Tritium transport studies on TFTR

Conference · Wed Jun 01 04:00:00 EDT 1994

OSTI ID:10168374

Johnson, L. C. ^[1]; Efthimion, P. C. ^[1]; Strachan, J. D. ^[1]; Synakowski, E. ^[1]; Zarnstorff, M. ^[1]; McCune, D. ^[1]; Roquemore, A. L. ^[1]; Loughlin, M. ^[2]; Barnes, C. W. ^[3]

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1. Princeton Univ., NJ (United States). Plasma Physics Lab.
2. JET Joint Undertaking, Abingdon (United Kingdom)
3. Los Alamos National Lab., NM (United States)

This paper reports the first results of tritium transport studies on TFTR. Gas puffs of either pure tritium or trace-tritium (2% T₂ and 98% D₂) were injected into low-recycling deuterium neutral beam heated plasmas, referred to as supershots, and the temporal and spatial evolution of the resulting 14.1 MeV t(d,n) α neutron emission was measured. Because of the high reactivity of tritium with energetic deuterons, small gas puffs are sufficient to provide a significant increase in neutron emissivity without seriously perturbing other plasma parameters. By analyzing the time evolution of the D-T neutron emission profile after a gas puff, the local tritium density may be inferred. In order to compare with earlier work on TFTR, we chose plasma conditions to closely match those of the supershots studied. A total of ~14 MW of deuterium neutral beams, with a maximum energy of ~100 keV, were injected both co-tangential and counter-tangential with respect to plasma current, to minimize plasma rotation. The plasma had a toroidal field strength of 4.8 T, a major radius of 2.45 m, a minor radius of 0.8 m, and a plasma current of 1.15 MA. The central electron and ion temperatures were 7.5 keV and 25 keV, respectively, and the central electron density was 5 x 10¹⁹ m^-3. Global energy confinement time was 0.16 s, which is about three times the L-mode scaling value. Neutral beam injection was from 3 to 4 s, and the tritium gas puff was applied at 3.5 s.

• Research Organization: Princeton Univ., NJ (United States). Plasma Physics Lab.
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03073; W-7405-ENG-36
• OSTI ID: 10168374
• Report Number(s): PPPL-CFP--3101; LA-UR--94-2430; CONF-940635--2; ON: DE94015563
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700330
CHARGED-PARTICLE TRANSPORT
NEUTRAL ATOM BEAM INJECTION
PLASMA KINETICS, TRANSPORT, AND IMPURITIES
TFTR TOKAMAK
TRITIUM