The Gamma Cube: a new way to explore the gamma-ray sky

International audienceWe propose a new concept to allow the tracking of electrons in a gamma-ray telescope operating in the 5–100 MeV band. The idea of this experiment is to image the ionizing tracks that charged particles produce in a scintillator. It is a pair creation telescope at high energy and a Compton telescope with electron tracking at low energy. The telescope features a large scintillator transparent to the scintillation light, an ad-hoc optical system and a high resolution and highly sensitive imager. The performance perspectives and the advantages of such a system are outstanding but the technical difficulties are serious. A few years of research and development within the scientific community are required to reach the TRL level appropriate to propose the Gamma Cube in response to a flight opportunity

On-ground calibration of the X-ray, gamma-ray, and relativistic electron detector onboard TARANIS

Wada Yuuki, Laurent Philippe, Pailot Damien, et al. On-ground calibration of the X-ray, gamma-ray, and relativistic electron detector onboard TARANIS. Journal of Astronomical Telescopes, Instruments, and Systems 10(2), 7 May 2024 ; https://doi.org/10.1117/1.JATIS.10.2.026005.We developed the X-ray, gamma-ray, and relativistic electron detector (XGRE) onboard the Tool for the Analysis of RAdiation from lightNIngs and Sprites (TARANIS) satellite, to investigate high-energy phenomena associated with lightning discharges such as terrestrial gamma-ray flashes and terrestrial electron beams. XGRE consisted of three sensors. Each sensor has one layer of LaBr3 crystals for X-ray/gamma-ray detections and two layers of plastic scintillators for electron and charged-particle discrimination. Since 2018, the flight model of XGRE was developed, and validation and calibration tests, such as a thermal cycle test and a calibration test with the sensors onboard the satellite, were performed before the launch of TARANIS on 17 November 2020. The energy range of the LaBr3 crystals sensitive to X-rays and gamma rays was determined to be 0.04 to 11.6 MeV, 0.08 to 11.0 MeV, and 0.08 to 11.3 MeV for XGRE1, 2, and 3, respectively. The energy resolution at 0.662 MeV (full width at half maximum) was 20.5%, 25.9%, and 28.6%, respectively. The results from the calibration test were then used to validate a simulation model of XGRE and TARANIS. By performing Monte Carlo simulations with the verified model, we calculated effective areas of XGRE to X-rays, gamma rays, electrons, and detector responses to incident photons and electrons coming from various elevation and azimuth angles

The Large Imaging Spectrometer for Solar Accelerated Nuclei (LISSAN): A next-generation solar γ-ray spectroscopic imaging instrument concept

Models of particle acceleration in solar eruptive events suggest that roughly equal energy may go into accelerating electrons and ions. However, while previous solar X-ray spectroscopic imagers have transformed our understanding of electron acceleration, only one resolved image of γ-ray emission from solar accelerated ions has ever been produced. This paper outlines a new satellite instrument concept—the large imaging spectrometer for solar accelerated nuclei (LISSAN)—with the capability not only to observe hundreds of events over its lifetime, but also to capture multiple images per event, thereby imaging the dynamics of solar accelerated ions for the first time. LISSAN provides spectroscopic imaging at photon energies of 40 keV–100 MeV on timescales of ≲10 s with greater sensitivity and imaging capability than its predecessors. This is achieved by deploying high-resolution scintillator detectors and indirect Fourier imaging techniques. LISSAN is suitable for inclusion in a multi-instrument platform such as an ESA M-class mission or as a smaller standalone mission. Without the observations that LISSAN can provide, our understanding of solar particle acceleration, and hence the space weather events with which it is often associated, cannot be complete

Modeling of Planck-high frequency instrument bolometers using non-linear effects in the thermometers

The Planck satellite, which is planned to be launched in 2007, is dedicated to surveying the Cosmic Microwave Background (CMB) to a high precision. Aboard this mission, the High-Frequency Instrument (HFI) will use 52 NTD Ge spiderweb bolometers made by Caltech-JPL and cooled to 100 mK by a dilution cooler. In this paper, we present a model of these detectors that includes non-linear effects seen in NTD Ge thermometers: electron–phonon decoupling and electrical field effect. We show that this model leads to consider only electrical field effect. Furthermore, the optical characterization of the HFI bolometers clearly shows a non-ideal behavior that is explained by non-linear effects in the thermometer. We finally show that these effects have to be taken into account for optimized CMB observations and to fully understand the physics of semi-conducting bolometers

On-ground calibrations of XGRE: An ultrafast gamma-ray spectrometer onboard the TARANIS mission for TGF studies

International audienceXGRE (X-ray, Gamma-ray and Relativistic Electrons detector) was one of the main instruments onboard the TARANIS satellite. It is an ultra-fast gamma-ray and electron detector, with a 350 ns dead time, built for measuring Terrestrial Gamma-ray Flashes (TGF). In this paper, we will shortly present the TARANIS mission, the design of the XGRE instrument and the measured performances during the instrument calibration at APC, LESIA and payload calibrations done onboard the satellite at CNES

FGS, a multi-mission space gamma-ray spectrometer: Design optimization and first results

International audienceFollowing the failure of the TARANIS (Tool for the Analysis of RAdiation from lightNIng and Sprites) mission launch[1], the French space agency (CNES) funded a R&D program with APC and LESIA laboratories to develop a new gamma-ray spectrometer. The first studies started in 2021 and lead to a new design called FGS (Fast Gamma-ray Spectrometer) based on new GAGG scintillators readout by SiPM and analysed by the IDEAS/APOCAT fast ASIC. This program’s main objective is to build a space qualified FGS prototype before 2024. FGS scientific specifications are based on Terrestrial Gamma-ray Flashes (TGF) science studies but this spectrometer could also be used or optimized for other missions: solar science, astrophysical observations (Gamma-Ray Bursts) or planetology studies. The main instrumental objectives are to detect gamma rays in the [20keV–20MeV] energy range with high count rate abilities and a large detection surface. In this paper, we will present our FGS concept and the first spectroscopic results we obtained, consistent on ground with our scientific requirements

FGS, a multi-mission space gamma-ray spectrometer: Design optimization and first results

International audienceFollowing the failure of the TARANIS (Tool for the Analysis of RAdiation from lightNIng and Sprites) mission launch[1], the French space agency (CNES) funded a R&D program with APC and LESIA laboratories to develop a new gamma-ray spectrometer. The first studies started in 2021 and lead to a new design called FGS (Fast Gamma-ray Spectrometer) based on new GAGG scintillators readout by SiPM and analysed by the IDEAS/APOCAT fast ASIC. This program’s main objective is to build a space qualified FGS prototype before 2024. FGS scientific specifications are based on Terrestrial Gamma-ray Flashes (TGF) science studies but this spectrometer could also be used or optimized for other missions: solar science, astrophysical observations (Gamma-Ray Bursts) or planetology studies. The main instrumental objectives are to detect gamma rays in the [20keV–20MeV] energy range with high count rate abilities and a large detection surface. In this paper, we will present our FGS concept and the first spectroscopic results we obtained, consistent on ground with our scientific requirements

FGS, a multi-mission space gamma-ray spectrometer: Design optimization and first results

International audienceFollowing the failure of the TARANIS (Tool for the Analysis of RAdiation from lightNIng and Sprites) mission launch[1], the French space agency (CNES) funded a R&D program with APC and LESIA laboratories to develop a new gamma-ray spectrometer. The first studies started in 2021 and lead to a new design called FGS (Fast Gamma-ray Spectrometer) based on new GAGG scintillators readout by SiPM and analysed by the IDEAS/APOCAT fast ASIC. This program’s main objective is to build a space qualified FGS prototype before 2024. FGS scientific specifications are based on Terrestrial Gamma-ray Flashes (TGF) science studies but this spectrometer could also be used or optimized for other missions: solar science, astrophysical observations (Gamma-Ray Bursts) or planetology studies. The main instrumental objectives are to detect gamma rays in the [20keV–20MeV] energy range with high count rate abilities and a large detection surface. In this paper, we will present our FGS concept and the first spectroscopic results we obtained, consistent on ground with our scientific requirements

On-ground calibration of the X-ray, gamma-ray, and relativistic electron detector onboard TARANIS

International audienceWe developed the X-ray, Gamma-ray and Relativistic Electron detector (XGRE) onboard the TARANIS satellite, to investigate high-energy phenomena associated with lightning discharges such as terrestrial gamma-ray flashes and terrestrial electron beams. XGRE consisted of three sensors. Each sensor has one layer of LaBr$_{3}$ crystals for X-ray/gamma-ray detections, and two layers of plastic scintillators for electron and charged-particle discrimination. Since 2018, the flight model of XGRE was developed, and validation and calibration tests, such as a thermal cycle test and a calibration test with the sensors onboard the satellite were performed before the launch of TARANIS on 17 November 2020. The energy range of the LaBr$_{3}$ crystals sensitive to X-rays and gamma rays was determined to be 0.04-11.6 MeV, 0.08-11.0 MeV, and 0.08-11.3 MeV for XGRE1, 2, and 3, respectively. The energy resolution at 0.662 MeV (full width at half maximum) was to be 20.5%, 25.9%, and 28.6%, respectively. Results from the calibration test were then used to validate a simulation model of XGRE and TARANIS. By performing Monte Carlo simulations with the verified model, we calculated effective areas of XGRE to X-rays, gamma rays, electrons, and detector responses to incident photons and electrons coming from various elevation and azimuth angles

The Large Imaging Spectrometer for Solar Accelerated Nuclei (LISSAN): A Next-Generation Solar γ-ray Spectroscopic Imaging Instrument Concept

Models of particle acceleration in solar eruptive events suggest that roughly equal energy may go into accelerating electrons and ions. However, while previous solar X-ray spectroscopic imagers have transformed our understanding of electron acceleration, only one resolved image of γ-ray emission from solar accelerated ions has ever been produced. This paper outlines a new satellite instrument concept—the large imaging spectrometer for solar accelerated nuclei (LISSAN)—with the capability not only to observe hundreds of events over its lifetime, but also to capture multiple images per event, thereby imaging the dynamics of solar accelerated ions for the first time. LISSAN provides spectroscopic imaging at photon energies of 40 keV–100 MeV on timescales of ≲10 s with greater sensitivity and imaging capability than its predecessors. This is achieved by deploying high-resolution scintillator detectors and indirect Fourier imaging techniques. LISSAN is suitable for inclusion in a multi-instrument platform such as an ESA M-class mission or as a smaller standalone mission. Without the observations that LISSAN can provide, our understanding of solar particle acceleration, and hence the space weather events with which it is often associated, cannot be complete