Studies of high-δ (baffled) and low-δ (open) pumped divertor operation on DIII-D

S. L. Allen; M. E. Fenstermacher; C. M. Greenfield; A. W. Hyatt; R. Maingi; G. D. Porter; M. R. Wade; A. S. Bozek; R. Ellis; D. N. Hill; M. A. Hollerbach; C. J. Lasnier; A. W. Leonard; M. A. Mahdavi; D. G. Nilson; T. W. Petrie; M. J. Schaffer; J. P. Smith; R. D. Stambaugh; D. M. Thomas; J. G. Watkins; W. P. West; D. G. Whyte; R. D. Wood

doi:10.1016/S0022-3115(98)00523-6

Studies of high-δ (baffled) and low-δ (open) pumped divertor operation on DIII-D

S. L. Allen
, M. E. Fenstermacher
, C. M. Greenfield
, A. W. Hyatt
, R. Maingi
, G. D. Porter
, M. R. Wade
, A. S. Bozek
, R. Ellis
, D. N. Hill
, M. A. Hollerbach
, C. J. Lasnier
, A. W. Leonard
, M. A. Mahdavi
, D. G. Nilson
, T. W. Petrie
, M. J. Schaffer
, J. P. Smith
, R. D. Stambaugh
, D. M. Thomas

J. G. Watkins, W. P. West, D. G. Whyte, R. D. Wood

Fusion and Fission Energy and Science Di

Research output: Contribution to journal › Conference article › peer-review

24 Scopus citations

Abstract

We report new experimental results with the Radiative Divertor Project-outer baffle (RDP-OB) and cryopump in both upper single-null (USN) and double-null (DN) ELMing H-mode discharges. The baffled divertor reduced the core ionization (approximately 2-2.5×), in reasonable agreement with predictions from UEDGE/DEGAS modeling (approximately 3.75×). The upper cryopump achieved density control of n_e/n_gw to approximately 0.22 (line density/Greenwald density) with Z_eff to approximately 2 in high-δ plasmas. The measured exhaust is comparable to the lower pump, except at lower core electron densities (n_e<5×10¹⁹ m^-3). Efficient impurity exhaust was obtained with deuterium SOL flow. Preliminary experiments with DN operation has shown that the particle exhaust to the upper pump depends on the up/down magnetic balance. Preliminary experiments indicate that the DN exhaust is roughly 40-50% of the USN exhaust at n_e to approximately 4×10¹⁹ m^-3.

Original language	English
Pages (from-to)	168-174
Number of pages	7
Journal	Journal of Nuclear Materials
Volume	266
DOIs	https://doi.org/10.1016/S0022-3115(98)00523-6
State	Published - Mar 2 1999

Funding

This work was made possible by a large number technical personnel that designed and installed the RDP-OB hardware. The DIII-D operations team ensured the divertor and tokamak hardware were ready for experiments, and that the plasma control system could achieve the desired shapes. The AT + D Task Force planned, executed and analyzed the data from the experiments. Work supported by US Department of Energy under Contracts DE-AC03-89ER51114, DE-AC05-96OR22464, W-7405-ENG-48, DE-AC04-94AL85000, and Grant DE-FG03-95ER54294.

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Allen, S. L., Fenstermacher, M. E., Greenfield, C. M., Hyatt, A. W., Maingi, R., Porter, G. D., Wade, M. R., Bozek, A. S., Ellis, R., Hill, D. N., Hollerbach, M. A., Lasnier, C. J., Leonard, A. W., Mahdavi, M. A., Nilson, D. G., Petrie, T. W., Schaffer, M. J., Smith, J. P., Stambaugh, R. D., ... Wood, R. D. (1999). Studies of high-δ (baffled) and low-δ (open) pumped divertor operation on DIII-D. Journal of Nuclear Materials, 266, 168-174. https://doi.org/10.1016/S0022-3115(98)00523-6

@article{722cc691fc754a0a805452aacbe84907,

title = "Studies of high-δ (baffled) and low-δ (open) pumped divertor operation on DIII-D",

abstract = "We report new experimental results with the Radiative Divertor Project-outer baffle (RDP-OB) and cryopump in both upper single-null (USN) and double-null (DN) ELMing H-mode discharges. The baffled divertor reduced the core ionization (approximately 2-2.5×), in reasonable agreement with predictions from UEDGE/DEGAS modeling (approximately 3.75×). The upper cryopump achieved density control of ne/ngw to approximately 0.22 (line density/Greenwald density) with Zeff to approximately 2 in high-δ plasmas. The measured exhaust is comparable to the lower pump, except at lower core electron densities (ne<5×1019 m-3). Efficient impurity exhaust was obtained with deuterium SOL flow. Preliminary experiments with DN operation has shown that the particle exhaust to the upper pump depends on the up/down magnetic balance. Preliminary experiments indicate that the DN exhaust is roughly 40-50\% of the USN exhaust at ne to approximately 4×1019 m-3.",

author = "Allen, \{S. L.\} and Fenstermacher, \{M. E.\} and Greenfield, \{C. M.\} and Hyatt, \{A. W.\} and R. Maingi and Porter, \{G. D.\} and Wade, \{M. R.\} and Bozek, \{A. S.\} and R. Ellis and Hill, \{D. N.\} and Hollerbach, \{M. A.\} and Lasnier, \{C. J.\} and Leonard, \{A. W.\} and Mahdavi, \{M. A.\} and Nilson, \{D. G.\} and Petrie, \{T. W.\} and Schaffer, \{M. J.\} and Smith, \{J. P.\} and Stambaugh, \{R. D.\} and Thomas, \{D. M.\} and Watkins, \{J. G.\} and West, \{W. P.\} and Whyte, \{D. G.\} and Wood, \{R. D.\}",

year = "1999",

month = mar,

day = "2",

doi = "10.1016/S0022-3115(98)00523-6",

language = "English",

volume = "266",

pages = "168--174",

journal = "Journal of Nuclear Materials",

issn = "0022-3115",

publisher = "Elsevier",

}

Allen, SL, Fenstermacher, ME, Greenfield, CM, Hyatt, AW, Maingi, R, Porter, GD, Wade, MR, Bozek, AS, Ellis, R, Hill, DN, Hollerbach, MA, Lasnier, CJ, Leonard, AW, Mahdavi, MA, Nilson, DG, Petrie, TW, Schaffer, MJ, Smith, JP, Stambaugh, RD, Thomas, DM, Watkins, JG, West, WP, Whyte, DG & Wood, RD 1999, 'Studies of high-δ (baffled) and low-δ (open) pumped divertor operation on DIII-D', Journal of Nuclear Materials, vol. 266, pp. 168-174. https://doi.org/10.1016/S0022-3115(98)00523-6

TY - JOUR

T1 - Studies of high-δ (baffled) and low-δ (open) pumped divertor operation on DIII-D

AU - Allen, S. L.

AU - Fenstermacher, M. E.

AU - Greenfield, C. M.

AU - Hyatt, A. W.

AU - Maingi, R.

AU - Porter, G. D.

AU - Wade, M. R.

AU - Bozek, A. S.

AU - Ellis, R.

AU - Hill, D. N.

AU - Hollerbach, M. A.

AU - Lasnier, C. J.

AU - Leonard, A. W.

AU - Mahdavi, M. A.

AU - Nilson, D. G.

AU - Petrie, T. W.

AU - Schaffer, M. J.

AU - Smith, J. P.

AU - Stambaugh, R. D.

AU - Thomas, D. M.

AU - Watkins, J. G.

AU - West, W. P.

AU - Whyte, D. G.

AU - Wood, R. D.

PY - 1999/3/2

Y1 - 1999/3/2

N2 - We report new experimental results with the Radiative Divertor Project-outer baffle (RDP-OB) and cryopump in both upper single-null (USN) and double-null (DN) ELMing H-mode discharges. The baffled divertor reduced the core ionization (approximately 2-2.5×), in reasonable agreement with predictions from UEDGE/DEGAS modeling (approximately 3.75×). The upper cryopump achieved density control of ne/ngw to approximately 0.22 (line density/Greenwald density) with Zeff to approximately 2 in high-δ plasmas. The measured exhaust is comparable to the lower pump, except at lower core electron densities (ne<5×1019 m-3). Efficient impurity exhaust was obtained with deuterium SOL flow. Preliminary experiments with DN operation has shown that the particle exhaust to the upper pump depends on the up/down magnetic balance. Preliminary experiments indicate that the DN exhaust is roughly 40-50% of the USN exhaust at ne to approximately 4×1019 m-3.

AB - We report new experimental results with the Radiative Divertor Project-outer baffle (RDP-OB) and cryopump in both upper single-null (USN) and double-null (DN) ELMing H-mode discharges. The baffled divertor reduced the core ionization (approximately 2-2.5×), in reasonable agreement with predictions from UEDGE/DEGAS modeling (approximately 3.75×). The upper cryopump achieved density control of ne/ngw to approximately 0.22 (line density/Greenwald density) with Zeff to approximately 2 in high-δ plasmas. The measured exhaust is comparable to the lower pump, except at lower core electron densities (ne<5×1019 m-3). Efficient impurity exhaust was obtained with deuterium SOL flow. Preliminary experiments with DN operation has shown that the particle exhaust to the upper pump depends on the up/down magnetic balance. Preliminary experiments indicate that the DN exhaust is roughly 40-50% of the USN exhaust at ne to approximately 4×1019 m-3.

UR - https://www.scopus.com/pages/publications/0032627067

U2 - 10.1016/S0022-3115(98)00523-6

DO - 10.1016/S0022-3115(98)00523-6

M3 - Conference article

AN - SCOPUS:0032627067

SN - 0022-3115

VL - 266

SP - 168

EP - 174

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

ER -

Studies of high-δ (baffled) and low-δ (open) pumped divertor operation on DIII-D

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