Return To: Session FT/1 - Technology Developments
Prev Page: (FT/1-3Rb) Design and Fabrication of Form-insulated Cryogenic Target
Next Page: (FT/1-5) The Spherical Tokamak Power Plant

(FT/1-4) Design Innovations of the Next-Step Spherical Torus Experiment and Spherical Torus Development Path

M.O. Ono¹⁾, M. Peng²⁾, C. Kessel¹⁾, C. Neumeyer¹⁾, J. Schmidt¹⁾, J. Chrzanowski¹⁾, D. Darrow¹⁾, L. Grisham¹⁾, P. Heitzenroeder¹⁾, T. Jarboe³⁾, C. Jun¹⁾, S. Kaye¹⁾, J. Menard¹⁾, R. Raman³⁾, T. Stevenson¹⁾, M. Viola¹⁾, J. Wilson¹⁾, R. Woolley¹⁾, I. Zatz^1)
 
1) Princeton University, Plasma Physics Laboratory, Princeton, USA
²⁾ Oak Ridge National Laboratory, Oak Ridge, TN, USA,
³⁾ University of Washington, Seattle, WA, USA

Abstract.  An innovative flexible design of next-step spherical torus (NSST) device with IpA = 8 - 16 MA is presented. The NSST magnets are liquid nitrogen cooled to allow long pulse non-inductive research (t-pulse = 50 sec at 6 MA with B-TF = 1.1 T, Q = 0.25 at HH=1.4), as well as high performance alpha-particle physics research (t-pulse = 5 sec at 10 MA with B-TF = 2.7 T, Q = 2 at HH=1.4). An innovative two-part OH coil concept is designed to provide sufficient inductive capability. The center-stack contains inboard PF coils to allow strong plasma shaping needed for Advanced ST operations. The TF outer legs are shaped to eliminate the needs for complex sliding joints. A removable center stack is designed to facilitate maintenance, allow for the possibility of future upgrades, and simplify remote maintenance. The present NSST design utilizes the TFTR site, which satisfies the NSST electrical power and the long pulse auxiliary heating and current drive power (30 MW of NBI and 10 MW of ICRF) requirements. An assessment of how the next-generation ST devices such as NSST and VNS can contribute toward fusion energy development will be also presented.

Read the full paper in PDF format.