Profile measurements in the plasma edge of mega amp spherical tokamak using a ball pen probe

Walkden, N.R.; Adámek, Jiří; Allan, S.; Dudson, B.D.; Elmore, S.; Fishpool, G.; Harrison, J.; Kirk, A.; Komm, Michael

doi:https://dx.doi.org/10.1063/1.4908572

Number of the records: 1

Profile measurements in the plasma edge of mega amp spherical tokamak using a ball pen probe

1.

SYSNO ASEP	0443592
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Profile measurements in the plasma edge of mega amp spherical tokamak using a ball pen probe
Author(s)	Walkden, N.R. (GB) Adámek, Jiří (UFP-V)_{RID, ORCID} Allan, S. (GB) Dudson, B.D. (GB) Elmore, S. (GB) Fishpool, G. (GB) Harrison, J. (GB) Kirk, A. (GB) Komm, Michael (UFP-V)_{RID, ORCID}
Article number	023510
Source Title	Review of Scientific Instruments. - : AIP Publishing - ISSN 0034-6748 Roč. 86, č. 2 (2015)
Number of pages	9 s.
Publication form	Print - P
Language	eng - English
Country	US - United States
Keywords	plasma ; tokamak ; ball pen probe
Subject RIV	BL - Plasma and Gas Discharge Physics
OECD category	2.11 Other engineering and technologies
R&D Projects	GAP205/12/2327 GA ČR - Czech Science Foundation (CSF)
	LM2011021 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
Institutional support	UFP-V - RVO:61389021
UT WOS	000350552700029
EID SCOPUS	84923899679
DOI	10.1063/1.4908572
Annotation	The ball pen probe (BPP) technique is used successfully to make profile measurements of plasma potential, electron temperature, and radial electric field on the Mega Amp Spherical Tokamak. The potential profile measured by the BPP is shown to significantly differ from the floating potential both in polarity and profile shape. By combining the BPP potential and the floating potential, the electron temperature can be measured, which is compared with the Thomson scattering (TS) diagnostic. Excellent agreement between the two diagnostics is obtained when secondary electron emission is accounted for in the floating potential. From the BPP profile, an estimate of the radial electric field is extracted which is shown to be of the order ~1 kV/mand increases with plasma current. Corrections to the BPP measurement, constrained by the TS comparison, introduce uncertainty into the ER measurements. The uncertainty is most significant in the electric field well inside the separatrix.
Workplace	Institute of Plasma Physics
Contact	Vladimíra Kebza, kebza@ipp.cas.cz, Tel.: 266 052 975
Year of Publishing	2016

Number of the records: 1