Measurement and modelling of suprathermal electron bursts generated in front of a lower hybrid antenna

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F16%3A00459865" target="_blank" >RIV/61389021:_____/16:00459865 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1088/0029-5515/56/3/036004" target="_blank" >http://dx.doi.org/10.1088/0029-5515/56/3/036004</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/0029-5515/56/3/036004" target="_blank" >10.1088/0029-5515/56/3/036004</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Measurement and modelling of suprathermal electron bursts generated in front of a lower hybrid antenna

Popis výsledku v původním jazyce

Measurements in the tokamak scrape-off layer show the existence of fast electrons as far as a few centimeters radially in front of a lower hybrid antenna grill, which is one order of magnitude further than earlier predictions of interaction zones not exceeding 5 mm in width (Rantamaki et al 2000 Nucl. Fusion 40 1477). The present contribution aims at understanding these experimental results on the basis of electron Landau damping in a turbulent scrape-off layer. A crucial guiding element from the experiments is the observation of temporal intermittency of the fast electron signal at positions radially away from the grill mouth at a rate comparable with the detachment rate of relatively hot and dense field-aligned plasma filaments, or 'blobs,' from the last closed flux surface. When the dynamic character of the scrape-off layer is taken into account, transient low density and low temperature states occur during which the Landau damping can be weak enough to allow the radiated spectrum to penetrate radially deep inward. When the lower hybrid wave intercepts a dense and hot 'blob' a few cm in front of the antenna, then strong damping of the high wave number components can occur. This is the scenario we propose for explaining the generation of fast electrons far away from the grill mouth.

Název v anglickém jazyce

Measurement and modelling of suprathermal electron bursts generated in front of a lower hybrid antenna

Popis výsledku anglicky

Measurements in the tokamak scrape-off layer show the existence of fast electrons as far as a few centimeters radially in front of a lower hybrid antenna grill, which is one order of magnitude further than earlier predictions of interaction zones not exceeding 5 mm in width (Rantamaki et al 2000 Nucl. Fusion 40 1477). The present contribution aims at understanding these experimental results on the basis of electron Landau damping in a turbulent scrape-off layer. A crucial guiding element from the experiments is the observation of temporal intermittency of the fast electron signal at positions radially away from the grill mouth at a rate comparable with the detachment rate of relatively hot and dense field-aligned plasma filaments, or 'blobs,' from the last closed flux surface. When the dynamic character of the scrape-off layer is taken into account, transient low density and low temperature states occur during which the Landau damping can be weak enough to allow the radiated spectrum to penetrate radially deep inward. When the lower hybrid wave intercepts a dense and hot 'blob' a few cm in front of the antenna, then strong damping of the high wave number components can occur. This is the scenario we propose for explaining the generation of fast electrons far away from the grill mouth.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BL - Fyzika plasmatu a výboje v plynech

OECD FORD obor

—

Projekt

<a href="/cs/project/LM2011021" target="_blank" >LM2011021: COMPASS-RI - příspěvek na provoz a základní personální zajištění tokamaku COMPASS - velké výzkumné infrastruktury celoevropského významu</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

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

56

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

AT - Rakouská republika

Počet stran výsledku

21

Strana od-do

036004

Kód UT WoS článku

000373378200005

EID výsledku v databázi Scopus

2-s2.0-84960404729