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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 (DDS) technologies. The design of this GRB simulator which modulates X-ray flux powered by high voltage up to 20 kV is demonstrated, and the time jitter (FWHM) of the device is about 0.9 $mu$s. Before the launch in December, 2020, both two GECAM satellites were irradiated by different types of GRBs (including short and long bursts in duration) generated by this GRB simulator. The light curves detected with GECAM/GRDs are consistent with the programmed input functions within statistical uncertainties, indicating the good performance of both the GRDs and the GRB simulator.
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 events with a FOV of 100% all-sky. GECAM detects and localizes 6 keV-5 MeV GRBs via 25 compact and novel Gamma-Ray Detectors (GRDs). Each GRD module is comprised of a LaBr3:Ce scintillator, SiPM array and preamplifier. A large dynamic range is achieved by the high gain and low gain channels of the preamplifier. This article discusses the performance of a GRD prototype which includes a set of radioactive sources in the range of 5.9-1332.5 keV. The energy resolution and energy to ADC channel conversion of the GRD module are also discussed. The typical energy resolution is 5.3% at 662 keV (FWHM) which meets the relevant requirements (< 8% at 662 keV). The energy calibration capability is evaluated by the measured intrinsic activity of LaBr3:Ce and Geant4 simulation results. The test results demonstrate the feasibility of the GECAM GRD design.
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 detect
We present ECLAIRs, the Gamma-ray burst (GRB) trigger camera to fly on-board the Chinese-French mission SVOM. ECLAIRs is a wide-field ($sim 2$,sr) coded mask camera with a mask transparency of 40% and a 1024 $mathrm{cm}^2$ detection plane coupled to a data processing unit, so-called UGTS, which is in charge of locating GRBs in near real time thanks to image and rate triggers. We present the instrument science requirements and how the design of ECLAIRs has been optimized to increase its sensitivity to high-redshift GRBs and low-luminosity GRBs in the local Universe, by having a low-energy threshold of 4 keV. The total spectral coverage ranges from 4 to 150 keV. ECLAIRs is expected to detect $sim 200$ GRBs of all types during the nominal 3 year mission lifetime. To reach a 4 keV low-energy threshold, the ECLAIRs detection plane is paved with 6400 $4times 4~mathrm{mm}^2$ and 1 mm-thick Schottky CdTe detectors. The detectors are grouped by 32, in 8x4 matrices read by a low-noise ASIC, forming elementary modules called XRDPIX. In this paper, we also present our current efforts to investigate the performance of these modules with their front-end electronics when illuminated by charged particles and/or photons using radioactive sources. All measurements are made in different instrument configurations in vacuum and with a nominal in-flight detector temperature of $-20^circ$C. This work will enable us to choose the in-flight configuration that will make the best compromise between the science performance and the in-flight operability of ECLAIRs. We will show some highlights of this work.
A beam test of GLAST (Gamma-ray Large Area Space Telescope) components was performed at the Stanford Linear Accelerator Center in October, 1997. These beam test components were simp
Performance demands for high and super-high luminosity at the LHC (up to 10^35 cm^(-2) sec^(-1) after the 2017 shutdown) and at future colliders demand high resolution tracking detectors with very fast time response and excellent temporal and spatial resolution. We are investigating a new radiation detector technology based on Plasma Display Panels (PDP), the underlying engine of panel plasma television displays. The design and production of PDPs is supported by four decades of industrial development. Emerging from this television technology is the Plasma Panel Sensor (PPS), a novel variant of the micropattern radiation detector. The PPS is fundamentally an array of micro-Geiger plasma discharge cells operating in a non-ageing, hermetically sealed gas mixture . We report on the PPS development program, including design of a PPS Test Cell.