure the difference in arrival times of two coincident gamma-photons with an accuracy in the order of 200 ps, time-of-flight positron emission tomography systems commonly employ silicon photomultipliers (SiPMs) and high-resolution digitization electronics, application specific integrated circuits (ASICs). This work evaluates the performance of the TOFPET2 ASIC, released by PETsys Electronics S.A. in 2017, dependent on its configuration parameters in multi-channel coincidence measurements. SiPM arrays fabricated by different vendors (KETEK, SensL, Hamamatsu, Broadcom) were tested i…
POLAR-2 is a space-borne polarimeter, built to investigate the polarization of Gamma-Ray Bursts and help elucidate their mechanisms. The instrument is targeted for launch in 2024 or 2025 aboard the China Space Station and is being developed by a collaboration between institutes from Switzerland, Germany, Poland and China. The instrument will orbit at altitudes between 340km and 450km with an inclination of 42$^{\circ}$ and will be subjected to background radiation from cosmic rays and solar events. It is therefore pertinent to better understand the performance of sensitive devices under space-…
