Development of glow discharge and electron cyclotron resonance heating conditioning on W7-X

Bibliographic Details
Title: Development of glow discharge and electron cyclotron resonance heating conditioning on W7-X
Authors: A. Goriaev, T. Wauters, R. Brakel, H. Grote, M. Gruca, O. Volzke, S. Brezinsek, A. Dinklage, M. Kubkowska, U. Neuner
Source: Nuclear Materials and Energy, Vol 18, Iss , Pp 227-232 (2019)
Publisher Information: Elsevier, 2019.
Publication Year: 2019
Collection: LCC:Nuclear engineering. Atomic power
Subject Terms: Nuclear engineering. Atomic power, TK9001-9401
More Details: For successful operation of Wendelstein 7-X (W7-X) control of plasma impurity content and fuel recycling is required. This can be achieved by using wall conditioning methods. During the first divertor operation campaign (OP1.2a) of W7-X glow discharge conditioning (GDC), weekly in hydrogen and daily in helium for impurity and hydrogen removal respectively, was used in the absence of the magnetic field. He electron cyclotron resonance heating (ECRH) discharges were applied for density control in hydrogen plasmas during experimental days. The optimization of GDC and He ECRH wall conditioning on W7-X are presented. Solutions for glow discharge ignition problems are examined. The suitable He – GDC parameters, i.e. anode current and neutral gas pressure, are defined to keep the balance between maximum possible hydrogen removal rate and minimum plasma – facing component (PFC) erosion. Sequences of short He – ECRH pulses, so-called pulse trains, has been successfully implemented. The effect of pulse train main parameter variation such as gas prefill, input power, pulse length, duty cycle is described. The efficiency of single He recovery discharges and pulse trains are compared. The results of this work show significant improvement of wall cleaning efficiency. Keywords: W7-X, Wall conditioning, GDC, ECRH, Pulse train, Recovery discharge
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2352-1791
Relation: http://www.sciencedirect.com/science/article/pii/S2352179118302059; https://doaj.org/toc/2352-1791
DOI: 10.1016/j.nme.2018.12.010
Access URL: https://doaj.org/article/924cd984e68f4dc2b7a9358561b41d8a
Accession Number: edsdoj.924cd984e68f4dc2b7a9358561b41d8a
Database: Directory of Open Access Journals
More Details
ISSN:23521791
DOI:10.1016/j.nme.2018.12.010
Published in:Nuclear Materials and Energy
Language:English