Philippe Marmillod - Academia.edu (original) (raw)
Uploads
Papers by Philippe Marmillod
Fusion Engineering and Design, 2015
Fusion Engineering and Design, 2015
Fusion Engineering and Design, 2013
h i g h l i g h t s
Fusion Engineering and Design, 2007
In the frame of the EU program on the ITER Electron Cyclotron Wave (ECW) system, the development ... more In the frame of the EU program on the ITER Electron Cyclotron Wave (ECW) system, the development of a 170 GHz, 2 MW CW coaxial gyrotron with depressed collector (C-GT170) has been launched during the 6 th Framework Program (2003)(2004)(2005)(2006) in the European Technology Workplan. Such development relies on the availability of a Test Facility (TF) capable of providing both the energy sources and sinks required by this new electron tube (electrical energy, cooling capacity), and allowing the control and acquisition of a large range of signals used to understand and improve the gyrotron behaviour. The TF will be used, in a later stage, for the component test of the ITER ECW system. This paper will report on the design, installation and commissioning of the TF in Lausanne.
Seventh Conference Real Time '91 on Computer Applications in Nuclear, Particle and Plasma Physics Conference Record, 1991
ABSTRACT
... M Anton, H Weisen, MJ Dutch, W von der Linden, F Buhlmann, R Chavan, B Marletaz, P Mar... more ... M Anton, H Weisen, MJ Dutch, W von der Linden, F Buhlmann, R Chavan, B Marletaz, P Marmillod and P Paris Centre de Recherches en Physique des Plasmas, Association EURATOM Confédération Suisse, Ecole Polytechnique Fédérale de Lausanne, CH ...
ABSTRACT TCV has the highest power (3MW in X2 and 1.5MW in X3, 2.0s) and most ITER-relevant ECH s... more ABSTRACT TCV has the highest power (3MW in X2 and 1.5MW in X3, 2.0s) and most ITER-relevant ECH system in the world today, owing to its real-time poloidal and toroidal steerable mirrors. This paper summarizes recent TCV discharges using ECH. In non-inductive discharges, the co-ECCD deposition was placed off-axis creating a large bootstrap fraction and a flat or slightly reversed shear current profile, even though the EC driven current is peaked or only slightly hollow due to radial diffusion. After reaching equilibrium, on-axis counter-ECCD was injected enhancing the reversed shear by increasing the bootstrap fraction ( 80%) and rapidly increasing the confinement time (tau_e), a factor of 1.6 over ITER L-mode scaling. The ITB is generated in stationary conditions and is sustained for 10 times the current redistribution time. Experimental results have shown that the improved taue is directly related to the degree of reverse shear in the center. In particular, the electron temperature and pressure profiles are controlled by the amount of counter-ECCD on axis, and in particular the gradients can be tuned to be marginally MHD stable. No power threshold for the ITB formation is observed. In other discharges the sawteeth are de-stabilized (stabilized) when heating just inside (outside) the q=1 surface. Control of the sawteeth allows the avoidance of NTMs that are otherwise seeded by the sawtooth instability. A transport code linked to a sawtooth model reproduces the variation in sawtooth period with the EC deposition location. Finally, preliminary results with the X3 top-launch have shown 70% single-pass absorption with 0.9MW and densities up to 0.5 10^20m-3 in good agreement with the absorption calculated by a linear ray tracing code.
A new toroidal device, TORPEX, is under construction at CRPP-EPFL to investigate basic collisionl... more A new toroidal device, TORPEX, is under construction at CRPP-EPFL to investigate basic collisionless plasma phenomena, including wave-particle interaction, transport processes and magnetic reconnection. Major and minor radius are R=1m and a=0.2m. The toroidal magnetic field is of the order of 0.1T. A poloidal coil system can generate magnetic field from purely vertical to a cusp configuration. Different plasma production
ECRH and ECCD, disruptive events, and sawtooth activity have been demonstrated to produce suprath... more ECRH and ECCD, disruptive events, and sawtooth activity have been demonstrated to produce suprathermal electrons in fusion devices, motivating increasingly detailed studies of the generation and dynamics of this suprathermal population. Past hard-X-ray (HXR) and ECE measurement in the TCV tokamak, which is equipped by a 4.5-MW ECRH system, have led to the identification of the crucial role of spatial
Fusion Engineering and Design, 2015
Fusion Engineering and Design, 2015
Fusion Engineering and Design, 2013
h i g h l i g h t s
Fusion Engineering and Design, 2007
In the frame of the EU program on the ITER Electron Cyclotron Wave (ECW) system, the development ... more In the frame of the EU program on the ITER Electron Cyclotron Wave (ECW) system, the development of a 170 GHz, 2 MW CW coaxial gyrotron with depressed collector (C-GT170) has been launched during the 6 th Framework Program (2003)(2004)(2005)(2006) in the European Technology Workplan. Such development relies on the availability of a Test Facility (TF) capable of providing both the energy sources and sinks required by this new electron tube (electrical energy, cooling capacity), and allowing the control and acquisition of a large range of signals used to understand and improve the gyrotron behaviour. The TF will be used, in a later stage, for the component test of the ITER ECW system. This paper will report on the design, installation and commissioning of the TF in Lausanne.
Seventh Conference Real Time '91 on Computer Applications in Nuclear, Particle and Plasma Physics Conference Record, 1991
ABSTRACT
... M Anton, H Weisen, MJ Dutch, W von der Linden, F Buhlmann, R Chavan, B Marletaz, P Mar... more ... M Anton, H Weisen, MJ Dutch, W von der Linden, F Buhlmann, R Chavan, B Marletaz, P Marmillod and P Paris Centre de Recherches en Physique des Plasmas, Association EURATOM Confédération Suisse, Ecole Polytechnique Fédérale de Lausanne, CH ...
ABSTRACT TCV has the highest power (3MW in X2 and 1.5MW in X3, 2.0s) and most ITER-relevant ECH s... more ABSTRACT TCV has the highest power (3MW in X2 and 1.5MW in X3, 2.0s) and most ITER-relevant ECH system in the world today, owing to its real-time poloidal and toroidal steerable mirrors. This paper summarizes recent TCV discharges using ECH. In non-inductive discharges, the co-ECCD deposition was placed off-axis creating a large bootstrap fraction and a flat or slightly reversed shear current profile, even though the EC driven current is peaked or only slightly hollow due to radial diffusion. After reaching equilibrium, on-axis counter-ECCD was injected enhancing the reversed shear by increasing the bootstrap fraction ( 80%) and rapidly increasing the confinement time (tau_e), a factor of 1.6 over ITER L-mode scaling. The ITB is generated in stationary conditions and is sustained for 10 times the current redistribution time. Experimental results have shown that the improved taue is directly related to the degree of reverse shear in the center. In particular, the electron temperature and pressure profiles are controlled by the amount of counter-ECCD on axis, and in particular the gradients can be tuned to be marginally MHD stable. No power threshold for the ITB formation is observed. In other discharges the sawteeth are de-stabilized (stabilized) when heating just inside (outside) the q=1 surface. Control of the sawteeth allows the avoidance of NTMs that are otherwise seeded by the sawtooth instability. A transport code linked to a sawtooth model reproduces the variation in sawtooth period with the EC deposition location. Finally, preliminary results with the X3 top-launch have shown 70% single-pass absorption with 0.9MW and densities up to 0.5 10^20m-3 in good agreement with the absorption calculated by a linear ray tracing code.
A new toroidal device, TORPEX, is under construction at CRPP-EPFL to investigate basic collisionl... more A new toroidal device, TORPEX, is under construction at CRPP-EPFL to investigate basic collisionless plasma phenomena, including wave-particle interaction, transport processes and magnetic reconnection. Major and minor radius are R=1m and a=0.2m. The toroidal magnetic field is of the order of 0.1T. A poloidal coil system can generate magnetic field from purely vertical to a cusp configuration. Different plasma production
ECRH and ECCD, disruptive events, and sawtooth activity have been demonstrated to produce suprath... more ECRH and ECCD, disruptive events, and sawtooth activity have been demonstrated to produce suprathermal electrons in fusion devices, motivating increasingly detailed studies of the generation and dynamics of this suprathermal population. Past hard-X-ray (HXR) and ECE measurement in the TCV tokamak, which is equipped by a 4.5-MW ECRH system, have led to the identification of the crucial role of spatial