[{"type":"speech","title":"Advanced gyrotron collector sweeping with smooth power distribution","issued":{"date-parts":[["2007"]]},"author":[{"family":"Erckmann","given":"V."},{"family":"Schmid","given":"M."},{"family":"Laqua","given":"H. P."},{"family":"Dammertz","given":"G."},{"family":"Illy","given":"S."},{"family":"Braune","given":"H."},{"family":"Hollmann","given":"F."},{"family":"Kasparek","given":"W."},{"family":"Michel","given":"G."},{"family":"Noke","given":"F."},{"family":"Purps","given":"F."},{"family":"ECRH Groups at IPP Greifswald","given":"F. Z. K Karlsruhe and I. P. F Stuttgart"}],"note":"4th IAEA Technical Meeting on ECRH Physics and Technology for ITER, Wien, A, June 6-8, 2007 Proc.on CD-ROM","abstract":"\u00a0\n\u00a0\n## \u00a0\n\u00a0\n## V. Erckmann1, M. Schmid2, H.P. Laqua1, G. Dammertz2, S. Illy2, H. Braune1, F. Hollmann1,\nECRH groups at IPP Greifswald1, FZK Karlsruhe2, and IPF Stuttgart1.\n\u00a0\n\u00a0\n\u00a0\nPresent day high power cw gyrotrons operate with an rf-power of typically 1 MW and efficiencies of 35-50 % [1,2], thus typically 1-2 MW power remains in the spent electron-beam and must be dumped in the gyrotron-collector. Vertical magnetic Field Sweeping (VFS) is a well established method and commonly used to bring the local collector power density down to acceptable values. A less established method is \u0091Transverse Field Sweeping\u0092 (TFS), which was invented in Russia [3] and further investigated at FZK [4].\u00a0 TFS proved to have a power capability comparable to VFS. The electron beam power distribution obtained with either method, however, shows pronounced maxima and the collectors operate at the technical limits. As these maxima determine the overall collector capability, we have investigated a new collector sweeping method, which generates a homogenous power deposition profile thus enhancing the total heat load capability of state of the art collectors significantly. The experiments were performed using a commercial THALES Gyrotron TH 1507 (140 GHz, 1 MW, cw), the results are reported. The application of the new sweeping method may be attractive for existing tubes, because they can be operated with higher safety margin (higher lifetime), as well as for future ITER gyrotrons with higher rf-power (towards 2 MW), because existing collector designs may already satisfy the additional power demands.\n\u00a0\n\u00a0\n[1] \u00a0\u00a0\u00a0 G. Dammertz, S. Alberti, A. Arnold, E. Borie, et al., IEEE Trans. Plasma Science 30 (2002) 808-818\n[2] \u00a0\u00a0\u00a0 K. Felch, M. Blank, P. Borchard, P. Cahalan, S. Cauffman, T.S. Chu and H. Jory,\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Journal of Physics:\u00a0 Conference Series 25 (2005) pp. 13-23.\n[3]\u00a0\u00a0\u00a0\u00a0 private communication\n[4] \u00a0\u00a0\u00a0 M. Schmid, S. Illy, G. Dammertz, V. Erckmann, M. Thumm:\nTransverse Field Collector Sweep System for high power CW Gyrotrons,\nto be published in Fusion Science and Technology\n\u00a0","kit-publication-id":"240067699"}]