Study of secondary instability of precursor magnetic island in COMPASS density limit disruptions

0531034 - ÚFP 2021 RIV US eng J - Journal Article
Salzedas, F. - Shah, S. I.W. - Havlíček, Josef - Stöckel, Jan - Háček, Pavel - Varju, Jozef - Havránek, Aleš - Pánek, Radomír - Silva, C.
Study of secondary instability of precursor magnetic island in COMPASS density limit disruptions.
Physics of Plasmas. Roč. 27, č. 2 (2020), č. článku 022515. ISSN 1070-664X. E-ISSN 1089-7674
R&D Projects: GA MŠMT(CZ) LM2015045; GA MŠMT(CZ) EF16_019/0000768
Institutional support: RVO:61389021
Keywords : COMPASS * magnetic island
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 2.023, year: 2020
Method of publishing: Open access
https://aip.scitation.org/doi/10.1063/1.5123677

A systematic study of COMPASS density limit disruptions (DLDs) was carried out to analyze the relation between the precursor magnetic island and its secondary instability (SI). In all of these plasmas, the SI was always found present at the onset of energy confinement erosion. The duration of this erosion was shorter for precursor quasi-locked island than for rotating island, and the larger the island amplitude, the shorter the duration. It was also found, at the onset of the erosion of energy confinement, an inverse relation between the magnetic island amplitude and its rotation frequency, showing that erosion can start at different values of precursor island amplitude, depending on what is its rotation frequency. DLDs occur either with smaller precursor island rotating faster or larger island rotating slower (quasi-locked).
Permanent Link: http://hdl.handle.net/11104/0309796