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

The large area detector onboard the eXTP mission

The Large Area Detector (LAD) is the high-throughput, spectral-timing instrument onboard the eXTP mission, a flagship mission of the Chinese Academy of Sciences and the China National Space Administration, with a large European participation coordinated by Italy and Spain. The eXTP mission is currently performing its phase B study, with a target launch at the end-2027. The eXTP scientific payload includes four instruments (SFA, PFA, LAD and WFM) offering unprecedented simultaneous wide-band X-ray timing and polarimetry sensitivity. The LAD instrument is based on the design originally proposed for the LOFT mission. It envisages a deployed 3.2 m2 effective area in the 2-30 keV energy range, achieved through the technology of the large-area Silicon Drift Detectors - offering a spectral resolution of up to 200 eV FWHM at 6 keV - and of capillary plate collimators - limiting the field of view to about 1 degree. In this paper we will provide an overview of the LAD instrument design, its current status of development and anticipated performance

Etude et optimisation du plan de détection de haute énergie en Cd(Zn)Te pour la mission spatiale d'observation astronomie X et gamma SIMBOL-X

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Cd(Zn)Te Detectors for Hard X-Ray and Gamma-Ray Astronomy

The energy range of hard X-rays and gamma-rays is dominated by non-thermal emissions. Physical processes such as particle acceleration, accretion, and nucleosynthesis are observable and are at play in the most violent phenomena of the Universe (e.g., supernovae, relativistic jets, gamma ray bursts). Despite the importance of information from hard X-rays and gamma-rays for the understanding of the enigmatic compact objects, this science suffers from instrumental limitations in the development of space systems with good detection efficiency. Complementing the success of high resistivity silicon and high purity germanium, the need for new high density and high atomic number (Z) materials has quickly become crucial. While CdTe-based material has been identified as a good candidate since the 1970s, producing good detectors from the crystal growth to the implementation in a detection system is complex. High-energy astrophysics in space instruments is very demanding in terms of crystal quality and uniformity compared to other industrial applications (medical imaging, homeland security, nuclear safety). Charge carrier mobility and lifetime must be maximized to allow full charge collection; high resistivity allows low leakage current at room temperature or with moderate cooling. Both parameters are key factors for the spectral performance of detectors. Advances in device imaging capabilities are also crucial to this domain of astrophysics even though most sources are point sources; this allows the use of hard X-ray focusing optics to improve telescope sensitivity by several orders of magnitude and this additionally provides polarimetric capability. The imaging capability obviously benefits the observation of extended sources, such as supernova remnants and closer to us, solar flares. We review here the key parameters to produce, design, and implement a detection system based on Cd(Zn)Te detectors, in the prospect of exploiting the light information from the astrophysics sources in the best possible way by providing optimal detection efficiency, spectral, imaging, or polarimetric performances. Combining these capabilities in a single system is possible, which is a great advantage of such material, given some design trade-offs. The illustrations with realized space instruments are the best examples of possible implementations

IDeF-X HD: A CMOS ASIC for the Readout of Cd(Zn)Te Detectors for Space-Borne Applications

International audienceIDeF-X HD is a 32-channel analog front-end with self-triggering capability optimized for the readout of 16×16 pixels CdTe or CdZnTe pixelated detectors to build a low power micro-gamma camera. IDeF-X HD has been designed in the standard AMS CMOS 0.35μm process technology. Its power consumption is 800μW per channel. The energy range of the ASIC can be extended to 1.1MeV thanks to the in-channel adjustable gain stage. When no detector is connected to the chip and without input current, a 33 electrons rms ENC level is achieved after shaping with 10.7μs peaking time. Spectroscopy measurements have been performed with CdTe Schottky detectors. We measured an energy resolution of 4.2keV FWHM at 667keV (137Cs) on a single-pixel configuration. Meanwhile, we also measured 562eV and 666eV FWHM at 14keV and 60keV, respectively (241Am) with a 256 small pixel array and a low detection threshold of 1.2keV. Since IDeF-X HD is intended for space-borne applications in astrophysics, we evaluated its radiation tolerance and its sensitivity to single event effects. We demonstrated that the ASIC remained fully functional without significant degradation of its performances after 200 krad and that no single event latch-up was detected putting the linear energy transfer threshold above 110MeV/(mg/cm2). Good noise performance and radiation tolerance make the chip well suited for X-rays energy discrimination and high energy resolution. The chip is space qualified and flies on board of the solar orbiter ESA mission launched in 2020

The spectrometer telescope for imaging X-rays (STIX) on board Solar Orbiter

International audienc

Low Energy Characterization of Caliste HD, a Fine Pitch CdTe-Based Imaging Spectrometer

International audienceCaliste HD is a recently developed micro-camera designed for X and gamma-ray astronomy, based on a 1×1 cm$^2$ CdTe Schottky pixelated detector. Its entire surface is composed of 256 pixels, disposed on a 16 × 16 pixel array. This spectrometer is buttable on its 4 sides and can be used to create a large focal plane. It is also designed for space environment. Its IDeF-X front-end electronics has low power consumption, excellent noise performance and a wide dynamic range, from 2 keV to 1 MeV. Moreover, electronic noise performances of this device were optimized to set the low level energy threshold lower than 2 keV.This paper focuses on the Caliste HD performance near the low energy limit. For this purpose, we have exposed the CalisteHD module to a mono-energetic X-ray beam, and set energies between 2 and 12 keV. We measured accurately the detectionefficiency in this energy range and found it to be ranging from 39% to 75% for energies from 2.2 keV to 11.6 keV, consideringonly particles detected in the single-event photopeak and ignoring events impinging between two adjacent pixels. Thisefficiency detection profile thereby highlights crucial effects of the Pt electrode opacity on Caliste HD low energy response, andsuggests the presence of absorption zones at the interface between CdTe crystal and platinum. Respective thickness of eachlayer were estimated by simulation and confirmed by RBS ($Rutherford\ Backscattering\ Spectroscopy$).Besides, using a mono-energetic beam allows fine energy resolution measurement, which was found to be ranging from560 to 760 eV FWHM between 2 and 12 keV. In addition, the linearity of this spectrometer and the issue of charge sharingbetween adjacent pixels were studied. This study revealed that spectroscopic performances remain excellent for such boundaryoperating conditions

The spectrometer telescope for imaging X-rays (STIX) on board Solar Orbiter

International audienc