The « 3-D donut » electrostatic analyzer for millisecond timescale electron measurements in the solar wind

International audienceUnderstanding electron acceleration mechanisms in planetary magnetospheres or energy dissipation at electron scale in the solar wind requires fast measurement of electron distribution functions on a millisecond time scale. Still, since the beginning of space age, the instantaneous field of view of plasma spectrometers is limited to a few degrees around their viewing plane. In Earth's magnetosphere, the NASA MMS spacecraft use 8 state-of-the-art sensor heads to reach a time resolution of 30 milliseconds. This costly strategy in terms of mass and power consumption can hardly be extended to the next generation of constellation missions that would use a large number of small-satellites. In the solar wind, using the same sensor heads, the ESA THOR mission is expected to reach the 5ms timescale in the thermal energy range, up to 100eV. We present the « 3-D donut » electrostatic analyzer concept that can change the game for future space missions because of its instantaneous hemispheric field of view. A set of 2 sensors is sufficient to cover all directions over a wide range of energy, e.g. up to 1-2keV in the solar wind, which covers both thermal and supra-thermal particles. In addition, its high sensitivity compared to state of the art instruments opens the possibility of millisecond time scale measurements in space plasmas. With CNES support, we developed a high fidelity prototype (a quarter of the full « 3-D donut » analyzer) that includes all electronic sub-systems. The prototype weights less than a kilogram. The key building block of the instrument is an imaging detector that uses EASIC, a low-power front-end electronics that will fly on the ESA Solar Orbiter and on the NASA Parker Solar Probe missions

Conception d'un stimulateur implantable dédié à la stimulation électrique fonctionnelle

MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Low power hard-rad electronics for particle detection in space plasmas

International audienceParticle detection in highly-radiative environment is one of the experimental challenges of planetary exploration. We present the design and performances of a compact electron detector that takes advantage of the development of a hard-rad and ultra low-power front-end electronics. The Applied Specific Integrated Circuit (ASIC) consists of charge sensitive amplifiers and discriminators allowing a 4.5MHz periodic counting rate. The 16-channels ASIC only takes 30mW of power which is the power budget of single channel hybrid components with similar performances. Each channel can be independently configured in order to adjust the detection threshold of the discriminator. An internal test circuitry is used to monitor the behavior of the electronics. This component, that has been tested at high ionizing doses, is immune to Single Event Latchups up to at least 80 MeV.cm²/mg and it will fly on the Solar Orbiter ESA mission

Innovative particle detector for future heliophysics missions

International audienceInnovative particle detectors are needed for future heliophysics missions in order to access to high-time resolution phenomena within limited resources. One of the main challenges is to accurately monitor solar wind plasmas from non-spinning platforms. Such an innovative particle detector which is based on a new optical concept allows the coverage of 4pi str solid angle with only two sensor heads. It fits the need of all-sky thermal plasma measurements on three axis stabilized spacecraft which are the most commonly used platforms for heliophysics missions with imaging capabilities. This 3D field-of-view plasma analyzer also takes advantage of the new possibilities offered by the development of an ultra low-power multichannel charge sensitive amplifier used for the imaging detector of the instrument. We present the design and measured performances of a prototype model that will fly on a test rocket in 2014. One of the possible applications of this innovative particle detector is the investigation of electron time scale phenomena in the turbulent solar wind of the inner heliosphere with unprecedented time resolution below 10 msec

Innovative particle detector for future heliophysics missions

International audienceInnovative particle detectors are needed for future heliophysics missions in order to access to high-time resolution phenomena within limited resources. One of the main challenges is to accurately monitor solar wind plasmas from non-spinning platforms. Such an innovative particle detector which is based on a new optical concept allows the coverage of 4pi str solid angle with only two sensor heads. It fits the need of all-sky thermal plasma measurements on three axis stabilized spacecraft which are the most commonly used platforms for heliophysics missions with imaging capabilities. This 3D field-of-view plasma analyzer also takes advantage of the new possibilities offered by the development of an ultra low-power multichannel charge sensitive amplifier used for the imaging detector of the instrument. We present the design and measured performances of a prototype model that will fly on a test rocket in 2014. One of the possible applications of this innovative particle detector is the investigation of electron time scale phenomena in the turbulent solar wind of the inner heliosphere with unprecedented time resolution below 10 msec

3D plasma camera for planetary missions

International audienceA new 3D field-of-view toroidal space plasma analyzer based on an innovative optical concept allows the coverage of 4pi str solid angle with only two sensor heads. It fits the need of all-sky thermal plasma measurements on three-axis stabilized spacecraft which are the most commonly used platforms for planetary missions. The 3D plasma analyzer also takes advantage of the new possibilities offered by the development of an ultra low-power multi-channel charge sensitive amplifier used for the imaging detector of the instrument. We present the design and measured performances of a prototype model that will fly on a test rocket in 2014

Design and Characterization of a High Dynamic Range and Ultra Low Power 16-Channel ASIC for an Innovative 3D Imaging Space Plasma Analyzer

International audienceA very low power 16-channel ASIC has been designed and fabricated in a standard 0.35 $mu{hbox{m}}$ CMOS technology. It is to be used as the front-end electronics of the micro-channel plates (MCPs) based detector of a 3D space plasma analyzer. Each channel includes a charge sensitive amplifier (CSA) and a discriminator. With a CSA conversion gain of 0.5 mV/fC, the ASIC is able to detect charges emitted by the MCPs over a wide dynamic range of 10 fC to 3.5 pC. The CSA pulse-pair-resolution (PPR) is 170 ns, and the maximum counting rate frequency is 7.5 MHz for input charges limited to 100 fC and 4.6 MHz for full scale inputs. The CSA input devices are optimized for a detector capacitance varying in the range of 2-12 pF. The measured input equivalent noise charge $({hbox{ENC}}_{rm in})$ is 1.3 fC $+$ 0.1 fC/pF rms. These features have been obtained with an unprecedented low power consumption of only 0.64 mW per channel. Experimental tests under the extended temperature range of $-{hbox{40}}~^{circ}{hbox{C}}$ to 85$~^{circ}{hbox{C}}$ have shown no significant performance variations

A high dynamic range and low power 16-channel CMOS circuit for particle detection in space plasmas

International audienceA low power 16-channel ASIC has been designed in the standard 0.35μm CMOS technology. It includes a Charge-Sensitive-Amplifier (CSA) and a discriminator from noise. It is designed using hard-rad layout rules and can be used as the front-end electronics of a 3D imaging space plasma analyser that includes charged particles multipliers (Micro Channel Plates). With a total power consumption limited to 600μW per channel, the detection chain achieves a gain of 1mV/fC over a wide dynamic range of input charges varying from 4fC to 4pC. The CSA Pulse-Pair-Resolution (PPR) is 250ns providing the ability to reach a minimum particle count rate of 4MHz periodic per channel. By adjusting the threshold of discrimination from noise to the limited dynamic range of standard MCP, it is suggested that particle count rates as high as 10MHz periodic can be achieved with this low power ASIC while classical hybrid space qualified components with a similar count rate capability have a power consumption of 25mW per channel

Implantable Autonomous Stimulation Unit for FES

International audienceWe propose an implantable autonomous stimulation unit for Functional Electrical Stimulation (FES) of motor nerves, for spinal cord injured patients. Thus, we mainly focus on the prototype of such implanted device interfaced with neural structures by means of multipolar electrodes

New Implantable Stimulator for the FES of Paralyzed Muscles

International audienceWe propose a new implantable circuit for the internal Functional Electrical Stimulation (FES) of motor nerves for paraplegic people. The circuit is designed to deliver precise calibrated stimulation pulses to specific multipolar electrodes. Several original design features have been developed to respond to the particular specifications imposed by safety constraints. In particular, the DAC has been thought to be fully monotonic and the output stage to ensure a passive and secure discharge of the safety capacitor. Also some tricky features have been added in order to improve the classical charge pump that generates on-chip high voltage