Publications by Trach-Minh Tran

Overview on recent progress in magnetron injection gun theory and design for high power gyrotrons

Stefano Alberti, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Ioannis Pagonakis, Jérémy Genoud, Konstantinos Avramidis

The magnetron injection gun (MIG) is one of the most critical subcomponents in gyrotrons. The electron beam, which has the primary role on the gyrotron operation, is generated and configured at this part of the tube. The electron beam properties determine ...

E D P SCIENCES2019

Parasitic Oscillations in Smooth-Wall Circular Symmetric Gyrotron Beam Ducts

Stefano Alberti, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Jérémy Genoud, Konstantinos Avramidis

In order to study parasitic oscillation that may occur in a realistic beam duct upstream to the gyrotron cavity, the self-consistent linear and spectral code TWANGlinspec has been modified. The large inhomogeneities in the smooth-wall beam duct geometry or ...

2018

An arbitrary wavelength solver for global gyrokinetic simulations. Application to the study of fine radial structures on microturbulence due to non-adiabatic passing electron dynamics

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Ben McMillan, Julien Stanislas Pierre Dominski, Gabriele Merlo

The influence of the fine layers of the non-adiabatic passing electron response on electrostatic turbulent transport, previously studied systematically in flux tube geometry [Dominski et al., Phys. Plasmas 22, 062303 (2015)], is pursued in global geometry ...

Amer Inst Physics2017

Collisional damping rates for electron plasma waves reassessed

Stephan Brunner, Trach-Minh Tran

Collisional damping of electron plasma waves, the primary damping for high phase velocity waves, is proportional to the electron-ion collision rate, nu(ei,th). Here, it is shown that the damping rate normalized to nu(ei,th) depends on the charge state, Z, ...

Amer Physical Soc2017

Linear and non-linear studies of spurious backward-wave instabilities in a smooth-wall gyrotron beam duct

Stefano Alberti, Trach-Minh Tran, Jérémy Genoud

Recently developed self-consistent models for beam-wave interaction simulations of a gyrotron oscillator are used to study spurious backward-wave instabilities in smooth-wall metallic beam ducts. Starting from a simple case with a basic geometry, the influ ...

2017

Vlasov simulations of electron-ion collision effects on damping of electron plasma waves

Stephan Brunner, Trach-Minh Tran

Collisional effects can play an essential role in the dynamics of plasma waves by setting a minimum damping rate and by interfering with wave-particle resonances. Kinetic simulations of the effects of electron-ion pitch angle scattering on Electron Plasma ...

Amer Inst Physics2016

Novel linear analysis for a gyrotron oscillator based on a spectral approach

Stefano Alberti, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Jérémy Genoud

With the aim of gaining a better physical insight into linear regimes in gyrotrons, a new linear model was developed. This model is based on a spectral approach for solving the self-consistent system of equations describing the wave-particle interaction in ...

American Institute of Physics (AIP)2016

Start-up scenario studies in gyrotron oscillator using a novel linear and spectral code

Stefano Alberti, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Jérémy Genoud

A linear and spectral model has recently been developed [1], describing the self-consistent wave-particle interaction in a gyrotron oscillator. The spectral approach, compared to commonly used time-evolution approaches, has the possibility to describe all ...

IEEE2016

The GBS code for tokamak scrape-off layer simulations

Trach-Minh Tran, Sébastien Jolliet, Joaquim Loizu Cisquella, Paolo Ricci, Fabio Riva, Annamaria Mosetto, Federico David Halpern, Christoph Wersal

We describe a new version of GBS, a 3D global, flux-driven plasma turbulence code to simulate the turbulent dynamics in the tokamak scrape-off layer (SOL), superseding the code presented by Ricci et al. (2012) [14]. The present work is driven by the object ...

Elsevier2016

A portable platform for accelerated PIC codes and its application to GPUs using OpenACC

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Emmanuel Lanti, Claudio Gheller

We present a portable platform, called PIC_ENGINE, for accelerating Particle-In-Cell (PIC) codes on heterogeneous many-core architectures such as Graphic Processing Units (GPUs). The aim of this development is efficient simulations on future exascale syste ...

Elsevier Science Bv2016

Towards the optimization of a gyrokinetic Particle-In-Cell (PIC) code on large-scale hybrid architectures

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Emmanuel Lanti, Noé Thomas Elie Ohana, Claudio Gheller

With the aim of enabling state-of-the-art gyrokinetic PIC codes to benefit from the performance of recent multithreaded devices, we developed an application from a platform called the "PIC-engine" [1, 2, 3] embedding simplified basic features of the PIC me ...

2016

Saturated ideak kink/peeling formations described as three-dimensional magnetohydrodynamic tokamak equilibrium states

Wilfred Anthony Cooper, Basil Duval, Olivier Sauter, Trach-Minh Tran, Holger Reimerdes, Laurie Porte, Jonathan Graves, David Pfefferlé, Daniele Brunetti, Andreas Kleiner, Jonathan Marc Philippe Faustin, Madhusudan Raghunathan, Hamish William Patten

Free boundary magnetohydrodynamic equilibrium states with spontaneous three dimensional deformations of the plasma-vacuum interface are computed for the first time. The structures obtained have the appearance of saturated ideal external kink/peeling modes. ...

American Institute of Physics (AIP)2016

Three-dimensional magnetohydrodynamic equilibrium of quiescent H-modes in tokamak systems

Wilfred Anthony Cooper, Basil Duval, Olivier Sauter, Trach-Minh Tran, Jonathan Graves, Andreas Kleiner, Jonathan Marc Philippe Faustin, Madhusudan Raghunathan, Hamish William Patten, Samuel Lanthaler

Three dimensional free boundary magnetohydrodynamic equilibria that recover saturated ideal kink/peeling structures are obtained numerically. Simulations that model the JET tokamak at fixed = 1.7% with a large edge bootstrap current that flattens t ...

IOP Publishing2016

A bucket sort algorithm for the particle-in-cell method on manycore architectures

Stephan Brunner, Trach-Minh Tran, Laurent Villard, Claudio Gheller

The Particle-In-Cell (PIC) method is effectively used in many scientific simulation codes. In order to optimize the performance of the PIC approach, data locality is required. This relies on efficient sorting algorithms. We present a bucket sort algorithm ...

Springer2016

Progress on the upgrade of the TCV EC-system with two 1MW dual-frequency gyrotrons

Stefano Alberti, Timothy Goodman, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Ioannis Pagonakis, Jérémy Genoud, Konstantinos Avramidis

The upgrade of the electron cyclotron (EC) system of the TCV tokamak has entered in its realization phase. The MW-class dual-frequency gyrotron design (84 or 126GHz/2s), based on the 140GHz W7-X gyrotron, is finalized and a contract for the manufacturing o ...

IEEE2016

A 3D MHD equilibrium description of nonlinearly saturated ideal external kink/peeling structures in tokamaks

Wilfred Anthony Cooper, Basil Duval, Olivier Sauter, Trach-Minh Tran, Holger Reimerdes, Laurie Porte, Jonathan Graves

Novel free boundary magnetohydrodynamic equilibrium states with spontaneous three-dimensional (3-D) deformations of the plasmaâ vacuum interface are computed. The structures obtained look like saturated ideal external kink/peeling modes. Large edge pre ...

Cambridge University Press2015

Status of the development of the EU 170 GHz/1 MW/CW gyrotron

Stefano Alberti, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Christian Schlatter, Ioannis Pagonakis, Konstantinos Avramidis

The progress in the development of the European 170 GHz, 1 MW/CW gyrotron for electron cyclotron heating & current drive (ECH&CD) on ITER is reported. A continuous wave (CW) prototype is being manufactured by Thales Electron Devices (TED), France, while a ...

Elsevier Science Sa2015

Generalized radiation boundary conditions in gyrotron oscillator modeling

Stephan Brunner, Stefano Alberti, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Jérémy Genoud

A numerical procedure to implement a frequency-independent generalized non-reflecting radiation boundary conditions, GNRBC, based on the Laplace Transform, is described in details and tested successfully on a simple 2 frequency test problem. In the case of ...

Springer2015

TWANG-PIC, a novel gyro-averaged one-dimensional particle-in-cell code for interpretation of gyrotron experiments

Stefano Alberti, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Jérémy Genoud

A new gyrotron simulation code for simulating the beam-wave interaction using a monomode time-dependent self-consistent model is presented. The new code TWANG-PIC is derived from the trajectory-based code TWANG by describing the electron motion in a gyro-a ...

Amer Inst Physics2015

Novel self-consistent linear theory of a gyrotron oscillator and experimental validation

Stefano Alberti, Minh Quang Tran, Trach-Minh Tran, Jean-Philippe Hogge, Jérémy Genoud

2015