The X-point scrape-off plasma in jet with L- and H-modes

P. J. Harbour; D. D.R. Summers; S. Clement; J. P. Coad; L. De Kock; J. Ehrenberg; K. Erents; N. Gottardi; A. Hubbard; M. Keilhacker; P. D. Morgan; J. A. Snipes; M. F. Stamp; J. A. Tagle; A. Tanga; R. Behrisch; Wen Min Wang

doi:10.1016/0022-3115(89)90276-6

The X-point scrape-off plasma in jet with L- and H-modes

P. J. Harbour
, D. D.R. Summers
, S. Clement
, J. P. Coad
, L. De Kock
, J. Ehrenberg
, K. Erents
, N. Gottardi
, A. Hubbard
, M. Keilhacker
, P. D. Morgan
, J. A. Snipes
, M. F. Stamp
, J. A. Tagle
, A. Tanga
, R. Behrisch
, Wen Min Wang

Research output: Contribution to journal › Article › peer-review

61 Scopus citations

Abstract

The JET scrape-off plasma during X-point discharges with L- and H-modes is described. There is a flow of current in the scrape-off layer which can influence equilibrium, transport, heating and impurity generation in the scrape-off layer. A local measurement of D_⊥ is obtained in the divertor region. The saturated flux of ions flowing parallel to the magnetic field, I_SAT is ∼10 A/cm² at the divertor separatrix in ohmic discharges. In L-mode with NBI it increases by a factor ≤ 2, depending on injected power level (P_NBI < 8 MW) and decreases with H-mode. The e-folding decay length, λ _{I_SAT}, is the same in ohmic and L-mode but decreases with H-mode. The electron temperatures at the divertor target are ~ 30 eV (OH) and ~ 50-60 eV (H-mode). Measurements of T_e during L-mode are not reported because of the high level of fluctuations. An enhancement in the erosion of carbon due to ion-stimulated desorption at the divertor target is discussed. Flow reversal in the scrape-off layer is demonstrated.

Original language	English (US)
Pages (from-to)	236-244
Number of pages	9
Journal	Journal of Nuclear Materials
Volume	162-164
Issue number	C
DOIs	https://doi.org/10.1016/0022-3115(89)90276-6
State	Published - Apr 1 1989
Externally published	Yes

All Science Journal Classification (ASJC) codes

Nuclear and High Energy Physics
General Materials Science
Nuclear Energy and Engineering

Keywords

flow reversal
ion-induced desorption
JET
L- and H-modes
probes
scrape-off layer
X-Point

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10.1016/0022-3115(89)90276-6

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Harbour, P. J., Summers, D. D. R., Clement, S., Coad, J. P., De Kock, L., Ehrenberg, J., Erents, K., Gottardi, N., Hubbard, A., Keilhacker, M., Morgan, P. D., Snipes, J. A., Stamp, M. F., Tagle, J. A., Tanga, A., Behrisch, R., & Wang, W. M. (1989). The X-point scrape-off plasma in jet with L- and H-modes. Journal of Nuclear Materials, 162-164(C), 236-244. https://doi.org/10.1016/0022-3115(89)90276-6

@article{7df0ccecd6e24a02828c85523ed71b71,

title = "The X-point scrape-off plasma in jet with L- and H-modes",

abstract = "The JET scrape-off plasma during X-point discharges with L- and H-modes is described. There is a flow of current in the scrape-off layer which can influence equilibrium, transport, heating and impurity generation in the scrape-off layer. A local measurement of D⊥ is obtained in the divertor region. The saturated flux of ions flowing parallel to the magnetic field, ISAT is ∼10 A/cm2 at the divertor separatrix in ohmic discharges. In L-mode with NBI it increases by a factor ≤ 2, depending on injected power level (PNBI < 8 MW) and decreases with H-mode. The e-folding decay length, λ ISAT, is the same in ohmic and L-mode but decreases with H-mode. The electron temperatures at the divertor target are \textasciitilde{} 30 eV (OH) and \textasciitilde{} 50-60 eV (H-mode). Measurements of Te during L-mode are not reported because of the high level of fluctuations. An enhancement in the erosion of carbon due to ion-stimulated desorption at the divertor target is discussed. Flow reversal in the scrape-off layer is demonstrated.",

keywords = "flow reversal, ion-induced desorption, JET, L- and H-modes, probes, scrape-off layer, X-Point",

author = "Harbour, \{P. J.\} and Summers, \{D. D.R.\} and S. Clement and Coad, \{J. P.\} and \{De Kock\}, L. and J. Ehrenberg and K. Erents and N. Gottardi and A. Hubbard and M. Keilhacker and Morgan, \{P. D.\} and Snipes, \{J. A.\} and Stamp, \{M. F.\} and Tagle, \{J. A.\} and A. Tanga and R. Behrisch and Wang, \{Wen Min\}",

year = "1989",

month = apr,

day = "1",

doi = "10.1016/0022-3115(89)90276-6",

language = "English (US)",

volume = "162-164",

pages = "236--244",

journal = "Journal of Nuclear Materials",

issn = "0022-3115",

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}

Harbour, PJ, Summers, DDR, Clement, S, Coad, JP, De Kock, L, Ehrenberg, J, Erents, K, Gottardi, N, Hubbard, A, Keilhacker, M, Morgan, PD, Snipes, JA, Stamp, MF, Tagle, JA, Tanga, A, Behrisch, R & Wang, WM 1989, 'The X-point scrape-off plasma in jet with L- and H-modes', Journal of Nuclear Materials, vol. 162-164, no. C, pp. 236-244. https://doi.org/10.1016/0022-3115(89)90276-6

TY - JOUR

T1 - The X-point scrape-off plasma in jet with L- and H-modes

AU - Harbour, P. J.

AU - Summers, D. D.R.

AU - Clement, S.

AU - Coad, J. P.

AU - De Kock, L.

AU - Ehrenberg, J.

AU - Erents, K.

AU - Gottardi, N.

AU - Hubbard, A.

AU - Keilhacker, M.

AU - Morgan, P. D.

AU - Snipes, J. A.

AU - Stamp, M. F.

AU - Tagle, J. A.

AU - Tanga, A.

AU - Behrisch, R.

AU - Wang, Wen Min

PY - 1989/4/1

Y1 - 1989/4/1

N2 - The JET scrape-off plasma during X-point discharges with L- and H-modes is described. There is a flow of current in the scrape-off layer which can influence equilibrium, transport, heating and impurity generation in the scrape-off layer. A local measurement of D⊥ is obtained in the divertor region. The saturated flux of ions flowing parallel to the magnetic field, ISAT is ∼10 A/cm2 at the divertor separatrix in ohmic discharges. In L-mode with NBI it increases by a factor ≤ 2, depending on injected power level (PNBI < 8 MW) and decreases with H-mode. The e-folding decay length, λ ISAT, is the same in ohmic and L-mode but decreases with H-mode. The electron temperatures at the divertor target are ~ 30 eV (OH) and ~ 50-60 eV (H-mode). Measurements of Te during L-mode are not reported because of the high level of fluctuations. An enhancement in the erosion of carbon due to ion-stimulated desorption at the divertor target is discussed. Flow reversal in the scrape-off layer is demonstrated.

AB - The JET scrape-off plasma during X-point discharges with L- and H-modes is described. There is a flow of current in the scrape-off layer which can influence equilibrium, transport, heating and impurity generation in the scrape-off layer. A local measurement of D⊥ is obtained in the divertor region. The saturated flux of ions flowing parallel to the magnetic field, ISAT is ∼10 A/cm2 at the divertor separatrix in ohmic discharges. In L-mode with NBI it increases by a factor ≤ 2, depending on injected power level (PNBI < 8 MW) and decreases with H-mode. The e-folding decay length, λ ISAT, is the same in ohmic and L-mode but decreases with H-mode. The electron temperatures at the divertor target are ~ 30 eV (OH) and ~ 50-60 eV (H-mode). Measurements of Te during L-mode are not reported because of the high level of fluctuations. An enhancement in the erosion of carbon due to ion-stimulated desorption at the divertor target is discussed. Flow reversal in the scrape-off layer is demonstrated.

KW - flow reversal

KW - ion-induced desorption

KW - JET

KW - L- and H-modes

KW - probes

KW - scrape-off layer

KW - X-Point

UR - https://www.scopus.com/pages/publications/0039158924

UR - https://www.scopus.com/pages/publications/0039158924#tab=citedBy

U2 - 10.1016/0022-3115(89)90276-6

DO - 10.1016/0022-3115(89)90276-6

M3 - Article

AN - SCOPUS:0039158924

SN - 0022-3115

VL - 162-164

SP - 236

EP - 244

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

IS - C

ER -

The X-point scrape-off plasma in jet with L- and H-modes

Abstract

All Science Journal Classification (ASJC) codes

Keywords

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