G. Matthieussent - Academia.edu (original) (raw)
Uploads
Papers by G. Matthieussent
Physica Scripta, 1994
The generation of high phase-velocity, large-amplitude plasma-wave using plasmas and either elect... more The generation of high phase-velocity, large-amplitude plasma-wave using plasmas and either electron beams or lasers is of fundamental interest for the field of particle accelerator physics. A review is made over the recently performed experiments: electron wake-field at Argone National Laboratory, laser beat-wave with CO2 lasers at I.N.R.S. and U.C.L.A., and with Nd-glass laser at Ecole Polytechnique. With both lasers, electric fields of the order of 1 GV/m have been detected. At U.C.L.A., injected electrons have been accelerated from 1.5 MeV to 10 MeV by the CO2 excited beat wave showing therefore the efficiency of the physical process. Promising photon wake-field experiments are also in preparation.
Journal de Physique III, 1991
The main features of a laboratory experiment devoted to the study of beam-plasma interactions are... more The main features of a laboratory experiment devoted to the study of beam-plasma interactions are described; the production and the principal characteristics of a magnetized plasma created by a steady state or pulsed discharge are presented; a description of the electron gun is given so as the first results concerning the injection of the monokinetic electron beam in the neutral Argon gas. Une expérience d'interaction d'un plasma magnétisé avec un faisceau d'électrons a été réalisée en vue d'applications en géophysique et en physique spatiale. Les caractéristiques du plasma et du faisceau sont présentées. Le plasma est produit en régime continu ou pulsé (densité n \cong 10^{12} e/cm^3, température T \cong 3 eV, champ magnétique B \cong 100 G). Le faisceau d'électrons (énergie E_b \cong 300 eV, intensité I_b \cong 10 mA) se propage à basse pression (P < 5 10^{-4} Torr) et interagit avec le plasma qu'il crée à pression plus élevée.
Journal de Physique, 1982
2014 Une théorie de diffusion ambipolaire permet d'établir l'équation différentielle à laquelle o... more 2014 Une théorie de diffusion ambipolaire permet d'établir l'équation différentielle à laquelle obéit la densité électronique d'un plasma collisionnel diffusant à travers un champ magnétique inhomogène. L'équation de diffusion est résolue numériquement dans une configuration de champ multipolaire, et le profil de potentiel est calculé. Nos résultats permettent d'interpréter le fait que les variations de la densité sont concentrées au voisinage de la paroi, ainsi que l'apparition de régions de potentiel élevé dans une décharge multipolaire. Abstract. 2014 Making use of an ambipolar diffusion theory, the differential equation governing the electronic density of a collisional plasma diffusing through an inhomogeneous magnetic field is established The diffusion equation is solved numerically in the case of a multipolar field and the profile of the potential is calculated. Our results enable us to interpret the fact that the density variations are located in the vicinity of the wall as well as the occurrence of high potential regions in a multipolar discharge. J. Physique 43 (1982) 67-75 JANVIER 1982, Classification Physics Abstracts 52.55K -52.50D
Physics of Fluids, 1976
The nonlinear growth and saturation of the nonresonant beat oscillation driven by two ion-acousti... more The nonlinear growth and saturation of the nonresonant beat oscillation driven by two ion-acoustic waves have been observed. After saturation, the beat signal relaxes into a resonant ion-acoustic wave.
Le Journal de Physique Colloques, 1971
Laser plasma interaction over many Rayleigh lengths is desirable for applications such as plasma ... more Laser plasma interaction over many Rayleigh lengths is desirable for applications such as plasma based accelerators, X ray lasers or fast ignitor concepts. A microcapillary tube can be used as a wave guide to propagate high laser intensities over lengths in the range of 10 th of cm. The conditions for monomode guiding of the laser, the damping length have been obtained analytically and verified i n experiments using one of the laser beam (30mJ, 120fs) of the Laboratoire d'Optique Appliquée facility.
Review of Scientific Instruments, 1990
This paper describes the techniques used to create a fully ionized plasma by the multiphoton ioni... more This paper describes the techniques used to create a fully ionized plasma by the multiphoton ionization of gases at pressures of a few Torr to give an initial electron density precision of better than a few percent, necessary for beat-wave experiments. A gas containment vessel has been constructed using high vacuum techniques with a temperature control system to maintain the
Physical Review Letters, 1975
Nonlinear damping of a broad-band spectrum of plasma waves has been observed. Frequencies lower t... more Nonlinear damping of a broad-band spectrum of plasma waves has been observed. Frequencies lower than the spectrum are growing from background noise. A shift of the entire spectrum towards lower frequencies results. The evolution of the spectrum is in good agreement with the predictions of weak-turbulence theory. Measurements of the electron velocity distribution are presented.
Laser and Particle Beams, 1991
AIP Conference Proceedings, 1999
The acceleration of electrons injected in a plasma wave generated by the laser wakeeld mechanism ... more The acceleration of electrons injected in a plasma wave generated by the laser wakeeld mechanism has been observed. A maximum energy gain of 1.6 MeV has been measured and the maximum longitudinal electric eld is estimated to 1.5 GV/m. The experimental data agree with theoretical predictions when 3D eects are taken into account. The duration of the plasma wave inferred from the number of accelerated electrons is of the order of 1 ps.
Physical Review E, 1998
This Rapid Communication deals with the electron-density measurements using the resonance cone ph... more This Rapid Communication deals with the electron-density measurements using the resonance cone phenomenon in a cold magnetized plasma. The collision frequency limits the modulus of the upper hybrid resonance cone peak and shifts it. Theoretically, this effect is slight and should not affect the electron-density measurements done with this method in magnetized plasmas. The experiment reported in this paper shows that the phenomenological collision frequency introduced in the theoretical potential is much higher than expected on the basis of electron-ion and electron-neutral collisions, so that it is necessary to examine not only the amplitude of the signal but also its phase, in order to estimate this phenomenological frequency and thus the correction to bring about the electron density.
Physics of Fluids B: Plasma Physics, 1993
Physics of Fluids B: Plasma Physics, 1992
ABSTRACT
Revue de Physique Appliquée, 1988
Nous présentons ici des spectres énergétiques des électrons créés au cours de l'explosion de feui... more Nous présentons ici des spectres énergétiques des électrons créés au cours de l'explosion de feuilles minces par laser à haut flux à 03BB =1,06 03BCm, 03BB = 0,53 03BCm et à 03BB = 0,26 03BCm. Nous exposons les diagrammes angulaires électroniques à 03BB = 0,26 03BCm pour différentes énergies, caractérisés (au-dessus de 150 keV) par une structure piquée le long de l'axe laser. Ces électrons peuvent être en partie expliqués par leur accélération dans l'onde de plasma issue de l'instabilité Raman arrière..
Revue de Physique Appliquée, 1988
La production de champs électriques de très grande amplitude (~ GV/m) dans des plasmas par diffus... more La production de champs électriques de très grande amplitude (~ GV/m) dans des plasmas par diffusion Raman stimulée vers l'avant et l'accélération d'électrons jusqu'à des énergies de l'ordre du MeV ont été observées dans plusieurs expériences d'interaction laser-plasma. Nous étudions la recherche des conditions optimales pour que la diffusion Raman avant puisse se développer et domine les autres instabilités paramétriques, en particulier la rétrodiffusion Brillouin stimulée et la diffusion Raman arrière ; cette étude conduit à des lois d'échelle sur la longueur, la densité et la température électroniques du plasma. Les expériences utilisent le laser à néodyme du GRECO ILM à différentes longueurs d'onde et ont pour but l'étude de la diffusion Raman, la résolution spectrale et temporelle de son émission vers l'avant et vers l'arnère ainsi que l'analyse en énergie des électrons suprathermiques dans deux types de plasma.
Physics of Plasmas, 2002
ABSTRACT The structure of the wakefield is studied in a plasma column, created by a monomode lase... more ABSTRACT The structure of the wakefield is studied in a plasma column, created by a monomode laser pulse propagating in a capillary tube, filled with gas affected by tunneling ionization. Linear analytical considerations as well as self-consistent numerical simulations show that in the central bulk part of a plasma column where the laser intensity exceeds the ionization threshold, the wakefield structure is similar to that of an infinite homogeneous plasma. Near the wall of the capillary tube, where the laser intensity decreases below the ionization threshold and where the plasma density falls to zero, the curvature of the plasma wave phase front increases with the distance from the laser pulse, resulting in small-scale radial electric field which may undergo phase mixing. © 2002 American Institute of Physics.
Physica Scripta, 1994
The generation of high phase-velocity, large-amplitude plasma-wave using plasmas and either elect... more The generation of high phase-velocity, large-amplitude plasma-wave using plasmas and either electron beams or lasers is of fundamental interest for the field of particle accelerator physics. A review is made over the recently performed experiments: electron wake-field at Argone National Laboratory, laser beat-wave with CO2 lasers at I.N.R.S. and U.C.L.A., and with Nd-glass laser at Ecole Polytechnique. With both lasers, electric fields of the order of 1 GV/m have been detected. At U.C.L.A., injected electrons have been accelerated from 1.5 MeV to 10 MeV by the CO2 excited beat wave showing therefore the efficiency of the physical process. Promising photon wake-field experiments are also in preparation.
Journal de Physique III, 1991
The main features of a laboratory experiment devoted to the study of beam-plasma interactions are... more The main features of a laboratory experiment devoted to the study of beam-plasma interactions are described; the production and the principal characteristics of a magnetized plasma created by a steady state or pulsed discharge are presented; a description of the electron gun is given so as the first results concerning the injection of the monokinetic electron beam in the neutral Argon gas. Une expérience d'interaction d'un plasma magnétisé avec un faisceau d'électrons a été réalisée en vue d'applications en géophysique et en physique spatiale. Les caractéristiques du plasma et du faisceau sont présentées. Le plasma est produit en régime continu ou pulsé (densité n \cong 10^{12} e/cm^3, température T \cong 3 eV, champ magnétique B \cong 100 G). Le faisceau d'électrons (énergie E_b \cong 300 eV, intensité I_b \cong 10 mA) se propage à basse pression (P < 5 10^{-4} Torr) et interagit avec le plasma qu'il crée à pression plus élevée.
Journal de Physique, 1982
2014 Une théorie de diffusion ambipolaire permet d'établir l'équation différentielle à laquelle o... more 2014 Une théorie de diffusion ambipolaire permet d'établir l'équation différentielle à laquelle obéit la densité électronique d'un plasma collisionnel diffusant à travers un champ magnétique inhomogène. L'équation de diffusion est résolue numériquement dans une configuration de champ multipolaire, et le profil de potentiel est calculé. Nos résultats permettent d'interpréter le fait que les variations de la densité sont concentrées au voisinage de la paroi, ainsi que l'apparition de régions de potentiel élevé dans une décharge multipolaire. Abstract. 2014 Making use of an ambipolar diffusion theory, the differential equation governing the electronic density of a collisional plasma diffusing through an inhomogeneous magnetic field is established The diffusion equation is solved numerically in the case of a multipolar field and the profile of the potential is calculated. Our results enable us to interpret the fact that the density variations are located in the vicinity of the wall as well as the occurrence of high potential regions in a multipolar discharge. J. Physique 43 (1982) 67-75 JANVIER 1982, Classification Physics Abstracts 52.55K -52.50D
Physics of Fluids, 1976
The nonlinear growth and saturation of the nonresonant beat oscillation driven by two ion-acousti... more The nonlinear growth and saturation of the nonresonant beat oscillation driven by two ion-acoustic waves have been observed. After saturation, the beat signal relaxes into a resonant ion-acoustic wave.
Le Journal de Physique Colloques, 1971
Laser plasma interaction over many Rayleigh lengths is desirable for applications such as plasma ... more Laser plasma interaction over many Rayleigh lengths is desirable for applications such as plasma based accelerators, X ray lasers or fast ignitor concepts. A microcapillary tube can be used as a wave guide to propagate high laser intensities over lengths in the range of 10 th of cm. The conditions for monomode guiding of the laser, the damping length have been obtained analytically and verified i n experiments using one of the laser beam (30mJ, 120fs) of the Laboratoire d'Optique Appliquée facility.
Review of Scientific Instruments, 1990
This paper describes the techniques used to create a fully ionized plasma by the multiphoton ioni... more This paper describes the techniques used to create a fully ionized plasma by the multiphoton ionization of gases at pressures of a few Torr to give an initial electron density precision of better than a few percent, necessary for beat-wave experiments. A gas containment vessel has been constructed using high vacuum techniques with a temperature control system to maintain the
Physical Review Letters, 1975
Nonlinear damping of a broad-band spectrum of plasma waves has been observed. Frequencies lower t... more Nonlinear damping of a broad-band spectrum of plasma waves has been observed. Frequencies lower than the spectrum are growing from background noise. A shift of the entire spectrum towards lower frequencies results. The evolution of the spectrum is in good agreement with the predictions of weak-turbulence theory. Measurements of the electron velocity distribution are presented.
Laser and Particle Beams, 1991
AIP Conference Proceedings, 1999
The acceleration of electrons injected in a plasma wave generated by the laser wakeeld mechanism ... more The acceleration of electrons injected in a plasma wave generated by the laser wakeeld mechanism has been observed. A maximum energy gain of 1.6 MeV has been measured and the maximum longitudinal electric eld is estimated to 1.5 GV/m. The experimental data agree with theoretical predictions when 3D eects are taken into account. The duration of the plasma wave inferred from the number of accelerated electrons is of the order of 1 ps.
Physical Review E, 1998
This Rapid Communication deals with the electron-density measurements using the resonance cone ph... more This Rapid Communication deals with the electron-density measurements using the resonance cone phenomenon in a cold magnetized plasma. The collision frequency limits the modulus of the upper hybrid resonance cone peak and shifts it. Theoretically, this effect is slight and should not affect the electron-density measurements done with this method in magnetized plasmas. The experiment reported in this paper shows that the phenomenological collision frequency introduced in the theoretical potential is much higher than expected on the basis of electron-ion and electron-neutral collisions, so that it is necessary to examine not only the amplitude of the signal but also its phase, in order to estimate this phenomenological frequency and thus the correction to bring about the electron density.
Physics of Fluids B: Plasma Physics, 1993
Physics of Fluids B: Plasma Physics, 1992
ABSTRACT
Revue de Physique Appliquée, 1988
Nous présentons ici des spectres énergétiques des électrons créés au cours de l'explosion de feui... more Nous présentons ici des spectres énergétiques des électrons créés au cours de l'explosion de feuilles minces par laser à haut flux à 03BB =1,06 03BCm, 03BB = 0,53 03BCm et à 03BB = 0,26 03BCm. Nous exposons les diagrammes angulaires électroniques à 03BB = 0,26 03BCm pour différentes énergies, caractérisés (au-dessus de 150 keV) par une structure piquée le long de l'axe laser. Ces électrons peuvent être en partie expliqués par leur accélération dans l'onde de plasma issue de l'instabilité Raman arrière..
Revue de Physique Appliquée, 1988
La production de champs électriques de très grande amplitude (~ GV/m) dans des plasmas par diffus... more La production de champs électriques de très grande amplitude (~ GV/m) dans des plasmas par diffusion Raman stimulée vers l'avant et l'accélération d'électrons jusqu'à des énergies de l'ordre du MeV ont été observées dans plusieurs expériences d'interaction laser-plasma. Nous étudions la recherche des conditions optimales pour que la diffusion Raman avant puisse se développer et domine les autres instabilités paramétriques, en particulier la rétrodiffusion Brillouin stimulée et la diffusion Raman arrière ; cette étude conduit à des lois d'échelle sur la longueur, la densité et la température électroniques du plasma. Les expériences utilisent le laser à néodyme du GRECO ILM à différentes longueurs d'onde et ont pour but l'étude de la diffusion Raman, la résolution spectrale et temporelle de son émission vers l'avant et vers l'arnère ainsi que l'analyse en énergie des électrons suprathermiques dans deux types de plasma.
Physics of Plasmas, 2002
ABSTRACT The structure of the wakefield is studied in a plasma column, created by a monomode lase... more ABSTRACT The structure of the wakefield is studied in a plasma column, created by a monomode laser pulse propagating in a capillary tube, filled with gas affected by tunneling ionization. Linear analytical considerations as well as self-consistent numerical simulations show that in the central bulk part of a plasma column where the laser intensity exceeds the ionization threshold, the wakefield structure is similar to that of an infinite homogeneous plasma. Near the wall of the capillary tube, where the laser intensity decreases below the ionization threshold and where the plasma density falls to zero, the curvature of the plasma wave phase front increases with the distance from the laser pulse, resulting in small-scale radial electric field which may undergo phase mixing. © 2002 American Institute of Physics.