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Title: Grill design for 1000 second lower hybrid current drive system for SST1 tokamak

Abstract

In this paper we present detail design considerations for the grill structure designed to be used as the launching structure for the Lower Hybrid Current Drive (LHCD) system for 1000 second operation in Steadystate Superconducting Tokamak (SST1). The grill will comprise of 64 active subwaveguides having dimensions of 76mmx7mm, arranged in two rows with two dummy subwaveguides, one each on either side of the row. The grill is designed to radiate a power spectrum of parallel refractive index, centered at 2.25, with 90 deg. phasing. The power flux in each subwaveguide is {approx}3 kW/cm{sup 2} for a rf power of 1 MW coupled to the plasma. To protect the grill from conducted and radiated heat loads, there will be a tile assembly around the perimeter of the grill structure. High heat loads on the protection tiles ({approx}52 W/cm{sup 2}) and the grill (6.8 kW, both radiated and resistive loss), demand careful and constant cooling. Thermal, electromagnetic and mechanical stresses have been analyzed for the grill and the tile assembly using ANSYS software. Analysis for the grill shows that the maximum operating temperature of the grill would be 75 deg. C, giving rise to a thermal stress of 18 MPa. Mostmore » critical tiles would be the corner tiles with an operating temperature of 412 deg. C and a thermal stress of 35 MPa, which is 83% of the yield stress of the graphite material. Maximum force developed on the grill due to plasma disruption has been estimated to be about 13 kN. Zr-Cr copper with adequate strength will be used to fabricate the grill structure. Wire-cut technique will be used to fabricate the grill, having an internal surface finish of 1.5 {mu}m.« less

Authors:
; ; ;  [1]
  1. Institute for Plasma Research, Bhat, Gandhinagar-382 424 (India)
Publication Date:
OSTI Identifier:
21210514
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 485; Journal Issue: 1; Conference: 13. topical conference on radio frequency power in plasmas, Annapolis, MD (United States), 12-14 Apr 1999; Other Information: DOI: 10.1063/1.59713; (c) 1999 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; A CODES; COMPUTERIZED SIMULATION; COPPER; DESIGN; ELECTRIC CURRENTS; GRAPHITE; HEATING LOAD; KLYSTRONS; LOWER HYBRID CURRENT DRIVE; OPERATION; PLASMA; PLASMA DISRUPTION; PLASMA SIMULATION; REFRACTIVE INDEX; RF SYSTEMS; SUPERCONDUCTING MAGNETS; THERMAL STRESSES; TOKAMAK DEVICES

Citation Formats

Bora, D., Sharma, P. K., Rao, S. Laxmikanth, and Samanta and RF Group, K. K. Grill design for 1000 second lower hybrid current drive system for SST1 tokamak. United States: N. p., 1999. Web. doi:10.1063/1.59713.
Bora, D., Sharma, P. K., Rao, S. Laxmikanth, & Samanta and RF Group, K. K. Grill design for 1000 second lower hybrid current drive system for SST1 tokamak. United States. doi:10.1063/1.59713.
Bora, D., Sharma, P. K., Rao, S. Laxmikanth, and Samanta and RF Group, K. K. Mon . "Grill design for 1000 second lower hybrid current drive system for SST1 tokamak". United States. doi:10.1063/1.59713.
@article{osti_21210514,
title = {Grill design for 1000 second lower hybrid current drive system for SST1 tokamak},
author = {Bora, D. and Sharma, P. K. and Rao, S. Laxmikanth and Samanta and RF Group, K. K.},
abstractNote = {In this paper we present detail design considerations for the grill structure designed to be used as the launching structure for the Lower Hybrid Current Drive (LHCD) system for 1000 second operation in Steadystate Superconducting Tokamak (SST1). The grill will comprise of 64 active subwaveguides having dimensions of 76mmx7mm, arranged in two rows with two dummy subwaveguides, one each on either side of the row. The grill is designed to radiate a power spectrum of parallel refractive index, centered at 2.25, with 90 deg. phasing. The power flux in each subwaveguide is {approx}3 kW/cm{sup 2} for a rf power of 1 MW coupled to the plasma. To protect the grill from conducted and radiated heat loads, there will be a tile assembly around the perimeter of the grill structure. High heat loads on the protection tiles ({approx}52 W/cm{sup 2}) and the grill (6.8 kW, both radiated and resistive loss), demand careful and constant cooling. Thermal, electromagnetic and mechanical stresses have been analyzed for the grill and the tile assembly using ANSYS software. Analysis for the grill shows that the maximum operating temperature of the grill would be 75 deg. C, giving rise to a thermal stress of 18 MPa. Most critical tiles would be the corner tiles with an operating temperature of 412 deg. C and a thermal stress of 35 MPa, which is 83% of the yield stress of the graphite material. Maximum force developed on the grill due to plasma disruption has been estimated to be about 13 kN. Zr-Cr copper with adequate strength will be used to fabricate the grill structure. Wire-cut technique will be used to fabricate the grill, having an internal surface finish of 1.5 {mu}m.},
doi = {10.1063/1.59713},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 485,
place = {United States},
year = {1999},
month = {9}
}