TY - JOUR
T1 - Implications of high density operation on SOL transport
T2 - A multimachine investigation
AU - ASDEX Upgrade Team
AU - COMPASS team
AU - JET-EFDA Contributors
AU - Carralero, D.
AU - Müller, H. W.
AU - Groth, M.
AU - Komm, M.
AU - Adamek, J.
AU - Birkenmeier, G.
AU - Brix, M.
AU - Janky, F.
AU - Hacek, P.
AU - Marsen, S.
AU - Reimold, F.
AU - Silva, C.
AU - Stroth, U.
AU - Wischmeier, M.
AU - Wolfrum, E.
N1 - Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2015/7/22
Y1 - 2015/7/22
N2 - Abstract The transition reported in L-mode plasmas leading to the formation of a density "shoulder" in the Scrape-off Layer (SOL) of tokamaks is investigated in the three ITER stepladder machines: COMPASS, ASDEX Upgrade (AUG) and JET. In AUG and JET, the broadening of the profiles can be observed at similar relative densities (ne/nGW ∼ 0.4-0.5) and coincides with a clear increase in the size of SOL filaments and the onset of the outer divertor detachment. In COMPASS, no transition is observed in the same density range: the divertor does not detach and no clear effect is observed neither in the profiles nor in the turbulence. This is explained as the result of an increase of intermittent transport triggered by the increased resistivity along filaments associated to divertor detachment. The transition conditions in AUG and JET are compared to foreseen ITER SOL parameters, and the implications are briefly discussed.
AB - Abstract The transition reported in L-mode plasmas leading to the formation of a density "shoulder" in the Scrape-off Layer (SOL) of tokamaks is investigated in the three ITER stepladder machines: COMPASS, ASDEX Upgrade (AUG) and JET. In AUG and JET, the broadening of the profiles can be observed at similar relative densities (ne/nGW ∼ 0.4-0.5) and coincides with a clear increase in the size of SOL filaments and the onset of the outer divertor detachment. In COMPASS, no transition is observed in the same density range: the divertor does not detach and no clear effect is observed neither in the profiles nor in the turbulence. This is explained as the result of an increase of intermittent transport triggered by the increased resistivity along filaments associated to divertor detachment. The transition conditions in AUG and JET are compared to foreseen ITER SOL parameters, and the implications are briefly discussed.
UR - http://www.scopus.com/inward/record.url?scp=84937729513&partnerID=8YFLogxK
U2 - 10.1016/j.jnucmat.2014.10.019
DO - 10.1016/j.jnucmat.2014.10.019
M3 - Article
AN - SCOPUS:84937729513
SN - 0022-3115
VL - 463
SP - 123
EP - 127
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
M1 - 48516
ER -