Development of resonant diplexers for high-power ECRH - Status, applications, plans

W. Kasparek, B. Plaum, C. Lechte, Z. Wu, H. Wang, M. Maraschek, J. Stober, D. Wagner, M. Reich, M. Schubert, G. Grünwald, F. Monaco, S. Müller, H. Schütz, V. Erckmann, N. Doelman, R. Van Den Braber, W. Klop, H. Van Den Brand, W. BongersB. Krijger, M. Petelin, E. Koposova, L. Lubyako, A. Bruschi, K. Sakamoto

Research output: Contribution to conferencePaper

4 Citations (Scopus)

Abstract

The development of diplexers for ECRH has been pursued at a number of institutes because of their attractive variety of applications: Power combination, non-mechanical, electrically controlled switching (of combined beams) between launchers with tens of kHz, and discrimination of low-power ECE signals from high-power ECRH is feasible. In a first part, this paper reports on plasma experiments with a ring resonator (Mk IIa) at ASDEX Upgrade. Commissioning experiments on fast switching between two launchers for synchronous stabilization of neoclassical tearing modes, as well as in-line ECE measurements have been performed, and experimental issues and first results are discussed. A clear influence of the switching phase on the amplitude of the 3/2 NTM mode was measured, complete stabilization could, however, not be demonstrated yet mainly due to imperfect resonator control. Concepts for improved tracking of the diplexers to the gyrotron frequency are presented. In a second part, the design of diplexers with ring resonators matched to HE11 fields is briefly discussed; these devices can be connected to corrugated waveguides without any mode converters. A compact version (MQ IV) is under investigation, which is compatible with the ITER ECRH system (170 GHz, 63.5 mm waveguide, vacuum tight casing), with the final goal of high-power tests at the 170 GHz gyrotron facility at JAEA in Naka, Japan. First low-power test results are presented.
Original languageEnglish
DOIs
Publication statusPublished - 12 Mar 2015
Externally publishedYes
Event18th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating, EC 2014 - Nara, Japan
Duration: 12 Mar 2015 → …

Conference

Conference18th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating, EC 2014
CountryJapan
CityNara
Period12/3/15 → …

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All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Kasparek, W., Plaum, B., Lechte, C., Wu, Z., Wang, H., Maraschek, M., ... Sakamoto, K. (2015). Development of resonant diplexers for high-power ECRH - Status, applications, plans. Paper presented at 18th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating, EC 2014, Nara, Japan. https://doi.org/10.1051/epjconf/20158704010