Local transport measurements during auxiliary heating in TFTR

S. D. Scott, C. W. Barnes, L. R. Grisham, G. W. Hammett, W. W. Heidbrink, D. W. Johnson, Y. Kusama, M. C. Zarnstorff, S. J. Zweben, M. G. Bell, M. Bitter, R. Boivin, R. Budny, C. E. Bush, A. Cavallo, C. Z. Cheng

Research output: Chapter in Book/Report/Conference proceedingConference contribution

13 Citations (Scopus)

Abstract

Local heat and momentum transport is analyzed in beam-heated steady-state TFTR plasmas using measured profiles for temperature and rotation speed over a wide range of plasma conditions. As heating power is increased in high-recycling 'L-mode' plasmas, the thermal diffusivities χi(r) and χe(r) are found to increase strongly with temperature throughout the plasma confinement zone. Both chii and chie decrease with increasing plasma current in steady state L-mode plasmas. Dedicated major-radius and aspect ratio scaling experiments show that the global confinement time τE has a strong dependence on major radius and a weak dependence on minor radius in L-mode plasmas, τE ∝ Rapproximately 1.6 aapproximately 0. Kadomtsev dimensionless scaling of the ohmic τE obtained in Alcator C and PLT to TFTR at constant n̄e/BT1.6, qcyl, and a/R underpredicts τE by about a factor of two, possibly due to variations in Ln(e)/a. Ion heat and momentum transport in low-recycling TFTR 'supershot' plasmas shows an inverse dependence on temperature. Several independent measurements of radial-particle transport indicate diffusivities of order ≲0.1 m2/s for energetic ions (approximately 30 keV → MeV), an order of magnitude less than the observed thermal transport rates.

Original languageEnglish
Title of host publicationProc 13 Int Conf Plasma Phys Controlled Nucl Fusion Res
PublisherPubl by IAEA
Pages235-259
Number of pages25
ISBN (Print)9201300913
Publication statusPublished - 1991 Jan 1

Publication series

NameProc 13 Int Conf Plasma Phys Controlled Nucl Fusion Res

All Science Journal Classification (ASJC) codes

  • Engineering(all)

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