Power deposition on misaligned edges in COMPASS.

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F17%3A00481467" target="_blank" >RIV/61389021:_____/17:00481467 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.nme.2016.09.009" target="_blank" >http://dx.doi.org/10.1016/j.nme.2016.09.009</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.nme.2016.09.009" target="_blank" >10.1016/j.nme.2016.09.009</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Power deposition on misaligned edges in COMPASS.

Popis výsledku v původním jazyce

If the decision is made not to apply a toroidal chamfer to tungsten monoblocks at ITER divertor vertical targets, exposed leading edges will arise as a result of assembly tolerances between adjacent plasma-facing components. Then, the advantage of glancing magnetic field angles for spreading plasma heat flux on top surfaces is lost at the misaligned edges with an interaction occurring at near normal incidence, which can drive melting for the expected inter-ELM heat fluxes. A dedicated experiment has been performed on the COMPASS tokamak to thoroughly study power deposition on misaligned edges using inner-wall limited discharges on a special graphite tile presenting gaps and leading edges directly viewed by a high resolution infra-red camera. The parallel power flux deducted from the unperturbed measurement far from the gap is fully consistent with the observed temperature increase at the leading edge, respecting the power balance. All the power flowing into the gap is deposited at the leading edge and no mitigation factor is required to explain the thermal response. Particle-in-cell simulations show that the ion Larmor smoothing effect is weak and that the power deposition on misaligned edges is well described by the optical approximation because of an electron dominated regime associated with non-ambipolar parallel current flow.

Název v anglickém jazyce

Power deposition on misaligned edges in COMPASS.

Popis výsledku anglicky

If the decision is made not to apply a toroidal chamfer to tungsten monoblocks at ITER divertor vertical targets, exposed leading edges will arise as a result of assembly tolerances between adjacent plasma-facing components. Then, the advantage of glancing magnetic field angles for spreading plasma heat flux on top surfaces is lost at the misaligned edges with an interaction occurring at near normal incidence, which can drive melting for the expected inter-ELM heat fluxes. A dedicated experiment has been performed on the COMPASS tokamak to thoroughly study power deposition on misaligned edges using inner-wall limited discharges on a special graphite tile presenting gaps and leading edges directly viewed by a high resolution infra-red camera. The parallel power flux deducted from the unperturbed measurement far from the gap is fully consistent with the observed temperature increase at the leading edge, respecting the power balance. All the power flowing into the gap is deposited at the leading edge and no mitigation factor is required to explain the thermal response. Particle-in-cell simulations show that the ion Larmor smoothing effect is weak and that the power deposition on misaligned edges is well described by the optical approximation because of an electron dominated regime associated with non-ambipolar parallel current flow.

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

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Nuclear Materials and Energy

ISSN

2352-1791

e-ISSN

—

Svazek periodika

12

Číslo periodika v rámci svazku

August

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

5

Strana od-do

1374-1378

Kód UT WoS článku

000417293300230

EID výsledku v databázi Scopus

2-s2.0-84990842224