Understanding and suppressing the near Scrape-Off Layer in inboard-limited plasmas in TCV.

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F17%3A00484465" target="_blank" >RIV/61389021:_____/17:00484465 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1088/1741-4326/aa84e0" target="_blank" >http://dx.doi.org/10.1088/1741-4326/aa84e0</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1741-4326/aa84e0" target="_blank" >10.1088/1741-4326/aa84e0</a>

Result language

angličtina

Original language name

Understanding and suppressing the near Scrape-Off Layer in inboard-limited plasmas in TCV.

Original language description

In inboard-limited plasmas, the scrape-off layer (SOL) shows two regions: the near SOL, extending a few mm from the last closed flux surface (LCFS), characterized by a steep gradient of the parallel heat flux radial profile, and a far SOL, typically some cm wide, with flatter heat flux profiles. The physics of the near SOL is investigated in TCV with two series of experiments featuring deuterium and helium plasmas, in which the plasma current, density and elongation have been varied. The parallel heat flux profiles are measured on the limiter by means of infrared thermography. For the first time, the near SOL is reported to disappear for low plasma current or at high density, for values of the SOL collisionality ν SOL corresponding to a conduction-limited regime. The power in the near SOL ΔPSOL is shown to decrease with the normalized Spitzer resistivity v as PSOL alpha ν-1. The floating potential profiles, measured at the limiter using flush-mounted Langmuir probes (LP), show the presence of non-ambipolar currents, and their relation to the presence of a velocity shear layer is discussed. The shearing rate is shown to strictly correlate with the power in the near SOL PSOL, consistently with a recent theoretical model. Measurements of the near SOL on the Low Field Side (LFS) are performed using a reciprocating Langmuir probe (RP). The near SOL is reported to vanish simultaneously at the LFS and at the limiter. The near and far SOL widths are compared with the predictions from existing theoretical models, to which empirical corrections with resistivity and elongation are proposed

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

<a href="/en/project/GA15-10723S" target="_blank" >GA15-10723S: Fast heat flux measurements in divertor region in tokamak COMPASS using ball-pen probes with sub-microsecond temporal resolution.</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Nuclear Fusion

ISSN

0029-5515

e-ISSN

—

Volume of the periodical

57

Issue of the periodical within the volume

12

Country of publishing house

AT - AUSTRIA

Number of pages

17

Pages from-to

126029

UT code for WoS article

000411702700003

EID of the result in the Scopus database

2-s2.0-85029934892