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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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

Název v anglickém jazyce

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

Popis výsledku anglicky

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

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

<a href="/cs/project/GA15-10723S" target="_blank" >GA15-10723S: Rychlé měření tepelného toku v divertorové oblasti na tokamaku COMPASS pomocí ball-pen sond se sub-mikrosekundovým časovým rozlišením.</a><br>

Návaznosti

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

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Nuclear Fusion

ISSN

0029-5515

e-ISSN

—

Svazek periodika

57

Číslo periodika v rámci svazku

12

Stát vydavatele periodika

AT - Rakouská republika

Počet stran výsledku

17

Strana od-do

126029

Kód UT WoS článku

000411702700003

EID výsledku v databázi Scopus

2-s2.0-85029934892