The very last member of the IDeF-X ASIC family is presented: IDeF-X ECLAIRs is a 32-channel front end ASIC designed for the readout of Cadmium Telluride (CdTe) and Cadmium Zinc Telluride (CdZnTe) ...Detectors. Thanks to its noise performance (Equivalent Noise Charge floor of 33 e - rms) and to its radiation hardened design (Single Event Latchup Linear Energy Transfer threshold of 56 MeV.cm 2 .mg -1 ), the chip is well suited for soft X-rays energy discrimination and high energy resolution, ldquospace proof,rdquo hard X-ray spectroscopy. We measured an energy low threshold of less than 4 keV with a 10 pF input capacitor and a minimal reachable sensitivity of the Equivalent Noise Charge (ENC) to input capacitance of less than 7 e - /pF obtained with a 6 mus peak time. IDeF-X ECLAIRs will be used for the readout of 6400 CdTe Schottky monopixel detectors of the 2D coded mask imaging telescope ECLAIRs aboard the SVOM satellite. IDeF-X ECLAIRs (or IDeF-X V2) has also been designed for the readout of a pixelated CdTe detector in the miniature spectro-imager prototype Caliste 256 that is currently foreseen for the high energy detector module of the Simbol-X mission.
Aims.
The Spectrometer Telescope for Imaging X-rays (STIX) on Solar Orbiter is a hard X-ray imaging spectrometer, which covers the energy range from 4 to 150 keV. STIX observes hard X-ray ...bremsstrahlung emissions from solar flares and therefore provides diagnostics of the hottest (⪆10 MK) flare plasma while quantifying the location, spectrum, and energy content of flare-accelerated nonthermal electrons.
Methods.
To accomplish this, STIX applies an indirect bigrid Fourier imaging technique using a set of tungsten grids (at pitches from 0.038 to 1 mm) in front of 32 coarsely pixelated CdTe detectors to provide information on angular scales from 7 to 180 arcsec with 1 keV energy resolution (at 6 keV). The imaging concept of STIX has intrinsically low telemetry and it is therefore well-suited to the limited resources available to the Solar Orbiter payload. To further reduce the downlinked data volume, STIX data are binned on board into 32 selectable energy bins and dynamically-adjusted time bins with a typical duration of 1 s during flares.
Results.
Through hard X-ray diagnostics, STIX provides critical information for understanding the acceleration of electrons at the Sun and their transport into interplanetary space and for determining the magnetic connection of Solar Orbiter back to the Sun. In this way, STIX serves to link Solar Orbiter’s remote and in-situ measurements.
Context.
Solar Orbiter strives to unveil how the Sun controls and shapes the heliosphere and fills it with energetic particle radiation. To this end, its Energetic Particle Detector (EPD) has now ...been in operation, providing excellent data, for just over a year.
Aims.
EPD measures suprathermal and energetic particles in the energy range from a few keV up to (near-) relativistic energies (few MeV for electrons and about 500 MeV nuc
−1
for ions). We present an overview of the initial results from the first year of operations and we provide a first assessment of issues and limitations. In addition, we present areas where EPD excels and provides opportunities for significant scientific progress in understanding how our Sun shapes the heliosphere.
Methods.
We used the solar particle events observed by Solar Orbiter on 21 July and between 10 and 11 December 2020 to discuss the capabilities, along with updates and open issues related to EPD on Solar Orbiter. We also give some words of caution and caveats related to the use of EPD-derived data.
Results.
During this first year of operations of the Solar Orbiter mission, EPD has recorded several particle events at distances between 0.5 and 1 au from the Sun. We present dynamic and time-averaged energy spectra for ions that were measured with a combination of all four EPD sensors, namely: the SupraThermal Electron and Proton sensor (STEP), the Electron Proton Telescope (EPT), the Suprathermal Ion Spectrograph (SIS), and the High-Energy Telescope (HET) as well as the associated energy spectra for electrons measured with STEP and EPT. We illustrate the capabilities of the EPD suite using the 10 and 11 December 2020 solar particle event. This event showed an enrichment of heavy ions as well as
3
He, for which we also present dynamic spectra measured with SIS. The high anisotropy of electrons at the onset of the event and its temporal evolution is also shown using data from these sensors. We discuss the ongoing in-flight calibration and a few open instrumental issues using data from the 21 July and the 10 and 11 December 2020 events and give guidelines and examples for the usage of the EPD data. We explain how spacecraft operations may affect EPD data and we present a list of such time periods in the appendix. A list of the most significant particle enhancements as observed by EPT during this first year is also provided.
We present the IDeF-X HDBD integrated circuit, our latest 32-channel application specified integrated circuit devoted to semiconductor photon counting X-ray detectors, designed to read charges ...ranging from −40 to 40 fC. The chip reaches an equivalent noise charge (ENC) floor of 17 electrons rms and is optimized for low input capacitance (< 10 pF). Each channel is based on an optimized charge sensitive amplifier (CSA) followed by a CR-RC 2 filter and a peak detector with a power consumption of <inline-formula> <tex-math notation="LaTeX">850 ~\mu \text{W} </tex-math></inline-formula>/channel. Gain and shaping times are tunable. This circuit has been designed with radiation mitigation techniques to meet space application requirements. This ASIC can read either cadmium telluride or silicon detectors for imaging-spectroscopy applications. An energy resolution of 230-eV FHWM at 6 keV and a low-level threshold of 1.2 keV were demonstrated with a single pixel silicon drift detector connected to one channel.
Characterization of the magnetic fields at different scales in the Universe is a new frontier for submillimeter astronomy. Polarimetric measurements between 50 and 500 µm are the golden path for this ...research. We develop, in the prospect of space observatories, all-silicon 50 mK bolometer arrays with polarimetric capabilities in the pixel. Here, we present the first results of the new detectors: performances of thermal sensors, optical absorption and polarimetry.
This paper describes a 16x16 pixels CdTe-based X-ray detector named dimension 2 revision 1 (D 2 R 1 ) with a pixel size of 300 μm x 300 μm. An application-specific integrated circuit (ASIC) is ...interconnected to a CdTe detector by means of an indium gold stud bonding process. This ASIC has a mean equivalent noise charge of 29 el.rms (at 0 pF). The combination of a low capacitance interconnection and low-dark-current detector (0.5 pA) with an optimized ASIC results in a spectral resolution of 584-eV full-width at half-maximum at 60 keV, an energy threshold of 2 keV with a dynamic range of 250 keV. A filtering stage made of a multicorrelated double sampling allows the system to measure X-ray photons at a frequency of 10 kcounts/s typically suited for low photon flux less than 3000 <inline-formula> <tex-math notation="LaTeX">\text {photons}\cdot \text {cm}^{-2}\cdot \text{s}^{-1} </tex-math></inline-formula>. The energy range, resolution, and timing capability of D 2 R 1 can suite a variety of different applications such as X-ray astrophysics, nuclear safety, or medical applications.
The Energetic Particle Detector Rodríguez-Pacheco, J; Wimmer-Schweingruber, R F; Mason, G M ...
Astronomy & astrophysics,
10/2020, Letnik:
642
Journal Article
Recenzirano
Odprti dostop
After decades of observations of solar energetic particles from space-based observatories, relevant questions on particle injection, transport, and acceleration remain open. To address these ...scientific topics, accurate measurements of the particle properties in the inner heliosphere are needed. In this paper we describe the Energetic Particle Detector (EPD), an instrument suite that is part of the scientific payload aboard the Solar Orbiter mission. Solar Orbiter will approach the Sun as close as 0.28 au and will provide extra-ecliptic measurements beyond ∼30° heliographic latitude during the later stages of the mission. The EPD will measure electrons, protons, and heavy ions with high temporal resolution over a wide energy range, from suprathermal energies up to several hundreds of megaelectronvolts/nucleons. For this purpose, EPD is composed of four units: the SupraThermal Electrons and Protons (STEP), the Electron Proton Telescope (EPT), the Suprathermal Ion Spectrograph (SIS), and the High-Energy Telescope (HET) plus the Instrument Control Unit that serves as power and data interface with the spacecraft. The low-energy population of electrons and ions will be covered by STEP and EPT, while the high-energy range will be measured by HET. Elemental and isotopic ion composition measurements will be performed by SIS and HET, allowing full particle identification from a few kiloelectronvolts up to several hundreds of megaelectronvolts/nucleons. Angular information will be provided by the separate look directions from different sensor heads, on the ecliptic plane along the Parker spiral magnetic field both forward and backwards, and out of the ecliptic plane observing both northern and southern hemispheres. The unparalleled observations of EPD will provide key insights into long-open and crucial questions about the processes that govern energetic particles in the inner heliosphere.
A high-sensitivity cryogenic sub-millimetre camera is planned for the SPICA space observatory. At the heart of this instrument, new all-silicon bolometer arrays integrate
in pixel
instrumental ...polarimetry capabilities.
From 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.
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