Expected performance of a Laue lens based on bent crystals

In the context of the LAUE project devoted to build a long focal length focusing optics for soft gamma-ray astronomy (70/100 keV to $>$600 keV), we present results of simulation of a Laue lens, based on bent crystals in different assembling configurations (quasi-mosaic and reflection-like geometries). The main aim is to significantly overcome the sensitivity limits of the current generation of gamma-ray telescopes and improve the imaging capability.Comment: 7 pages, 7 figures, presented at the Space Telescopes and Instrumentation Symposium 2012: Ultraviolet to Gamma Ray Conference. Published in Proceedings of the SPIE, Volume 8443, id. 844331-844331-7 (2012

Bent crystal selection and assembling for the LAUE project

For the first time, with the Laue project, bent crystals are being used for focusing photons in the 80-300 keV energy range. The advantage is their high reflectivity and better Point Spread Function with respect to the mosaic flat crystals. Simulations have already shown their excellent focusing capability which makes them the best candidates for a Laue lens whose sensitivity is also driven by the size of the focused spot. Selected crystals are Germanium (perfect, (111)) and Gallium Arsenide (mosaic, (220)) with 40 m curvature radius to get a spherical lens with 20 m long focal length. A lens petal is being built. We report the measurement technique by which we are able to estimate the exact curvature of each tile within a few percent of uncertainty and their diffraction efficiency. We also discuss some results.Comment: 9 pages, 15 figures, SPIE conference vol. 8861 (2013

Results of the simulations of the petal/lens as part of the LAUE project

In the context of the LAUE project for focusing hard X-/gamma rays, a petal of the complete lens is being assembled at the LARIX facility in the Department of Physics and Earth Science of the University of Ferrara. The lens petal structure is composed of bent Germanium and Gallium Arsenide crystals in transmission geometry. We present the expectations derived from a mathematical model of the lens petal. The extension of the model for the complete LAUE project in the 90 -- 600 keV energy range will be discussed as well. A quantitative analysis of the results of these simulations is also presented.Comment: 12 pages, 26 figures, SPIE optics + Photonics conference 2013, Vol: 886

GAMMA-FLASH Software Design Document of the Data Acquisition System

The present document defines and describes the software architecture of the Data Acquisition and Control System (DACS) of the GAMMA-FLASH project. The intended audience of this document are the potential users of the GAMMA-FLASH project, systems engineers, instrument scientists, designers, developers, testers (either unit or integration), and any contractor involved in the GAMMA-FLASH project who has in charge of the production of any sub-system which interfaces the DACS

Imaging performance above 150 keV of the wide field monitor on board the ASTENA concept mission

A new detection system for X-/Gamma-ray broad energy passband detectors for astronomy has been developed. This system is based on Silicon Drift Detectors (SDDs) coupled with scintillator bars; the SDDs act as a direct detector of soft (<30 keV) X-ray photons, while hard X-/Gamma-rays are stopped by the scintillator bars and the scintillation light is collected by the SDDs. With this configuration, it is possible to build compact, position sensitive detectors with unprecedented energy passband (2 keV - 10/20 MeV). The X and Gamma-ray Imaging Spectrometer (XGIS) on board the THESEUS mission, selected for Phase 0 study for M7, exploits this innovative detection system. The Wide Field Monitor - Imager and Spectrometer (WFM-IS) of the ASTENA (Advanced Surveyor of Transient Events and Nuclear Astrophysics) mission concept consists of 12 independent detection units, also based on this new technology. For the WFM-IS, a coded mask provides imaging capabilities up to 150 keV, while above this limit the instrument will act as a full sky spectrometer. However, it is possible to extend imaging capabilities above this limit by alternatively exploiting the Compton kinematics reconstruction or by using the information from the relative fluxes measured by the different cameras. In this work, we present the instrument design and results from MEGAlib simulations aimed at evaluating the effective area and the imaging performances of the WFM-IS above 150 keV

The Gamma-Flash data acquisition system for observation of terrestrial gamma-ray flashes

Gamma-Flash is an Italian project funded by the Italian Space Agency (ASI) and led by the National Institute for Astrophysics (INAF), devoted to the observation and study of high-energy phenomena, such as terrestrial gamma-ray flashes and gamma-ray glows produced in the Earth's atmosphere during thunderstorms. The project's detectors and the data acquisition and control system (DACS) are placed at the "O. Vittori" observatory on the top of Mt. Cimone (Italy). Another payload will be placed on an aircraft for observations of thunderstorms in the air. This work presents the architecture of the data acquisition and control system and the data flow.Comment: 4 pages, 1 figure, Astronomical Data Analysis Software and System XXXII (2022

The TRILL project: increasing the technological readiness of Laue lenses

Hard X-/soft Gamma-ray astronomy (> 100 keV) is a crucial field for the study of important astrophysical phenomena such as the 511 keV positron annihilation line in the Galactic center region and its origin, gamma-ray bursts, soft gamma-ray repeaters, nuclear lines from SN explosions and more. However, several key questions in this field require sensitivity and angular resolution that are hardly achievable with present technology. A new generation of instruments suitable to focus hard X-/soft Gamma-rays is necessary to overcome the technological limitations of current direct-viewing telescopes. One solution is using Laue lenses based on Bragg's diffraction in a transmission configuration. To date, this technology is in an advanced stage of development and further efforts are being made in order to significantly increase its technology readiness level (TRL). To this end, massive production of suitable crystals is required, as well as an improvement of the capability of their alignment. Such a technological improvement could be exploited in stratospheric balloon experiments and, ultimately, in space missions with a telescope of about 20 m focal length, capable of focusing over a broad energy pass-band. We present the latest technological developments of the TRILL (Technological Readiness Increase for Laue Lenses) project, supported by ASI, devoted to the advancement of the technological readiness of Laue lenses. We show the method we developed for preparing suitable bent Germanium and Silicon crystals and the latest advancements in crystals alignment technology.Comment: arXiv admin note: text overlap with arXiv:2211.1688

Focussing crystals for use in broad band hard X/soft gamma-ray Laue lenses

Hard X-/soft gamma-ray astronomy is a crucial window for the study of the most energetic and violent events in the Universe. To fulfil the scientific requirements in this regime, a new generation of telescopes with a broad operational band extending from tens up to several hundreds of keV and exploiting unprecedented sensitivity (50-100 times better that current instruments) is required. We report on diffractive bent crystals made of Gallium Arsenide (GaAs) that are suitable for the construction of high sensitivity X-/gamma-ray Laue lens space telescopes. Laue lenses, made of sets of diffractive crystals working in transmission, offer one possibility, albeit technically challenging, to build a new generation of focusing telescopes that can extend the energy band far beyond the 80 keV limit for current multilayer concentrators. In particular, we present the results obtained from the characterization of crystals that will be used to realise a broad band Laue demonstrator. They have been studied in terms of focusing capability and diffraction efficiency by using a flat X-ray panel imager and an HPGe spectrometer as focal plane detectors. The GaAs tiles, bent via a surface lapping procedure, have been developed at the IMEM/CNR in Parma (Italy) in the framework of the LAUE project funded by the Italian Space Agency. The main goal of the project was to build a broad band Laue lens demonstrator for hard X-/soft gamma-rays (80-300 keV