New linear plasma devices in the trilateral euregio cluster for an integrated approach to plasma surface interactions in fusion reactors

New linear plasma devices are currently being constructed or planned in the Trilateral Euregio Cluster (TEC) to meet the challenges with respect to plasma surface interactions in DEMO and ITER: i) MAGNUM-PSI (FOM), a high particle and power flux device with super-conducting magnetic field coils which will reach ITER-like divertor conditions at high magnetic field, ii) the newly proposed linear plasma device JULE-PSI (FZJ), which will allow to expose toxic and neutron activated target samples to ITER-like fluences and ion energies including in vacuo analysis of neutron activated samples, and iii) the plasmatron VISION I. a compact plasma device which will be operated inside the tritium lab at SCK-CEN Mol, capable to investigate tritium plasmas and moderately activated wall materials. This contribution shows the capabilities of the new devices and their forerunner experiments (Pilot-PSI at FOM and PSI-2 Julich at FZJ) in view of the main objectives of the new TEC program on plasma surface interactions. (C) 2011 Forschungszentrum Julich, Institut fur Energieforschung-Plasmaphysik. Published by Elsevier B.V. All rights reserved

Risk mitigation strategy for the ITER electron cyclotron upper port launcher

A basic requirement for ITER equipment to meet is a high level of reliability, because ITER operation time is precious and radioactive operation leaves limited scope for repair. In order to reduce the risk of failure during ITER operation an effective risk mitigation strategy is necessary. This paper presents such strategy for the ITER electron cyclotron upper port launcher (ECUPL). A preliminary ECUPL risk analysis identifies possible failure modes. A probabilistic risk assessment quantifies the risk of failure using a 4 x 4 impact-likelihood matrix. Impact is quantified through technical, cost and schedule elements. Likelihood depends on the risk mitigation strategy adopted. A cost benefit analysis determines the most cost effective risk mitigation strategy. An essential element in risk mitigation is the testing of equipment prior to installation on the ITER machine. This paper argues the need for low- and highpower millimetre wave tests carried out on the fully assembled ECUPL It presents a conceptual design for a dedicated on-site test bed that can handle 2 of 8 microwave beams at 2 MW long pulse operation. (C) 2010 Elsevier B.V. All rights reserved

Finalization of the conceptual design of the remote steering ECH launcher for ITER

The design of a remote steering (RS) variant of the electron cyclotron heating (ECH) upper port launcher (UPL) for neo-classical tearing mode (NTM) stabilization in ITER is being finalised. The RS variant is the fall-back option for the reference design, which is a front steering (FS) UPL. This paper presents the changes made in the design of the RS UPL with respect to the previous baseline (the October 2005 baseline) design. The changes are motivated by a demand to improve the reliability of the launching system by solving a number of pressing issues. To accomplish this, a reduction in the steering range of the launcher was proposed. This reduction yields more tolerable head loads on the focusing elements for a given performance. Modifications of the launcher layout allow for an increase of the toroidal injection angle, which improves the NTM stabilization efficiency. A mode converter can reduce the stray radiation in the vicinity of the steering mechanism down to tolerable levels. Abandoning the concept of the mini-duct leads to a reduction of stray radiation concerns and allows for the implementation of improved alignment facilities of the individual steerable mirror units. The work shows that a launcher based on the RS principle is feasible. This launcher can be made reliable, flexible and easily accessible for maintenance purposes accepting the consequent limitations in the achievable steering range inside the ITER plasma. (C) 2009 Elsevier B.V. All rights reserved

Production of solar fuels by CO2 plasmolysis

A storage scheme for Renewable Energy (RE) based on the plasmolysis of CO2into CO and O2 has been experimentally investigated, demonstrating high energy efficiency (>50%) combined with high energy density, rapid start-stop and no use of scarce materials. The key parameter controlling energy efficiency has been identified as the reduced electric field. Basic plasma parameters including density and temperature are derived from a simple particle and energy balance model, allowing parameter specification of an upscale 100 kW reactor. With RE powered plasmolysis as the critical element, a CO2 neutral energy system becomes feasible when complemented by effective capture of CO2 at the input and separation of CO from the output gas stream followed by downstream chemical processing into hydrocarbon fuels