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Papers by Gérard Chanteur

Due to their complementary performances search-coil and flux-gate magnetometers are commonly used... more Due to their complementary performances search-coil and flux-gate magnetometers are commonly used in association onboard scientific spacecraft to measure magnetic field fluctuations. Flux-gates have an almost constant sensitivity from DC up to a few tens of Hz, meanwhile search-coils have a frequency dependent sensitivity, usually having a very flat minimum around a resonance frequency fixed by design. The sensitivities of these instruments cross over around 1Hz: search-coils have a much better sensitivity than flux-gates above this frequency, as low as a few fT/sqrt(Hz), and are usually designed to cover frequency bands extending over four to five decades. Frequency bands of ordinary search-coils can be chosen by design from typically [0.1Hz, 10kHz] to [10Hz, 100kHz]. We present the principle of a new instrument, the dual-band search-coil which has an effective frequency band from 0.1Hz to 1MHz. Two coils, one BF and one HF, share the same magnetic core owing to a mutual reducer wh...

Planetary and Space Science, 2010

The BepiColombo Mercury Magnetospheric Orbiter (MMO) spacecraft includes the plasma and radio wav... more The BepiColombo Mercury Magnetospheric Orbiter (MMO) spacecraft includes the plasma and radio wave observation system called Plasma Wave Investigation (PWI). Since the receivers for electric field, plasma waves, and radio waves are not installed in any of the preceding spacecraft to Mercury, the PWI will provide the first opportunity for conducting in-situ and remote-sensing observations of electric fields, plasma waves, and radio waves in the Hermean magnetosphere and exosphere. These observations are valuable in studying structure, dynamics, and energy exchange processes in the unique magnetosphere of Mercury. They are characterized by the key words of the non-MHD environment and the peculiar interaction between the relatively large planet without ionosphere and the solar wind with high dynamic pressure. The PWI consists of three sets of receivers (EWO, SORBET, and AM 2 P), connected to two sets of electric field sensors (MEFISTO and WPT) and two kinds of magnetic field sensors (LF-SC and DB-SC). The PWI will observe both waveforms and frequency spectra in the frequency range from DC to 10 MHz for the electric field and from 0.3 Hz to 640 kHz for the magnetic field. From 2008, we will start the development of the engineering model, which is conceptually consistent with the flight model design. The present paper discusses the significance and objectives of plasma/radio wave observations in the Hermean magnetosphere, and describes the PWI sensors, receivers and their performance as well as the onboard data processing.

Annales Geophysicae, Dec 21, 2006

HAL (Le Centre pour la Communication Scientifique Directe), Mar 1, 2012

Le vent solaire interagit fortement avec Mars et contribue a l'erosion de son enveloppe gazeu... more Le vent solaire interagit fortement avec Mars et contribue a l'erosion de son enveloppe gazeuse et participe a la dynamique atmospherique. Le couplage electromagnetique avec ces environnements neutres a lieu au travers des processus d'ionisation qui agissent comme catalyseur : l'ionisation par les photons solaires, les echanges de charges, et l'ionisation par impact electronique de leurs hautes atmospheres et leurs exospheres. Un modele 3D decrivant la dynamique des plasmas vent solaire et planetaire au voisinage de la planete a ete developpe (Modolo et al, 2005, 2006, 2012) puis parallelise dans le cadre du projet HELIOSARES (PI : F. Leblanc). Cette parallelisation permet de decrire l'environnement ionise de Mars, de 150 km d'altitude a une dizaine de rayons martiens avec une resolution spatiale de 80 km. Ce modele est complete par une description ionospherique simplifiee, qui par la suite pourra etre remplacee par les resultats du modele ionospherique GCM-LMD (Chaufray, Gonzalez-Galindo, Forget et al). Les resultats du modele magnetospherique (hybride) et l'echappement sont discutes. Les premiers essais d'un couplage entre un modele exospherique thermiques 3D (Yagi, Leblanc et al) et le modele magnetospherique sont egalement abordes.

Cluster Ii Workshop Multiscale Multipoint Plasma Measurements, Feb 1, 2000

Comparative Study of Magnetospheric Systems, 1986

We study the EUV/soft X-ray emission induced by charge transfer between solar wind highly charged... more We study the EUV/soft X-ray emission induced by charge transfer between solar wind highly charged ions and neutral H and O of the Martian exosphere. Results are obtained using three-dimensional hybrid simulations of the global plasma environment of Mars, including photoionization and electron impact ionization of neutral H and O coronae. We calculate projected emission maps from different vantage points

The Physics of Fluids, 1987

In some commonly occurring situations, such as a stratified fluid with two layers or a plasma wit... more In some commonly occurring situations, such as a stratified fluid with two layers or a plasma with a two-temperature electron component, the long waves are adequately described by a Korteweg–de Vries (KdV) equation having positive or negative solitary wave solutions, depending upon the sign of the quadratic term. For critical values of the physical parameters, the quadratic nonlinearity vanishes and the KdV equation is replaced by a modified KdV (or mKdV) equation. This paper concerns the mKdV equation having a cubic nonlinearity with a negative coefficient. The initial value problem with different asymptotic levels, u1 far to the left and u2 far to the right, is investigated both analytically and numerically, for this mKdV− equation. The necessary and sufficient condition u1u2<0 is demonstrated for a shocklike solution to form, also named double layer (dl) in plasma physics.

The Cluster and Phoenix Missions, 1997

Computer Simulation of Space Plasmas, 1985