Speaker
Description
During vertical displacement events (VDEs) plasma column hits the wall and scrape-off layer (``halo'') currents can reach significant amplitudes [1]. Therefore, the related electromagnetic loads on plasma facing components (PFCs) should be thoroughly evaluated to guarantee their structural integrity. Modelling of halo currents for next generation tokamaks is a challenging task. For example, non-linear (3D plasma + 2D wall) MHD codes, like JOREK [2, 3], M3D [4], M3D-C1 [2, 5] and NIMROD [2, 6] are appropriate for study of the disruption physics, but might be too demanding in case one needs to analyse many scenarios and geometry configurations. Disruption-oriented (2D plasma + 3D wall) numerical tool CarMa0NL [7, 8] is more practical for design purposes, but it requires some physical insight for definition of the halo width $w_h(t)$. Such criteria is found here empirically by comparing magnetic measurements during COMPASS VDEs [3] with results of CarMa0NL modelling for a wide range of parameters.
It is shown that the halo width correlates with the value of safety factor on the last closed flux surface $q_\lambda(t)$. The best fit with experiment is obtained for $q_\lambda(t) \approx 1$, which suggests that m/n=1/1 kink instability might play a role in defining $w_h(t)$. Further, we discuss application of the findings to design of COMPASS-U tokamak [9].
References
[1] Strait E, Lao L, Luxon J and Reis E 1991 Nucl. Fusion 31 527
[2] Artola F J, Sovinec C R, Jardin S C, Hoelzl M, Krebs I and Clauser C 2021 Phys. Plasmas 28 052511
[3] Artola F J et al. 2021 Plasma Phys. Control. Fusion 63 064004
[4] Strauss H R, Paccagnella R and Breslau J 2010 Phys. Plasmas 17 082505
[5] Clauser C F, Jardin S C and Ferraro N M 2019 Nucl. Fusion 59 126037
[6] Bunkers K J and Sovinec C R 2020 Phys. Plasmas 27 112505
[7] Villone F, Barbato L, Mastrostefano S and Ventre S 2013 Plasma Phys. Controlled Fusion 55 095008
[8] Chen S L et al. 2019 Nucl. Fusion 59 106039
[9] Yanovskiy V V, Isernia N, Pustovitov V D, Scalera V, Villone F, Hromadka J, Imrisek M, Havlicek J, Hron M and Panek R 2021 Nucl. Fusion 61 096016
| Speaker's title | Mr |
|---|---|
| Speaker's email address | yanovskiy@ipp.cas.cz |
| Speaker's Affiliation | Institute of Plasma Physics of the CAS, Prague |
| Member State or IGO | Czech Republic |
