High-heat flux ball-pen probe head in ASDEX-Upgrade

0555630 - ÚFP 2022 RIV US eng J - Journal Article
Grenfell, G. - Adámek, Jiří - Komm, Michael - Brida, D. - Conway, G.D. - Manz, P. - Tolias, P. - Eich, T. - Šesták, David - Herrmann, A. - Nishizawa, T. - Stroth, U.
High-heat flux ball-pen probe head in ASDEX-Upgrade.
Review of Scientific Instruments. Roč. 93, č. 2 (2022), s. 023507. ISSN 0034-6748. E-ISSN 1089-7623
R&D Projects: GA MŠMT(CZ) LM2018117; GA MŠMT(CZ) EF16_019/0000768
Institutional support: RVO:61389021
Keywords : ASDEX-Upgrade * tokamak * ball-pen probe
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 1.6, year: 2022
Method of publishing: Limited access
https://aip.scitation.org/doi/10.1063/5.0075846

A new high heat flux ball-pen probe head installed on the midplane manipulator is currently being used in ASDEX-Upgrade (AUG). The probe was designed to withstand high heat fluxes making possible the investigation of the plasma edge under harsh conditions, such as low power H-mode. Composed of seven pins (four Langmuir probes, mounted in two Mach probe pairs, and three ball-pen probes), the new probe head allows us to measure several plasma parameters simultaneously and with high temporal resolution. A novel method to correct the sheath potential dynamically accounting for the total secondary electron emission is introduced together with applications to obtain the electron temperature and plasma potential profiles. The total secondary electron emission yield is obtained from particle in cell simulations in AUG condition and probe realistic impact angle with respect to the magnetic field. Finally, the probe capability to investigate turbulence around the separatrix of AUG is discussed.
Permanent Link: http://hdl.handle.net/11104/0330081