1. The effects of chromium and titanium gettering on the operation of the Advanced Toroidal Facility
- Author
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I.E. Simpkins, T.C. Jernigan, A.C. England, T.S. Bigelow, P.K. Mioduszewski, David A Rasmussen, W.R. Wing, M. Murakami, E.C. Crume, G. L. Bell, R. A. Langley, John B Wilgen, R.C. Isler, J.C. Glowienka, and L.D. Horton
- Subjects
Nuclear and High Energy Physics ,Electron density ,Glow discharge ,Tokamak ,Chemistry ,Cyclotron ,Analytical chemistry ,chemistry.chemical_element ,Plasma ,Effective radiated power ,Neutral beam injection ,law.invention ,Nuclear Energy and Engineering ,law ,General Materials Science ,Atomic physics ,Titanium - Abstract
Plasmas in the Advanced Toroidal Facility (ATF), an l = 2 torsatron with 12 field periods, are produced by 200–400 kW of electron cyclotron heating (ECH) and up to 1.5 MW of neutral-beam injection (NBI). The characteristics of the plasmas are sensitive to the type of wall conditioning employed. A progression of techniques, beginning with glow discharge cleaning and baking and evolving to gettering with chromium and titanium, has significantly reduced the low-Z impurity content, lowered the fraction of radiated power, and permitted improved control over the electron density. As a result, plasma-parameters and machine performance have been enhanced significantly. The maximum values achieved for stored energy, line-averaged density, and confinement times are 28 kJ, 1.2 × 1020m−3, and 25 ms. These parameters are comparable to those obtained in the ISX-B tokamak. In addition, with titanium gettering, quasisteady operation for 200 ms of neutral beam injection has been obtained without the collapses that characterized earlier periods of operation.
- Published
- 1990
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