TY  - JOUR
AU  - Cai, J.
AU  - Liang, Yunfeng
AU  - Killer, C.
AU  - Liu, S.
AU  - Hiller, A.
AU  - Knieps, A.
AU  - Schweer, B.
AU  - Höschen, D.
AU  - Nicolai, D.
AU  - Offermanns, G.
AU  - Satheeswaran, G.
AU  - Henkel, Marion
AU  - Hollfeld, K.
AU  - Grulke, O.
AU  - Drews, P.
AU  - Krings, T.
AU  - Li, Y.
TI  - A new multi-channel Mach probe measuring the radial ion flow velocity profile in the boundary plasma of the W7-X stellarator
JO  - Review of scientific instruments
VL  - 90
IS  - 3
SN  - 1089-7623
CY  - [S.l.]
PB  - American Institute of Physics
M1  - FZJ-2021-01510
SP  - 033502 -
PY  - 2019
AB  - Ion flow velocity measurement in the edge and scraper-off layer region is beneficial to understand the confinement related phenomenon in fusion devices such as impurity transport and plays an important role in impurity control. During the Wendelstein 7-X (W7-X) operation phase 1.2a, a multi-channel (MC) Mach probe mounted on the multi-purpose manipulator has been used to measure radial profiles of edge ion flow velocity. This MC-Mach probe consists of two polar and two radial arrays of directional Langmuir pins (28 pins in total) serving for different aims, of which the polar arrays could obtain a polar distribution of ion saturation current, while the radial arrays can be used to study the dynamic process of a radially propagated event. In this paper, we report the observation of the radially outward propagation of a low frequency mode with a speed of around 200 m/s. The first measurement of the radial ion flow velocity profile using the MC-Mach probe in the boundary plasma of the W7-X with an island divertor will also be presente
LB  - PUB:(DE-HGF)16
C6  - 30927788
UR  - <Go to ISI:>//WOS:000462917300017
DO  - DOI:10.1063/1.5054279
UR  - https://juser.fz-juelich.de/record/891425
ER  -