NDLI: Progress of high power gyrotron development in JAEA

Content Provider	IEEE Xplore Digital Library
Author	Sakamoto, K. Kasugai, A. Kajiwara, K. Takahashi, K. Kobayashi, N. Oda, Y.
Copyright Year	2008
Description	Author affiliation: Japan Atomic Energy Agency, Naka (Sakamoto, K.; Kasugai, A.; Kajiwara, K.; Takahashi, K.; Kobayashi, N.; Oda, Y.)
Abstract	A 1 MW 170 GHz long pulse gyrotron is required for a power source of the electron cyclotron heating and current drive (EC H&CD) system on ITER (International Thermonuclear Experimental Reactor). In the ITER gyrotron development of JAEA (Japan Atomic Energy Agency), a stable 1 MW 170 GHz oscillation has been achieved at CW-relevant pulse duration (800 s), which is a twice of burning time of ITER plasma. The efficiency was 55% with the depressed collector with the precise optimization of the oscillation parameters in the hard self-excitation region during the oscillation. The power balance is measured calorimetrically, i.e., output power from the window is 1020 kW, power deposition to the collector is 742 kW, and a stray radiation output from the relief windows is 24 kW. Total ohmic-loss power into the inner components of the gyrotron is 63 kW. The power dissipation at the cavity agreed with the design value. The attained maximum efficiency in the long pulse mode is ~60%. The gyrotron has been working since March 2006 without major trouble, and records ~150 GJ of the output energy. The results satisfy the ITER requirement. As the frequency of 170 GHz is expected for the maximum toroidal field of 5.3 T at the plasma center of ITER, it is useful to estimate a frequency tunability of the gyrotron for the operation at lower toroidal filed. A simulation indicates that a similar performance is obtained at ~137 GHz oscillation at $TE_{27,6}$ mode with the 170 $GHz/TE_{31,8}$ mode oscillation. Both modes penetrate the diamond window of 1.853 mm in thickness. The triode magnetron injection gun (MIG) generates the rotational electron beam of low velocity divergence for both operation parameters. As for a fast frequency control, which will be useful for profile control in the fusion plasma, a He-free magnet with an additional super conducting sweeping coil was developed. A diameter of a room temperature bore is 240 mm, and the 7 T at the center. Using a commercially available standard DC power supplies, the magnetic field sweeping was demonstrated with a speed of 0.4 T/10 sec at 7 T.
Starting Page	1
Ending Page	1
File Size	76568
Page Count	1
File Format	PDF
ISBN	9781424419296
ISSN	07309244
DOI	10.1109/PLASMA.2008.4590753
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2008-06-15
Publisher Place	Germany
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Gyrotrons Oscillators Plasmas Toroidal magnetic fields Frequency estimation Inductors Cyclotrons
Content Type	Text
Resource Type	Article
Subject	Atomic and Molecular Physics, and Optics Condensed Matter Physics Electrical and Electronic Engineering

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in