STROBE-X: A probe-class mission for x-ray spectroscopy and timing on timescales from microseconds to years

We describe the Spectroscopic Time-Resolving Observatory for Broadband Energy X-rays (STROBE-X), a probeclass mission concept that will provide an unprecedented view of the X-ray sky, performing timing and spectroscopy over both a broad energy band (0.2-30 keV) and a wide range of timescales from microseconds to years. STROBE-X comprises two narrow-field instruments and a wide field monitor. The soft or low-energy band (0.2-12 keV) is covered by an array of lightweight optics (3-m focal length) that concentrate incident photons onto small solid-state detectors with CCD-level (85-175 eV) energy resolution, 100 ns time resolution, and low background rates. This technology has been fully developed for NICER and will be scaled up to take advantage of the longer focal length of STROBE-X. The higher-energy band (2-30 keV) is covered by large-area, collimated silicon drift detectors that were developed for the European LOFT mission concept. Each instrument will provide an order of magnitude improvement in effective area over its predecessor (NICER in the soft band and RXTE in the hard band). Finally, STROBE-X offers a sensitive wide-field monitor (WFM), both to act as a trigger for pointed observations of X-ray transients and also to provide high duty-cycle, high time-resolution, and high spectral-resolution monitoring of the variable X-ray sky. The WFM will boast approximately 20 times the sensitivity of the RXTE All-Sky Monitor, enabling multi-wavelength and multi-messenger investigations with a large instantaneous field of view. This mission concept will be presented to the 2020 Decadal Survey for consideration

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

Rétine silicium pour la détection/localisation d'éclats lasers

Dans beaucoup d'applications telles que la détection d'obstacle pour les véhicules intelligents, le guidage, la navigation e. t. c, on utilise des rétines électroniques pour détecter une source laser. L'un des principaux problèmes que l'on rencontre dans ce type d'application est la perturbation de la détection par les variations du fond lumineux ambiant. Ce type de rétine est donc souvent difficilement utilisable en extérieure. Dans cette thèse, nous avons proposé une rétine silicium capable de détecter et de localiser une source laser dans un environnement de type rural. Nous avons choisi un signal d'entrée de type pulse étroit pour pouvoir le détecter par filtrage temporel passe haut. Nous avons ainsi conçu un photodétecteur constitué d'un amplificateur rapide de type source commune cascodé rebouclé par une contre réaction sélective assurée par deux transistors utilisés en régime de faible inversion pour n'amplifier que les signaux haute fréquence. Cette cellule analogique a été optimisée dans le contexte du guidage de missile par laser infrarouge. Le photodétecteur optimisé a été réalisé dans un procédé CMOS 0.8 mM (m - mu(grec), M - m) à caisson N et les résultats de mesure ont montré qu'il était capable de détecter un pulse infrarouge (lamda=1.06 mM) de 0.1 mWx20ns dans un fond ambiant dont la puissance pouvait varier d'un facteur 1 à 10^4. Nous avons ensuite conçu le pixel complet: il est constitué du photodétecteur testé, d'un filtre passe haut faible consommation, d'un comparateur, d'un latch, et d'un circuit de sélection. Nous avons implanté un circuit prototype contenant une petite rétine (2x2). Finalement, chaque pixel est capable de détecter un pulse infrarouge de 1mWx20ns. Chaque cellule du pixel a été testée et les résultats des tests ont été discutés en vue d'améliorer la sensibilité du pixel. La sensibilité de la rétine est dégradée par le bruit spatial fixe, mais nous avons conclu que nous pourrions l'augmenter en affinant le dessin des masques.Laser detection by electronic retina can find wide applications: obstacle detection for intelligent automobile, guidance, navigation, etc. One of the major problems met in applications is that the detection can be perturbed by background illumination variation, which makes it difficult to use this kind of retina in outside environnement. In this thesis, we have proposed a silicon retina which can detect and localize a ponctual pulsed laser source in outside environnement. Input pulse has been chosen to have a wide bandwith so that we can try to detect it by high-pass filtering. We have designed a selective photoreceptor which contains a fast amplifier and a selective feedback to amplifier only high frequency signals. The amplifier is a cascoded common source stage and we use two transistors that operate in week inversion to close the loop. This analog cell has been fully studied and optimised in the context of missile guidance by infrared pulsed laser. The optimized photoreceptor has been designed in a 0.8mM CMOS Nwell process and the measurement results have shown that the photoreceptor is able to detect a 0.1mWx20ns infrared (lamda=1.06mM) laser pulse in a backgroud illumination power which can varie from 1 to more than 10^4. We have then designed the complete pixel: it consists of the selective photoreceptor, a low power high-pass filter, a comparator, a latch and a selection circuit. We have designed a new circuit which contained a little retina (2x2). Finaly each pixel of the retina is able to detect a 1mWx20ns infrared laser pulse. Each cell of the pixel has been tested and the measurement results have been discussed to find how we could improve the sensistivity of the pixel. The sensistivity of the whole retina is reduced by fixed spatial noise but we have conclued that we would be able to increase it with minor modifications of the layout.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Performance of CATIA ASIC, the APD readout chip foreseen for CMS Barrel ECAL electronics upgrade at HL-LHC

International audienceThe CMS ECAL barrel electronics will be upgraded for the HL-LHC to meet the latency and bandwidth requirements of the Phase-II Level-1 trigger system. The new front-end electronics will mitigate the increasing noise from the avalanche photodiodes (APDs), discriminate against anomalous APD signals and provide improved timing information. The foreseen solution is to replace the current Charge-Sensitive-Amplifier with a Trans-Impedance Amplifier, which should provide the extra bandwidth needed to maintain the integrity of the detector signal shape.The first ASIC prototype, called CATIA, has been successfully designed in TSMC 130 nm CMOS technology and its test results will be presented

CATIA: APD readout ASIC for CMS phase 2 ECAL electronics upgrade

International audienceThe incoming LHC upgrade to HL‒LHC calls for a change of the ECAL front-end electronics design in order to maintain the present performance of the detector while facing a higher instantaneous luminosity and to optimize the timing resolution while using the existing crystals and APDs. The design of the new front-end electronics is based on the cascading of two ASIC: a fast, dual gain trans-impedance amplifier designed in a 130 nm CMOS process (named CATIA) and a dual ADC designed in a 65 nm CMOS process. The latest test‒beam and laboratory test results of CATIA coupled with an ADC will be presented

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

First-ever test and characterization of the AMS standard bulk 0.35 μm CMOS technology at sub-kelvin temperatures

International audienceFrom medical imaging to particle physics passing, among others, by space applications, integrated readout electronics (ICs) in CMOS technologies are often adopted. When a high sensitivity and a low noise level are required, cooling of detectors and readout electronics is the recommended solution. To maintain a constant cooling temperature, they very often operate at nitrogen and helium-4 liquids temperatures, respectively 77 K and 4.2 K. At these temperatures, Spice parameters of MOSFET transistors may be found in the literature. However, their performances at sub-kelvin temperatures remain unknown because of a lack in scientific publications thereupon. CEA Astrophysics division's focal plane arrays-based bolometers are cooled at 0.1 K. The front-end electronics also. However, a CMOS technology was characterized for the first time at sub-kelvin temperatures. It is shown by measured n and p channel transistors' I-V that the AMS 0.35 μm standard bulk CMOS technology, is still performing at 0.1 K. Despite some specific effects on silicon behaviour at cryogenic temperatures, performances are very satisfactory

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