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Post-disruptive runaway electron beams in the COMPASS tokamak

Part of: Focus on Fusion Energetic Electrons

Published online by Cambridge University Press:  11 August 2015

Milos Vlainic ,
J. Mlynar ,
J. Cavalier ,
V. Weinzettl ,
R. Paprok ,
M. Imrisek ,
O. Ficker ,
M. Varavin ,
P. Vondracek  and
J.-M. Noterdaeme
...Show all authors
Milos Vlainic*
Affiliation:
Department of Applied Physics, Ghent University, Ghent 9000, Belgium Institute of Plasma Physics AS CR, Prague 18200, Czech Republic
J. Mlynar
Affiliation:
Institute of Plasma Physics AS CR, Prague 18200, Czech Republic
J. Cavalier
Affiliation:
Institute of Plasma Physics AS CR, Prague 18200, Czech Republic
V. Weinzettl
Affiliation:
Institute of Plasma Physics AS CR, Prague 18200, Czech Republic
R. Paprok
Affiliation:
Institute of Plasma Physics AS CR, Prague 18200, Czech Republic Faculty of Mathematics and Physics, Charles University, Prague 12116, Czech Republic
M. Imrisek
Affiliation:
Institute of Plasma Physics AS CR, Prague 18200, Czech Republic Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Prague 11519, Czech Republic
O. Ficker
Affiliation:
Institute of Plasma Physics AS CR, Prague 18200, Czech Republic Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Prague 11519, Czech Republic
M. Varavin
Affiliation:
Institute of Plasma Physics AS CR, Prague 18200, Czech Republic
P. Vondracek
Affiliation:
Institute of Plasma Physics AS CR, Prague 18200, Czech Republic
J.-M. Noterdaeme
Affiliation:
Department of Applied Physics, Ghent University, Ghent 9000, Belgium Max Planck Institute for Plasma Physics, Garching 85748, Germany
*
†Email address for correspondence: [email protected]
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Abstract

For ITER-relevant runaway electron studies, such as suppression, mitigation, termination and/or control of a runaway beam, it is important to obtain the runaway electrons after the disruption. In this paper we report on the first discharges achieved with a post-disruptive runaway electron beam, termed a ‘runaway plateau’, in the COMPASS tokamak. The runaway plateau is produced by a massive gas injection of argon. Almost all of the disruptions with runaway electron plateaus occurred during the plasma current ramp-up phase. The Ar injection discharges with and without a runaway plateau were compared for various parameters. Parametrisation of the discharges shows that the COMPASS disruptions fulfil the range of parameters important for runaway plateau occurrence. These parameters include electron density, electric field, disruption speed, effective safety factor, and the maximum current quench electric field. In addition to these typical parameters, the plasma current value just before the massive gas injection proved to be surprisingly important.

Type
Research Article
Information
Journal of Plasma Physics , Volume 81 , Issue 5 , October 2015 , 475810506
Copyright
© The Author(s) 2015 

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References

Connor, J. W. & Hastie, R. J. 1975 Relativistic limitations on runaway electrons. Nucl. Fusion 15 (3), 415–424.Google Scholar
Decker, J. & Peysson, Y.2004, DKE: a fast numerical solver for the 3-D relativistic bounce-averaged electron Drift Kinetic Equation. Tech. Rep. EUR-CEA-FC-1736, Plasma Science and Fusion Center, MIT.Google Scholar
Dreicer, H. 1959 Electron and ion runaway in a fully ionized gas. Part I. Phys. Rev. 115, 238–249.Google Scholar
Dreicer, H. 1960 Electron and ion runaway in a fully ionized gas. Part II. Phys. Rev. 117, 329–342.Google Scholar
Esposito, B., Martín-Solís, J. R., Poli, F. M., Mier, J. A., Sánchez, R. & Panaccione, L. 2003 Dynamics of high energy runaway electrons in the Frascati Tokamak Upgrade. Phys. Plasmas 10 (6), 2350–2360.Google Scholar
Fredrickson, E. D., Bell, M. G., Taylor, G. & Medley, S. S. 2015 Control of disruption-generated runaway plasmas in TFTR. Nucl. Fusion 55 (1), 013006.Google Scholar
Gill, R. D., Alper, B., de Baar, M., Hender, T. C., Johnson, M. F., Riccardo, V.& contributors to the EFDA-JET Workprogramme 2002 Behaviour of disruption generated runaways in JET. Nucl. Fusion 42 (8), 1039–1044.Google Scholar
Gill, R. D., Alper, B., Edwards, A. W., Ingesson, L. C., Johnson, M. F. & Ward, D. J. 2000 Direct observations of runaway electrons during disruptions in the JET tokamak. Nucl. Fusion 40 (2), 163–174.Google Scholar
Havlíček, J. & Hronová, O. 2008 Characterization of magnetic fields in the COMPASS tokamak. In WDS’08 Proceedings of Contributed Papers, Charles University.Google Scholar
Havlíček, J. & Hronová, O.2010, Magnetic diagnostics of COMPASS tokamak:http://www.ipp.cas.cz/tokamak/euratom/index.php/en/compass-diagnostics/magnetic-diagnostics.Google Scholar
Hender, T. C., Wesley, J. C., Bialek, J., Bondeson, A., Boozer, A. H., Buttery, R. J., Garofalo, A., Goodman, T. P., Granetz, R. S., Gribov, Y., Gruber, O., Gryaznevich, M., Giruzzi, G., Günter, S., Hayashi, N., Helander, P., Hegna, C. C., Howell, D. F., Humphreys, D. A., Huysmans, G. T. A., Hyatt, A. W., Isayama, A., Jardin, S. C., Kawano, Y., Kellman, A., Kessel, C., Koslowski, H. R., La Haye, R. J., Lazzaro, E., Liu, Y. Q., Lukash, V., Manickam, J., Medvedev, S., Mertens, V., Mirnov, S. V., Nakamura, Y., Navratil, G., Okabayashi, M., Ozeki, T., Paccagnella, R., Pautasso, G., Porcelli, F., Pustovitov, V. D., Riccardo, V., Sato, M., Sauter, O., Schaffer, M. J., Shimada, M., Sonato, P., Strait, E. J., Sugihara, M., Takechi, M., Turnbull, A. D., Westerhof, E., Whyte, D. G., Yoshino, R., Zohm, H.& the ITPA MHD, Disruption and Magnetic Control Topical Group 2007 Chapter 3: MHD stability, operational limits and disruptions. Nucl. Fusion 47 (6), S128–S202.Google Scholar
Hollmann, E. M., Austin, M. E., Boedo, J. A., Brooks, N. H., Commaux, N., Eidietis, N. W., Humphreys, D. A., Izzo, V. A., James, A. N., Jernigan, T. C., Loarte, A., Martín-Solís, J. R., Moyer, R. A., Muñoz-Burgos, J. M., Parks, P. B., Rudakov, D. L., Strait, E. J., Tsui, C., Van Zeeland, M. A., Wesley, J. C. & Yu, J. H. 2013 Control and dissipation of runaway electron beams created during rapid shutdown experiments in DIII-D. Nucl. Fusion 53 (8), 083004.Google Scholar
Janky, F., Havlíček, J., Batista, A. J. N., Kudlacek, O., Seidl, J., Neto, A. C., Pipek, J., Hron, M., Mikulin, O., Duarte, A. S., Carvalho, B. B., Stockel, J. & Panek, R. 2014 Upgrade of the COMPASS tokamak real-time control system. Fusion Engng Des. 89 (3), 186–194; Design and implementation of real-time systems for magnetic confined fusion devices.Google Scholar
Kocmanová, L.2012, Runaway electrons in the tokamak and their detection. Diploma thesis, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Prague, Czech Republic. See http://geraldine.fjfi.cvut.cz/archiv-praci/magisterske-FI-FTTF [cit. 21.5.2015].Google Scholar
Kuznetsov, Yu. K., Galvão, R. M. O., Bellintani, V. Jr, Ferreira, A. A., Fonseca, A. M. M., Nascimento, I. C., Ruchko, L. F., Saettone, E. A. O., Tsypin, V. S. & Usuriaga, O. C. 2004 Runaway discharges in TCABR. Nucl. Fusion 44 (5), 631–644.Google Scholar
Loarte, A., Riccardo, V., Martín-Solís, J. R., Paley, J., Huber, A., Lehnen, M.& JET EFDA Contributors 2011 Magnetic energy flows during the current quench and termination of disruptions with runaway current plateau formation in JET and implications for ITER. Nucl. Fusion 51 (7), 073004.Google Scholar
Martin, G., Chatelier, M. & Doloc, C. 1995 New insight into runaway electrons production and confinement. In 22nd EPS Conference on Plasma Physics, Bournemouth, UK, Plasma Phys. Control. Fusion.Google Scholar
Martín-Solís, J. R., Loarte, A., Hollmann, E. M., Esposito, B., Riccardo, V.& FTU, Teams, DIII-D & JET EFDA Contributors 2014 Inter-machine comparison of the termination phase and energy conversion in tokamak disruptions with runaway current plateau formation and implications for ITER. Nucl. Fusion 54 (8), 083027.Google Scholar
Martín-Solís, J. R., Sánchez, R. & Esposito, B. 2010 Experimental observation of increased threshold electric field for runaway generation due to synchrotron radiation losses in the FTU tokamak. Phys. Rev. Lett. 105, 185002.Google Scholar
Nilsson, E., Decker, J., Peysson, Y., Granetz, R. S., Saint-Laurent, F. & Vlainić, M. 2015 Kinetic modelling of runaway electron avalanches in tokamak plasmas. Plasma Phys. Control. Fusion (in press).Google Scholar
Pánek, R., Adámek, J., Aftanas, M., Bílková, P., Böhm, P., Cahyna, P., Cavalier, J., Dejarnac, R., Dimitrova, M., Grover, O., Háček, P., Havlíček, J., Havránek, A., Horáček, J., Hron, M., Imríšek, M., Janky, F., Komm, M., Kovařík, K., Krbec, J., Kripner, L., Markovič, T., Mitošinková, K., Mlynář, J., Naydenkova, D., Peterka, M., Seidl, J., Stöckel, J., Štefániková, E., Tomeš, M., Urban, J., Vondráček, P., Varavin, M., Varju, J., Weinzettl, V., Zajac, J.& The COMPASS Team 2015 Status of the COMPASS tokamak and characterization of the first H-mode. Plasma Phys. Control. Fusion – Invited talk at EPS Conference on Plasma Physics (submitted).Google Scholar
Papřok, R., Krlín, L. & Stöckel, J. 2013 Observation and prediction of runaway electrons in the COMPASS tokamak. In WDS’13 Proceedings of Contributed Papers, Charles University.Google Scholar
Plyusnin, V. V., Reux, C., Kiptily, V. G., Shevelev, A. E., Mlynar, J., Lehnen, M., de Vries, P. C., Khilkevitch, E. M., Huber, A., Sergienko, G., Pereira, R. C., Alves, D., Alper, B., Kruezi, U., Jachmich, S., Fernandes, A., Brix, M., Riccardo, V., Giacomelli, L., Sozzi, C., Gerasimov, S., Manzanares, A., de La Luna, E., Boboc, A., Matthews, G. F.& JET Contributors 2014 Parameters of runaway electrons in JET. In 25th IAEA Fusion Energy Conference; preprint EFDA-JET-CP(14)06/34 at http://www.euro-fusionscipub.org/jetarchive [cit. 21.5.2015].Google Scholar
Reux, C., Plyusnin, V., Alper, B., Alves, D., Bazylev, B., Belonohy, E., Brezinsek, S., Decker, J., Devaux, S., de Vries, P., Fil, A., Gerasimov, S., Lupelli, I., Jachmich, S., Khilkevitch, E. M., Kiptily, V., Koslowski, R., Kruezi, U., Lehnen, M., Manzanares, A., Mlynář, J., Nardon, E., Nilsson, E., Riccardo, V., Saint-Laurent, F., Shevelev, A. E., Sozzi, C.& JET EFDA Contributors 2014 Runaway beam studies during disruptions at JET-ILW. In 21st International Conference on Plasma Surface Interactions; J. Nucl. Mater. 463, 143–149.Google Scholar
Rosenbluth, M. N. & Putvinski, S. V. 1997 Theory for avalanche of runaway electrons in tokamaks. Nucl. Fusion 37 (10), 1355–1362.Google Scholar
Saint-Laurent, F., Bucalossi, J., Reux, C., Bremond, S., Douai, D., Gil, C. & Moreau, P. 2011 Control of runaway electron beam heat loads on Tore Supra. In 38th EPS Conference on Plasma Physics, Plasma Phys. Control. Fusion.Google Scholar
Saint-Laurent, F., Reux, C., Bucalossi, J., Loarte, A., Bremond, S., Gil, C. & Moreau, P. 2009 Control of runaway electron beams on Tore Supra. In 36th EPS Conference on Plasma Physics, Plasma Phys. Control. Fusion.Google Scholar
Smith, H. M. & Verwichte, E. 2008 Hot tail runaway electron generation in tokamak disruptions. Phys. Plasmas 15 (7), 072502.Google Scholar
Vlainić, M., Mlynář, J., Weinzettl, V., Papřok, R., Imrísek, M., Ficker, O., Vondráček, P. & Havlíček, J. 2015 First dedicated observations of runaway electrons in COMPASS tokamak. Nukleonika 60 (2).Google Scholar
Yoshino, R., Tokuda, S. & Kawano, Y. 1999 Generation and termination of runaway electrons at major disruptions in JT-60U. Nucl. Fusion 39 (2), 151–161.Google Scholar
Yu, J. H., Hollmann, E. M., Commaux, N., Eidietis, N. W., Humphreys, D. A., James, A. N., Jernigan, T. C. & Moyer, R. A. 2013 Visible imaging and spectroscopy of disruption runaway electrons in DIII-D. Phys. Plasmas 20 (4), 042113.Google Scholar