Jarboe TR, Hamp WT, Marklin GJ, Nelson BA, O'neill RG, Redd AJ, Sieck PE, Smith RJ, Wrobel JS. Spheromak formation by steady inductive helicity injection.
PHYSICAL REVIEW LETTERS 2006;
97:115003. [PMID:
17025894 DOI:
10.1103/physrevlett.97.115003]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Indexed: 05/12/2023]
Abstract
A spheromak is formed for the first time using a new steady state inductive helicity injection method. Using two inductive injectors with odd symmetry and oscillating at 5.8 kHz, a steady state spheromak with even symmetry is formed and sustained through nonlinear relaxation. A spheromak with about 13 kA of toroidal current is formed and sustained using about 3 MW of power. This is a much lower power threshold for spheromak production than required for electrode-based helicity injection. Internal magnetic probe data, including oscillations driven by the injectors, agree with the plasma being in the Taylor state. The agreement is remarkable considering the only fitting parameter is the amplitude of the spheromak component of the state.
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