Speaker
Philip A. Schneider
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.1078.pdf
Experimental separation of ore transport and edge
pedestal isotope dependen ies by variation of the
plasma shape
P. A. S hneider1 , C. Angioni1 , M. Cavedon1 , M. G. Dunne1 , P. Hennequin2 , B. Kurzan1 ,
R. M. M Dermott1 , F. Ryter1 , M. Willensdorfer1 and the ASDEX Upgrade Team1
1
Max-Plan k-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Gar hing, Germany
2
Laboratoire de Physique des Plasmas, E ole Polyte hnique, Fran e
The mass dependen e of energy onnement in fusion plasmas is still not fully under-
stood. One of the main reasons is the di ulty of making dire t omparison studies.
Often the ause for this di ulty is multiple dierent me hanisms inuen ing onne-
ment. A variety of these me hanisms depending on the hydrogen isotope mass have been
reported on in the past [14℄. If not separated properly, understanding one of these me h-
anisms always relies on a urate knowledge of the others. In this ontribution we present
a possibility to separate the inuen e of the ore transport and the edge pedestal on
onnement.
In H-mode plasmas there are two major ontributions whi h determine the energy
onnement. The heat and parti le transport in the ore and the stability of the edge
transport barrier. Both are largely independent, so for transport studies the pedestal top
an be in good approximation regarded as boundary ondition. However, in experiments
with dierent isotopes, here hydrogen and deuterium, the assumption of the pedestal as
boundary ondition does not hold anymore. The reason for this is a strong degradation of
the pedestal in hydrogen ompared to deuterium for similar heat and parti le uxes. To
re over the quality of a boundary ondition the pedestal top values need to be mat hed
for omparable sour e terms. This an be a hieved by utilizing the ee t the plasma
triangularity has on the edge transport barrier.
We will present a variation of the shape between plasmas in hydrogen and deuterium
with mat hed edge onnement - meaning same pedestal top values for the same ion and
ele tron heat uxes as well as gas pu levels. The pedestal is then found to be lose
to peeling-ballooning stability for both isotopes. In the ore the plasma shows similar
transport properties when the heat uxes are mat hed despite the dierent isotopes.
Impli ations for the understanding of isotope dependen ies are dis ussed.
[1℄ BUSTOS, A. et al., Physi s of Plasmas 22 (2015) 012305.
[2℄ SCHNEIDER, P. A. et al., Nu lear Fusion 57 (2017) 66003.
[3℄ GARCIA, J. et al., Plasma Physi s and Controlled Fusion 59 (2017) 14023.
[4℄ LAGGNER, F. M. et al., Physi s of Plasmas 24 (2017) 56105.
