A fast and low-noise front-end electronics for amplifying and filtering the signal generated by a silicon detector has been designed, simulated, developed, and characterized as the main part of the detection chain for an instrument devoted to the measurements of low- and medium-energy charged particles in space plasma environments. The targeted low energy threshold is 10 keV with a 10% resolution. The simulated performances of the developed electronics reach a gain bandwidth of up to 16.1 GHz, a noise level at the input of 0.96 nV/Hz(-1/2), and an equivalent noise charge of 4.62 keV. The experimental measurements with injection testing show resolution below 5 keV and a low threshold of 31.46 keV. Radioactive testing shows a resolution of 30.9 keV because the detector capacitance is larger than expected (21 vs 10 pF). A good agreement between simulation with a 21 pF detector capacitance and experimental measurement is achieved within 18%.

BACK TO THE MOON? P.Y. Meslin, H. He, Z. Kang, R. Wimmer-Schweingruber, J.C. Sabroux, J.-F. Pineau, N. Yamashita, B. Sabot, S. Pierre, M. Blanc, J.-P. Roques, I. Plotnikov, S. Maurice, O. Gasnault, J. Amestoy, P. Pinet, O. Forni, J. Lasue, A. Guertin, V. Métivier, N. Michel, N. Servagent, F. Haddad, F. Poirier, C. Koumeir, J. Flahaut, F. Rocard, A. Debus, K.W. Wong, P. Devoto, L. Lavergne, R. Mathon, D. Rambaud, E. Carrié, B. Dubois, N. Striebig, M. Belot, IRAP, UPS/CNRS/CNES, Toulouse (pmeslin at irap.omp.eu), IGG, CAS, Beijing. CUBG, Beijing. CAU, IEAP, Kiel. IRSN, Saclay. Albedo Technologies, St-Sylvestre. PSI, Tucson. CEA, LNE-LNHB, Saclay. SUBATECH, IMT Atlantique, CNRS/IN2P3, Université de Nantes, Nantes. GIP ARRONAX. CRPG, Nancy. CNES, Paris. CNES, Toulouse. GIS, OMP, Toulouse.

The Solar Orbiter mission seeks to make connections between the physical processes occurring at the Sun or in the solar corona and the nature of the solar wind created by those processes which is subsequently observed at the spacecraft. The mission also targets physical processes occurring in the solar wind itself during its journey from its source to the spacecraft. To meet the specific mission science goals, Solar Orbiter will be equipped with both remote-sensing and in-situ instruments which will make unprecedented measurements of the solar atmosphere and the inner heliosphere. A crucial set of measurements will be provided by the Solar Wind Analyser (SWA) suite of instruments. This suite consists of an Electron Analyser System (SWA-EAS), a Proton and Alpha particle Sensor (SWA-PAS), and a Heavy Ion Sensor (SWA-HIS) which are jointly served by a central control and data processing unit (SWA-DPU). Together these sensors will measure and categorise the vast majority of thermal and suprathermal ions and electrons in the solar wind and determine the abundances and charge states of the heavy ion populations. The three sensors in the SWA suite are each based on the top hat electrostatic analyser concept, which has been deployed on numerous space plasma missions. The SWA-EAS uses two such heads, each of which have 360° azimuth acceptance angles and ±45° aperture deflection plates. Together these two sensors, which are mounted on the end of the boom, will cover a full sky field-of-view (FoV) (except for blockages by the spacecraft and its appendages) and measure the full 3D velocity distribution function (VDF) of solar wind electrons in the energy range of a few eV to ∼5 keV. The SWA-PAS instrument also uses an electrostatic analyser with a more confined FoV (−24° to +42° × ±22.5° around the expected solar wind arrival direction), which nevertheless is capable of measuring the full 3D VDF of the protons and alpha particles arriving at the instrument in the energy range from 200 eV/q to 20 keV/e. Finally, SWA-HIS measures the composition and 3D VDFs of heavy ions in the bulk solar wind as well as those of the major constituents in the suprathermal energy range and those of pick-up ions. The sensor resolves the full 3D VDFs of the prominent heavy ions at a resolution of 5 min in normal mode and 30 s in burst mode. Additionally, SWA-HIS measures 3D VDFs of alpha particles at a 4 s resolution in burst mode. Measurements are over a FoV of −33° to +66° × ±20° around the expected solar wind arrival direction and at energies up to 80 keV/e. The mass resolution (m/Δm) is > 5. This paper describes how the three SWA scientific sensors, as delivered to the spacecraft, meet or exceed the performance requirements originally set out to achieve the mission’s science goals. We describe the motivation and specific requirements for each of the three sensors within the SWA suite, their expected science results, their main characteristics, and their operation through the central SWA-DPU. We describe the combined data products that we expect to return from the suite and provide to the Solar Orbiter Archive for use in scientific analyses by members of the wider solar and heliospheric communities. These unique data products will help reveal the nature of the solar wind as a function of both heliocentric distance and solar latitude. Indeed, SWA-HIS measurements of solar wind composition will be the first such measurements made in the inner heliosphere. The SWA data are crucial to efforts to link the in situ measurements of the solar wind made at the spacecraft with remote observations of candidate source regions. This is a novel aspect of the mission which will lead to significant advances in our understanding of the mechanisms accelerating and heating the solar wind, driving eruptions and other transient phenomena on the Sun, and controlling the injection, acceleration, and transport of the energetic particles in the heliosphere.

The Active Monitor Box of Electrostatic Risks (AMBER) is a double-head thermal electron and ion electrostatic analyzer (energy range 0-30 keV) that was launched onboard the Jason-3 spacecraft in 2016. The next generation AMBER instrument, for which a first prototype was developed and then calibrated at the end of 2017, constitutes a significant evolution that is based on a single head to measure both species alternatively. The instrument developments focused on several new sub-systems (front-end electronics, highvoltage electronics, mechanical design) that permit to reduce instrument resources down to ~ 1 kg and 1.5 W. AMBER is designed as a generic radiation monitor with a twofold purpose: (1) measure magnetospheric thermal ion and electron populations in the range 0-35 keV, with significant scientific potential (e.g., plasmasphere, ring current, plasma sheet), and (2) monitor spacecraft electrostatic charging and the plasma populations responsible for it, for electromagnetic cleanliness and operational purposes.

TARANIS (Tool for the Analysis of RAdiation from lightNIng and Sprites) is a microsatellite aimed to atmospheric storms study. It embarks among other instruments IDEE (Instrument Detecteur d'Electron Energetique) which is dedicated to energetic electron characterization in the range from 70keV to 4Mev. To cover such awide ran ge, two types of detectors are required: Silicon (Si) and Cadmium Telluride (CdTe) based detector for the 70keV to 700keV and for the 300keV to 4MeV respectively. Si detectors are placed in front of CdTe detectors for angle measurement. Although the readout architecture of both detectors are similar, the time constants involved in collection of the charges for Si and CdTe are differents by almost 21 decades (60ns for Si and 3f.1s for CdTe). Two different readout circuits are thus required. CdTe type channels need to make use of Pole Zero Cancellation (PZC) technique in order not to impede the frequency of operation. Performance of the design has been characterized on a test board as well as interfaced with detectors. Finally, results of its characterized Single Event Latchup (SEL) performance is given.

Introduction: Time of flight mass spectrometry is widely used to study space plasmas in planetary and solar missions. It provides information about the plasma physical and chemical properties by individ al analysis of particles and statistical processing. However, scientific needs constantly rise and new performances are necessary to achieve a better unde standing of space plasma mechanisms. A research and development projec t has been formed at IRAP to improve this kind of instrument We use grazing incidence microchannel plates ( to replace usual carbon foil for electron emission designed a complete spectrometer prototype to val date the entire instrument concept. W first results and possibilities of improvements.

We present an alternative method for generating start electrons for time of flight (TOF) space plasma analyzers. The technique presented here takes advantage of the processes occurring during the scattering of the particles off a surface, i.e., kinetic electron emission. The use of a thin microchannel plate as a scattering surface allows us to distribute this surface along a single plane normal to the particle velocity. The uncertainty on the TOF distance is thus minimized, allowing a greater mass resolution. The first tests carried out showed that a mass resolution of 10 for a beam energy of 10keV is easily reachable.

A front-end electronics for three-dimensional time-of-flight space plasma analyzers has been developed. These mass spectrometers, allowing the determination of the distribution functions of the main ion species, are based on the selection of the ion energy per charge and arrival direction using an electrostatic analyzer, and on the determination of their velocity from the time separating a start and a stop pulse. The start pulse is provided by the collection on a microchannel plate (MCP) of secondary electrons emitted when each ion crosses a thin carbon foil. The stop pulse is provided by the ion hitting a second MCP. The aim of the electronics presented in this article is to process the signals provided by MCPs to generate logic pulses, allowing the measurement of precise time differences. The design consists of an amplifier and a timing discriminator which performs a timing compensation to eliminate the time walk. A first version of the circuit has been developed and achieves a time walk of ∼400 ps for an input amplitude dynamic range of 25 dB. The total power dissipation per channel is ∼14 mW at an event rate of 100 KHz and ∼19 mW at a rate of 1 MHz. The influence of the temperature on the circuit behavior has been investigated. The performances of the circuit in a complete detector were also evaluated. This circuit is designed to be used in various designs for future missions.