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Experimental observation of hot tail runaway electron generation in TEXTOR disruptions

Published online by Cambridge University Press:  14 April 2015

L. Zeng*
Affiliation:
Institute of Plasma Physics, Chinese Academy of Sciences, 230031 Hefei, China
H. R. Koslowski
Affiliation:
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Plasma Physics (IEK-4), 52425 Jülich, Germany
Y. Liang
Affiliation:
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Plasma Physics (IEK-4), 52425 Jülich, Germany
A. Lvovskiy
Affiliation:
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Plasma Physics (IEK-4), 52425 Jülich, Germany
M. Lehnen
Affiliation:
ITER Organization, Route de Vinon sur Verdon, 13115 St Paul Lez Durance, France
D. Nicolai
Affiliation:
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Plasma Physics (IEK-4), 52425 Jülich, Germany
J. Pearson
Affiliation:
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Plasma Physics (IEK-4), 52425 Jülich, Germany
M. Rack
Affiliation:
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Plasma Physics (IEK-4), 52425 Jülich, Germany
P. Denner
Affiliation:
Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Plasma Physics (IEK-4), 52425 Jülich, Germany
K. H. Finken
Affiliation:
Institut für Laser- und Plasmaphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
K. Wongrach
Affiliation:
Institut für Laser- und Plasmaphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
*
Email address for correspondence: [email protected]

Abstract

Experimental evidence supporting the theory of hot tail runaway electron (RE) generation has been identified in TEXTOR disruptions. With higher temperature, more REs are generated during the thermal quench. Increasing the RE generation by increasing the temperature, an obvious RE plateau is observed even with low toroidal magnetic field (1.7 T). These results explain the previously found electron density threshold for RE generation.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2015 

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References

REFERENCES

Bozhenkov, S. A. et al. 2007 Main characteristics of the fast disruption mitigation valve. Rev. Sci. Instrum. 78, 033503.Google Scholar
Bozhenkov, S. A. et al. 2008 Generation and suppression of runaway electrons in disruption mitigation experiments in TEXTOR. Plasma Phys. Control. Fusion 50, 105007.Google Scholar
Chiu, S. C., Rosenbluth, M. N., Harvey, R. W. and Chan, V. S. 1998 Fokker–Planck simulations mylb of knock-on electron runaway avalanche and bursts in tokamaks. Nucl. Fusion 38, 1711.Google Scholar
Connor, J. W., Hastie, R. J. 1975 Relativistic limitations on runaway electrons. Nucl. Fusion 15, 415.Google Scholar
Dreicer, H. 1959 Electron and ion runaway in a fully ionized gas: I. Phys. Rev. 115, 238.Google Scholar
Dreicer, H. 1960 Electron and ion runaway in a fully ionized gas: II. Phys. Rev. 117, 329.Google Scholar
Féher, T. et al. 2011 Simulation of runaway electron generation during plasma shutdown by impurity injection in ITER. Plasma Phys. Control. Fusion 53, 035014.Google Scholar
Granetz, R. et al. 2015 An ITPA joint experiment to study runaway electron generation and suppression. Phys. Plasma 21, 072506.Google Scholar
Harvey, R. W. et al. 2000 Runaway electron production in DIII-D killer pellet experiments, calculated with the CQL3D/KPRAD model. Phys. Plasmas 7, 4590.Google Scholar
Helander, P., Smith, H., Fülop, T. and Eriksson, L. G. 2004 Electron kinetics in a cooling plasma. Phys. Plasmas 11, 5704.Google Scholar
Hender, T. C. et al. 2007 Progress in the ITER physics basis chapter 3: MHD stability, operational limits and disruptions. Nucl. Fusion 47, S128.Google Scholar
ITER Physics Basis Editors et al. 1999 ITER physics basis chapter 1: overview and summary. Nucl. Fusion 39, 2137.Google Scholar
James, A. N. 2011 Investigations of runaway electron generation, transport, and stability in the DIII-D tokamak. PhD thesis, University of California, San Diego, USA.Google Scholar
James, A. N. et al. 2012 Measurements of hard x-ray emission from runaway electrons in DIII-D. Nucl. Fusion 52, 013007.Google Scholar
Lehnen, M. et al. 2008 Suppression of runaway electrons by resonant magnetic perturbations in TEXTOR disruptions. Phys. Rev. Lett. 100, 255003.Google Scholar
Lehnen, M. et al. 2009 Runaway generation during disruptions in JET and TEXTOR. J. Nucl. Mater. 390–391, 740.Google Scholar
Lehnen, M. et al. 2011 Disruption mitigation by massive gas injection in JET. Nucl. Fusion 51, 123010.Google Scholar
Lvovskiy, A. Koslowski, H. R. and Zeng, L. 2015 Suppression of the runaway electron generation by massive gas injection after induced disruptions on TEXTOR. Submitted to J. Plasma Phys.Google Scholar
Marmar, E. et al. 2009 Overview of the Alcator C-Mod research program. Nucl. Fusion 49, 104014.Google Scholar
Martin, G. 1998 Runaway electrons: from Tore-Supra to ITER. In: Proc. 25th European Physical Society Conf. on Plasma Physics, Prague, 1998, Vol. 22C. Prague, Czech Republic: European Physical Society, P3.006.Google Scholar
Pautasso, G. et al. 2007 Plasma shut-down with fast impurity puff on ASDEX Upgrade. Nucl. Fusion 47, 900.Google Scholar
Rosenbluth, M. N. and Putvinski, S. V. 1997 Theory for avalanche of runaway electrons in tokamaks. Nucl. Fusion 37, 1355.Google Scholar
Smith, H., Helander, P., Eriksson, L. G. and Fülop, T. 2005 Runaway electron generation in a cooling plasma. Phys. Plasmas 12, 122505.Google Scholar
Smith, H. and Verwichte, E. 2008 Hot tail runaway electron generation in tokamak disruptions. Phys. Plasmas 15, 072502.Google Scholar
Thornton, A. J. et al. 2012 Plasma profile evolution during disruption mitigation via massive gas injection on MAST. Nucl. Fusion 52, 063018.Google Scholar
Yoshino, R. 1995 Avoidance and softening of disruptions by control of plasma-surface interaction. J. Nucl. Mater. 220–222, 132.Google Scholar
Yoshino, R., Tokuda, S. and Kawano, Y. 1999 Generation and termination of runaway electrons at major disruptions in JT-60U. Nucl. Fusion 39, 151.Google Scholar
Zeng, L. et al. 2013 Experimental observation of a magnetic-turbulence threshold for runaway-electron generation in the TEXTOR tokamak. Phys. Rev. Lett. 110, 235003.Google Scholar