Experimental observations of bifurcated power decay lengths in the near Scrape-Off Layer of ST40 High Field Spherical Tokamak

Bibliographic Details
Title: Experimental observations of bifurcated power decay lengths in the near Scrape-Off Layer of ST40 High Field Spherical Tokamak
Authors: X. Zhang, C. Marsden, M. Moscheni, E.N.J. Maartensson, A. Rengle, M. Robinson, T. O’Gorman, H.F. Lowe, E. Vekshina, S. Janhunen, A. Scarabosio, P.F. Buxton, M. Sertoli, M. Romanelli, S.A.M. McNamara, T.K. Gray, N.A. Lopez
Source: Nuclear Materials and Energy, Vol 41, Iss , Pp 101772- (2024)
Publisher Information: Elsevier, 2024.
Publication Year: 2024
Collection: LCC:Nuclear engineering. Atomic power
Subject Terms: ST40 spherical tokamak, Plasma exhaust, Divertor heat flux, Scrape-off Layer width, Infrared thermography, Nuclear engineering. Atomic power, TK9001-9401
More Details: The scrape-off layer parallel heat flux decay lengths measured at ST40, a high field, low aspect ratio spherical tokamak, have been observed to bifurcate into two groups. The wide group follows established H-mode scalings (ranging between 2 to 8 mm) while the narrow group falls up to 10 times below these scalings (between 0.2 and 0.8 mm), being comparable to the ion total Larmor radius rather than the ion poloidal Larmor radius. The heat flux profiles of the latter group can only be described by a multi-exponential function, rather than the single exponential function convoluted with a Gaussian. The onset of the narrow scrape-off layer width is observed to be associated with suppressed magnetic fluctuations, suggesting reduced electromagnetic turbulence levels in the SOL.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2352-1791
Relation: http://www.sciencedirect.com/science/article/pii/S2352179124001959; https://doaj.org/toc/2352-1791
DOI: 10.1016/j.nme.2024.101772
Access URL: https://doaj.org/article/5bc1c3e945684c7094e2f3254b72cc19
Accession Number: edsdoj.5bc1c3e945684c7094e2f3254b72cc19
Database: Directory of Open Access Journals
More Details
ISSN:23521791
DOI:10.1016/j.nme.2024.101772
Published in:Nuclear Materials and Energy
Language:English