Electromagnetic characteristics of geodesic acoustic mode in the COMPASS tokamak

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F17%3A00480872" target="_blank" >RIV/61389021:_____/17:00480872 - isvavai.cz</a>

Alternative codes found

RIV/68407700:21340/17:00319364 RIV/00216208:11320/17:10371492

Result on the web

<a href="http://dx.doi.org/10.1088/1741-4326/aa897e" target="_blank" >http://dx.doi.org/10.1088/1741-4326/aa897e</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1741-4326/aa897e" target="_blank" >10.1088/1741-4326/aa897e</a>

Result language

angličtina

Original language name

Electromagnetic characteristics of geodesic acoustic mode in the COMPASS tokamak

Original language description

Axisymmetric geodesic acoustic mode (GAM) oscillations of the magnetic field, plasma potential and electron temperature have been identified on the COMPASS tokamak. This work brings an overview of their electromagnetic properties studied by multi-pin reciprocating probes and magnetic diagnostics. The n = 0 fluctuations form a continuous spectrum in limited plasmas but change to a single dominant peak in diverted configuration. At the edge of diverted plasmas the mode exhibits a non-local structure with a constant frequency over a radial extent of at least several centimeters. Nevertheless, the frequency still reacts on temporal changes of plasma temperaturencaused by an auxiliary NBI heating as well as those induced by periodic sawtooth crashes. Radial wavelength of the mode is found to be about 1–4 cm, with values larger for the plasma potential than for the electron temperature. The mode propagates radially outward and its radial structure induces oscillations of a poloidal E × B velocity, that can locally reach the level of the mean poloidal flow. Bicoherence analysis confirms a non-linear interaction of GAM with a broadband ambient turbulence. The mode exhibits strong axisymmetric magnetic oscillations that are studied both in the poloidal and radial components of the magnetic field. Their poloidal standing-wave structure was confirmed and described for the first time in diverted plasmas. In limited plasmas their amplitude scales with safety factor. Strong suppression of the magnetic GAM component, and possibly of GAM itself, is observed during co-current but not counter-current NBI.

Czech name

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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

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OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

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

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Volume of the periodical

57

Issue of the periodical within the volume

12

Country of publishing house

AT - AUSTRIA

Number of pages

15

Pages from-to

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UT code for WoS article

000413136900002

EID of the result in the Scopus database

2-s2.0-85034417019