Perturbative analysis of low-frequency instabilities in high-field ST40 experiments
| العنوان: | Perturbative analysis of low-frequency instabilities in high-field ST40 experiments |
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| المؤلفون: | V.N. Duarte, N.N. Gorelenkov, S.M. Kaye, P.J. Bonofiglo, M. Podestà, J. Bland, P. Buxton, M. Gryaznevich, M. Romanelli, M. Sertoli |
| المصدر: | Nuclear Fusion. 63:036018 |
| بيانات النشر: | IOP Publishing, 2023. |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | Nuclear and High Energy Physics, Condensed Matter Physics |
| الوصف: | Linear and nonlinear perturbative analyses of low-frequency instabilities are presented for ST40 spherical torus high field plasmas, with simultaneous neutral beam heating due to two tangential sources at 25 keV and 55 keV. Initial plasma profiles on which the TRANSP and NUBEAM codes were based were obtained using an integrated analysis of several diagnostics including line-of-sight integrated and volume average measurements, as well as limited profile information from a charge-exchange-recombination spectrometer. Magnetohydrodynamics (MHD) analysis using the NOVA/NOVA-K codes suggests that the modes in the experiments are core-localized n = 1 eigenmodes with mixed acoustic and electromagnetic Alfvénic polarization. The global transport combined with the perturbative mode analysis indicates that there is greater tendency for bursty chirping response as the level of background micro-turbulence decreases in time and those predictions are shown to be consistent with the experimental data. This finding is interpreted in terms of the suppression of coherent phase-space structures that support chirping when the resonant fast ion dynamics is dominated by frequent stochastic, orbit-decorrelating events. |
| تدمد: | 1741-4326 0029-5515 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::2cddf28d5e958053d571300cc468840f https://doi.org/10.1088/1741-4326/acb5af |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi...........2cddf28d5e958053d571300cc468840f |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 17414326 00295515 |
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