Energetic ions in ITER plasmas

Journal Article · Sun Feb 15 00:00:00 EST 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4908551· OSTI ID:22408052

Pinches, S. D. ^[1]; Chapman, I. T.; Sharapov, S. E. ^[2]; Lauber, Ph. W. ^[3]; Oliver, H. J. C. ^[4]; Shinohara, K. ^[5]; Tani, K. ^[6]

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1. ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul-lez-Durance Cedex (France)
2. CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom)
3. Max-Planck-Institut für Plasmaphysik, EURATOM-Association, Boltzmanstraße 2, D-85748 Garching (Germany)
4. H H Wills Physics Laboratory, University of Bristol, Royal Fort, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)
5. Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan)
6. Nippon Advanced Technology Co., Ltd, Naka, Ibaraki 311-0102 (Japan)

This paper discusses the behaviour and consequences of the expected populations of energetic ions in ITER plasmas. It begins with a careful analytic and numerical consideration of the stability of Alfvén Eigenmodes in the ITER 15 MA baseline scenario. The stability threshold is determined by balancing the energetic ion drive against the dominant damping mechanisms and it is found that only in the outer half of the plasma (r/a>0.5) can the fast ions overcome the thermal ion Landau damping. This is in spite of the reduced numbers of alpha-particles and beam ions in this region but means that any Alfvén Eigenmode-induced redistribution is not expected to influence the fusion burn process. The influence of energetic ions upon the main global MHD phenomena expected in ITER's primary operating scenarios, including sawteeth, neoclassical tearing modes and Resistive Wall Modes, is also reviewed. Fast ion losses due to the non-axisymmetric fields arising from the finite number of toroidal field coils, the inclusion of ferromagnetic inserts, the presence of test blanket modules containing ferromagnetic material, and the fields created by the Edge Localised Mode (ELM) control coils in ITER are discussed. The greatest losses and associated heat loads onto the plasma facing components arise due to the use of the ELM control coils and come from neutral beam ions that are ionised in the plasma edge.

• OSTI ID: 22408052
• Journal Information: Physics of Plasmas, Vol. 22, Issue 2; Other Information: (c) 2015 EURATOM; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
ALPHA PARTICLES
AXIAL SYMMETRY
CONTROL
EDGE LOCALIZED MODES
EIGENFREQUENCY
FERROMAGNETIC MATERIALS
FIRST WALL
HEATING LOAD
ION BEAMS
ITER TOKAMAK
LANDAU DAMPING
MAGNETOHYDRODYNAMICS
PARTICLE LOSSES
PLASMA
SAWTOOTH OSCILLATIONS
TAIL IONS
TEARING INSTABILITY