Towards Control of Steady State Plasma on Tore Supra

The Tore Supra tokamak is the largest superconducting magnetic fusion facility, has been devoted to long-duration high-performance discharge research. With a steady-state magnetic field and water cooled plasma facing components, discharges up to 6 minutes 24 seconds duration with injected / extracted energy up to 1 GJ have been performed. The Tore Supra real time measurements and control (RTMC) system has been upgraded to address schemes dedicated to long pulse operation with simultaneous control of an increasing number of plasma parameters. This includes plasma equilibrium control with possible self calibration during the discharge, plasma density control with possible pellet injection, current profile control to avoid magneto-hydrodynamic (MHD) instabilities and infrared monitoring of plasma facing components preventing overheating. Most of these improvements are relevant to the tokamaks operation in a fully steady state regime

The CEDRES++ equilibrium code and its application to ITER, JT-60SA and Tore Supra.

International audienceFree-boundary equilibrium codes are an essential tool for tokamak design studies and scenario development. In this contribution, the CEDRES++ code is presented and applications to ITER, JT-60SA and Tore Supra are reported on. A satisfactory benchmark of CEDRES++ with the DINA code was performed on an ITER Scenario 2 case at 32 different times across the discharge, both in direct and inverse mode. Ongoing design studies for the poloidal field coils system of JT-60SA, performed in the frame of the Broader Approach,werecross checkedwithCEDRES++.Finally,adimensioningstudywascarriedoutforthecoils and power supplies for plasma vertical control in the frame of a feasibility study for the implementation of a divertor in Tore Supr

Self-consistent hydrogen isotopes recycling model for the SolEdge2D-EIRENE transport code

International audienc

Density regimes and heat flux deposition in the WEST shallow divertor configuration

International audienceTo support ITER divertor design, the WEST project on Tore Supra aims at studying high heat fluxes on tungsten monoblock during long pulses. In that persective, a particular attention is paid to simulate the edge plasma interaction with complex PFCs using the transport code SOLEDGE2D-EIRENE. The plasma response to a heating and puffing scenario is described as well as the so-called divertor density regimes, characterizing the operational domain of the WEST divertor. These results are compared for two different magnetic configurations: a semi-open double null divertor with the X-point away from the target plates and a shallow divertor configuration with the X-point close to the targets

Numerical modelling for divertor design of the WEST device with a focus on plasma–wall interactions

International audienceIn the perspective of operating tungsten monoblocks in WEST, the ongoing major upgrade of the Tore Supra tokamak, a dedicated modelling effort has been carried out to simulate the interaction between the edge plasma and the tungsten wall. A new transport code, SolEdge2D–EIRENE, has been developed with the ability to simulate the plasma up to the first wall. This is especially important for steady state operation, where thermal loads on all the plasma facing components, even remote from the plasma, are of interest. Moreover, main chamber tungsten sources are thought to dominate the contamination of the plasma core. We present here in particular new developments aimed at improving the description of the interface between the plasma and the wall, namely a way to treat sheath physics in a more faithful way using the output of 1D particle in cell simulations. Moreover, different models for prompt redeposition have been implemented and are compared. The latter is shown to play an important role in the balance between divertor and main chamber sources

Comparison on heat flux deposition between carbon and tungsten wall – Investigations on energy recycling

International audienceThe influence of the plasma facing components material on the scrape-off layer plasma is investigated. In particular, the energy recycling is found to be more pronounced for tungsten wall compared with carbon wall. Edge plasma simulations performed with the transport code SOLEDGE2D-EIRENE show that this enhanced energy recycling in the tungsten case leads to an increase of the scrape-off layer temperature. Moreover, the energy recycling depends on the ion angle of incidence with the wall. A PIC code has been used to model the ion acceleration in the magnetic pre-sheath and determine the later angle of incidence. These simulations show that ions mostly impact the wall with rather shallow incident angles leading to a further increase of the energy recycling

Real-Time SER measurements of CMOS Bulk 40 nm and 65 nm SRAMs combined with neutron spectrometry at the JET Tokamak during D-D and D-T plasma operation

International audienceWe performed SER characterization of decananometer SRAMs combined with neutron spectrometry in the deuterium-tritium-fueled JET tokamak, demonstrating the impact of machine operation on the reliability of electronics in conditions approaching those of future fusion reactors