Microstability of β ~ 1 tokamak equilibria
| dc.contributor.author | Gaur, Rahul | |
| dc.contributor.author | Abel, Ian G. | |
| dc.contributor.author | Dickinson, David | |
| dc.contributor.author | Dorland, William D. | |
| dc.date.accessioned | 2023-09-19T16:01:51Z | |
| dc.date.available | 2023-09-19T16:01:51Z | |
| dc.date.issued | 2023-03-01 | |
| dc.description.abstract | High-power-density tokamaks offer a potential solution to design cost-effective fusion devices. One way to achieve high power density is to operate at a high β value (the ratio of thermal to magnetic pressure), i.e. β∼1. However, a β∼1 state may be unstable to various pressure- and current-driven instabilities or have unfavourable microstability properties. To explore these possibilities, we generate β∼1 equilibria and investigate their stability. First, we demonstrate the generation of high- β equilibria with the computer code VMEC. We then analyse these equilibria to determine their stability against the infinite- n ideal-ballooning mode. We follow that by engaging in a detailed microstability study using the GS2 code, beginning with assessments of electrostatic ion-temperature-gradient and trapped election mode instabilities. We observe interesting behaviour for the high- β equilibria – stabilization of these modes through two distinct mechanisms – large negative local shear and reversal of electron precession drift. Finally, we perform electromagnetic gyrokinetic simulations and observe enhanced stability in the outer core of high- β equilibria and absence of kinetic ballooning modes in the negative-triangularity, high- β equilibria. The enhanced outer-core stability of high- β equilibria is different from their lower- β counterparts and offers an alternative, potentially favourable regime of tokamak operation. | |
| dc.description.uri | https://doi.org/10.1017/S0022377823000107 | |
| dc.identifier | https://doi.org/10.13016/dspace/9t2z-2v3h | |
| dc.identifier.citation | Gaur, R., Abel, I., Dickinson, D., & Dorland, W. (2023). Microstability of β ~ 1 tokamak equilibria. Journal of Plasma Physics, 89(1), 905890112. | |
| dc.identifier.uri | http://hdl.handle.net/1903/30538 | |
| dc.language.iso | en_US | |
| dc.publisher | Cambridge University Press | |
| dc.relation.isAvailableAt | College of Computer, Mathematical & Natural Sciences | en_us |
| dc.relation.isAvailableAt | Physics | en_us |
| dc.relation.isAvailableAt | Digital Repository at the University of Maryland | en_us |
| dc.relation.isAvailableAt | University of Maryland (College Park, MD) | en_us |
| dc.subject | fusion plasma | |
| dc.subject | plasma simulation | |
| dc.subject | plasma instabilities | |
| dc.title | Microstability of β ~ 1 tokamak equilibria | |
| dc.type | Article | |
| local.equitableAccessSubmission | No |