Speaker
Athina Kappatou
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/O2.105.pdf
CXRS measurements of energetic helium ions in ASDEX Upgrade
plasmas heated with a three-ion species ICRH scheme
A. Kappatou1, M. Weiland1, Ye. O. Kazakov2, B. Geiger1, R. Bilato1, V. Bobkov1,
R. Dux1, T. Pütterich1, R.M. McDermott1, the EUROfusion MST1 team*
and the ASDEX Upgrade team
1
Max-Planck-Institut für Plasmaphysik, Garching, Germany
2
Laboratory for Plasma Physics, LPP-ERM/KMS, Brussels, Belgium
Fast ion physics is an active field of research in the fusion community, but the studies
mostly focus on deuterium fast ions. The generation and investigation of energetic helium
in present devices, however, provide significantly more insight on how fast alpha particles,
produced from fusion reactions, will behave in future reactor plasmas. Apart from the
fusion-produced helium studies carried out at TFTR [1], such investigations have been
conducted in non-nuclear devices simulating the fast helium ion population either by
helium neutral beam injection [2], or by accelerating either 4He-beam ions [3] or 3He ions
[4] with ion cyclotron resonance heating (ICRH). Fast helium ion populations can be
measured with charge exchange recombination spectroscopy (CXRS) in the wings of the
helium spectral line (HeII n=4-3, 468.6nm), as was done in [1, 2, 4], providing information
on their distribution function.
In the present work, we present CXRS measurements of energetic 3He ions, obtained for
the first time at ASDEX Upgrade. These measurements were part of experiments
investigating the feasibility of a novel ‘three-ion’ ICRH scheme at ASDEX Upgrade [5, 6],
namely heating hydrogen-deuterium plasmas with a small amount of energetic 3He ions
generated with ICRH (energies on the order of 1MeV). The challenges of interpreting the
complex CXRS spectra are discussed. The information obtained is compared with the
theoretical predictions obtained with the TORIC-SSFPQL code [7]. Possible applications of
these measurements for energetic helium transport studies are considered.
[1] G.R. McKee et al, Nucl. Fusion 37, 501 (1997)
[2] M.G. von Hellermann et al, Plasma Phys. and Control. Fusion 35, 799 (1993)
[3] M.J. Mantsinen et al, Phys. Rev. Lett. 88, 105002 (2002)
[4] B.C. Stratton et al, Nucl. Fusion 34, 734 (1994)
[5] Ye.O. Kazakov et al, Nat. Phys. 13, 973 (2017)
[6] Ye.O. Kazakov et al, contribution submitted to the 27th IAEA Fusion Energy Conference (2018)
[7] R. Bilato et al, Nucl. Fusion 51, 103034 (2011)
* See the author list of H. Meyer et al., Nucl. Fusion 57, 102014 (2017)
