Solenoid-free Plasma Startup in NSTX using Coaxial Helicity Injection

Technical Report · Mon Jan 03 04:00:00 EST 2005

DOI:https://doi.org/10.2172/836595· OSTI ID:836595

Raman, Roger ^[1]; Jarboe, Thomas R; Bell, Michael G; Mueller, Dennis; Nelson, Brian A; LeBlanc, Benoit; Bush, Charles; Nagata, Masayoshi; Biewer, Ted

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1. Princeton Plasma Physics Laboratory

The favorable properties of the Spherical Torus (ST) arise from its very small aspect ratio. However, small aspect ratio devices have very restricted space for a substantial central solenoid. Thus methods for initiating the plasma current without relying on induction from a central solenoid are essential for the viability of the ST concept. Coaxial Helicity Injection (CHI) is a promising candidate for solenoid-free plasma startup in a ST. Recent experiments on the HIT-II ST at the University of Washington, have demonstrated the capability of a new method, referred to as transient CHI, to produce a high quality, closed-flux equilibrium that has then been coupled to induction, with a reduced requirement for transformer flux [R. Raman, T.R. Jarboe, B.A. Nelson, et al., Phys. Rev. Lett. 90 (February 2003) 075005-1]. An initial test of this method on the National Spherical Torus Experiment (NSTX) has produced about 140 kA of toroidal current. Modifications are now underway to improve capability for transient CHI in NSTX.

• Research Organization: Princeton Plasma Physics Lab., Princeton, NJ (US)
• Sponsoring Organization: USDOE Office of Science (SC) (US)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 836595
• Report Number(s): PPPL-4042
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASPECT RATIO
CURRENT DRIVE
ELECTRIC CURRENTS
HELICITY
INDUCTION
MAGNETIC RECONNECTION
MODIFICATIONS
PLASMA
SOLENOIDS
SPHERICAL TORUS
TRANSFORMERS
TRANSIENTS
VIABILITY