skip to main content

SciTech ConnectSciTech Connect

Title: Study and design of the ion cyclotron resonance heating system for the stellarator Wendelstein 7-X

The current status of the mechanical and electromagnetic design for the ICRF antenna system for W7-X is presented. Two antenna plugins are discussed: one consisting of a pair of straps with pre-matching to cover the first frequency band, 25–38 MHz, and a second one consisting of two short strap triplets to cover a frequency band around 76 MHz. This paper focusses on the two strap antenna for the lower frequency band. Power coupling of the antenna to a reference plasma profile is studied with the help of the codes TOPICA and Microwave Studio that deliver the scattering matrix needed for the optimization of the geometric parameters of the straps and antenna box. Radiation power spectra for different phasings of the two straps are obtained using the code ANTITER II and different heating scenario are discussed. The potential for heating, fast particle generation, and current drive is discussed. The problem of RF coupling through the plasma edge and of edge power deposition is summarized. Important elements of the complete ion cyclotron resonance heating system are discussed: a resonator circuit with tap feed to limit the maximum voltage in the system, and a decoupler to counterbalance the large mutual coupling between themore » 2 straps. The mechanical design highlights the challenges encountered with this antenna: adaptation to a large variety of plasma configurations, the limited space within the port to accommodate the necessary matching components and the watercooling needed for long pulse operation.« less
Authors:
; ; ; ; ; ; ; ; ; ; ; ; ;  [1] ; ; ;  [2] ;  [3] ; ;  [4] more »; « less
  1. Laboratory for Plasmaphysics, Ecole Royale Militaire–Koninklijke Militaire School, TEC Partner, Brussels (Belgium)
  2. IEK-4/Plasmaphysik, Forschungszentrum Juelich, TEC Partner, Juelich (Germany)
  3. ZEA-1, Forschungszentrum Juelich, Juelich (Germany)
  4. Max-Planck Institute für Plasmaphysik, Teilinstitut Greifswald, Greifswald (Germany)
Publication Date:
OSTI Identifier:
22299957
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 6; Other Information: (c) 2014 EURATOM; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANTENNAS; DESIGN; HEATING SYSTEMS; ICR HEATING; ION CYCLOTRON-RESONANCE; MHZ RANGE 01-100; MICROWAVE RADIATION; OPTIMIZATION; PLASMA RADIAL PROFILES; STELLARATORS