Radiation asymmetries during disruptions on DIII-D caused by massive gas injection

被引：24

作者：

Commaux, N. ^{[1
]}

Baylor, L. R. ^{[1
]}

Jernigan, T. C. ^{[1
]}

Hollmann, E. M. ^{[2
]}

Humphreys, D. A. ^{[3
]}

Wesley, J. C. ^{[3
]}

Izzo, V. A. ^{[2
]}

Eidietis, N. W. ^{[3
]}

Lasnier, C. J. ^{[4
]}

Moyer, R. A. ^{[2
]}

Parks, P. B. ^{[3
]}

Foust, C. R. ^{[1
]}

Combs, S. ^{[1
]}

Meitner, S. J. ^{[1
]}

机构：

[1] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA

[2] Univ Calif San Diego, San Diego, CA 92103 USA

[3] Gen Atom Co, San Diego, CA USA

[4] Lawrence Livermore Natl Lab, Livermore, CA USA

来源：

PHYSICS OF PLASMAS | 2014年 / 21卷 / 10期

关键词：

MITIGATION;

D O I：

10.1063/1.4896721

中图分类号：

O35 [流体力学]; O53 [等离子体物理学];

学科分类号：

070204 ; 080103 ; 080704 ;

摘要：

One of the major challenges that the ITER tokamak will have to face during its operations are disruptions. During the last few years, it has been proven that the global consequences of a disruption can be mitigated by the injection of large quantities of impurities. But one aspect that has been difficult to study was the possibility of local effects inside the torus during such injection that could damage a portion of the device despite the global heat losses and generated currents remaining below design parameter. 3D MHD simulations show that there is a potential for large toroidal asymmetries of the radiated power during impurity injection due to the interaction between the particle injection plume and a large n = 1 mode. Another aspect of 3D effects is the potential occurrence of Vertical Displacement Events (VDE), which could induce large poloidal heat load asymmetries. This potential deleterious effect of 3D phenomena has been studied on the DIII-D tokamak, thanks to the implementation of a multi-location massive gas injection (MGI) system as well as new diagnostic capabilities. This study showed the existence of a correlation between the location of the n = 1 mode and the local heat load on the plasma facing components but shows also that this effect is much smaller than anticipated (peaking factor of similar to 1.1 vs 3-4 according to the simulations). There seems to be no observable heat load on the first wall of DIII-D at the location of the impurity injection port as well as no significant radiation asymmetries whether one or 2 valves are fired. This study enabled the first attempt of mitigation of a VDE using impurity injection at different poloidal locations. The results showed a more favorable heat deposition when the VDE is mitigated early (right at the onset) by impurity injection. No significant improvement of the heat load mitigation efficiency has been observed for late particle injection whether the injection is done "in the way" of the VDE (upward VDE mitigated by injection from the upper part of the vessel vs the lower part) or not. (C) 2014 AIP Publishing LLC.

引用

页数：8

共 17 条

[1] Demonstration of rapid shutdown using large shattered deuterium pellet injection in DIII-D [J].

Commaux, N. ;

Baylor, L. R. ;

Jernigan, T. C. ;

Hollmann, E. M. ;

Parks, P. B. ;

Humphreys, D. A. ;

Wesley, J. C. ;

Yu, J. H. .

NUCLEAR FUSION, 2010, 50 (11)

[2] Gas jet disruption mitigation studies on Alcator C-Mod and DIII-D [J].

Granetz, R. S. ;

Hollmann, E. M. ;

Whyte, D. G. ;

Izzo, V. A. ;

Antar, G. Y. ;

Bader, A. ;

Bakhtiari, M. ;

Biewer, T. ;

Boedo, J. A. ;

Evans, T. E. ;

Hutchinson, I. H. ;

Jernigan, T. C. ;

Gray, D. S. ;

Groth, M. ;

Humphreys, D. A. ;

Lasnier, C. J. ;

Moyer, R. A. ;

Parks, P. B. ;

Reinke, M. L. ;

Rudakov, D. L. ;

Strait, E. J. ;

Terry, J. L. ;

Wesley, J. ;

West, W. P. ;

Wurden, G. ;

Yu, J. .

NUCLEAR FUSION, 2007, 47 (09) :1086-1091

[3] Characterization of heat loads from mitigated and unmitigated vertical displacement events in DIII-D [J].

Hollmann, E. M. ;

Commaux, N. ;

Eidietis, N. W. ;

Humphreys, D. A. ;

Jernigan, T. J. ;

Lasnier, C. J. ;

Moyer, R. A. ;

Pitts, R. A. ;

Sugihara, M. ;

Strait, E. J. ;

Watkins, J. ;

Wesley, J. C. .

PHYSICS OF PLASMAS, 2013, 20 (06)

[4] Simulation of main chamber wall temperature rise resulting from massive neon gas injection shutdown of ITER [J].

Hollmann, E. M. ;

Humphreys, D. A. ;

Parks, P. B. .

NUCLEAR FUSION, 2012, 52 (03)

[5] Measurements of injected impurity assimilation during massive gas injection experiments in DIII-D [J].

Hollmann, E. M. ;

Jernigan, T. C. ;

Parks, P. B. ;

Boedo, J. A. ;

Evans, T. E. ;

Groth, M. ;

Humphreys, D. A. ;

James, A. N. ;

Lanctot, M. J. ;

Nishijima, D. ;

Rudakov, D. L. ;

Scott, H. A. ;

Strait, E. J. ;

Van Zeeland, M. A. ;

Wesley, J. C. ;

West, W. P. ;

Wu, W. ;

Yu, J. H. .

NUCLEAR FUSION, 2008, 48 (11)

[6] Experimental vertical stability studies for ITER performance and design guidance [J].

Humphreys, D. A. ;

Casper, T. A. ;

Eidietis, N. ;

Ferrara, M. ;

Gates, D. A. ;

Hutchinson, I. H. ;

Jackson, G. L. ;

Kolemen, E. ;

Leuer, J. A. ;

Lister, J. ;

LoDestro, L. L. ;

Meyer, W. H. ;

Pearlstein, L. D. ;

Portone, A. ;

Sartori, F. ;

Walker, M. L. ;

Welander, A. S. ;

Wolfe, S. M. .

NUCLEAR FUSION, 2009, 49 (11)

[7] Impurity mixing and radiation asymmetry in massive gas injection simulations of DIII-D [J].

Izzo, V. A. .

PHYSICS OF PLASMAS, 2013, 20 (05)

[8]

Lasnier C. J., 2011, P 53 APS DPP C SALT

[9] Impact and mitigation of disruptions with the ITER-like wall in JET [J].

Lehnen, M. ;

Arnoux, G. ;

Brezinsek, S. ;

Flanagan, J. ;

Gerasimov, S. N. ;

Hartmann, N. ;

Hender, T. C. ;

Huber, A. ;

Jachmich, S. ;

Kiptily, V. ;

Kruezi, U. ;

Matthews, G. F. ;

Morris, J. ;

Plyusnin, V. V. ;

Reux, C. ;

Riccardo, V. ;

Sieglin, B. ;

de Vries, P. C. .

NUCLEAR FUSION, 2013, 53 (09)

[10]

Maruyama S., 2010, IAEA FEC C

← 1 2 →