Impact of toroidal and poloidal mode spectra on the control of non-axisymmetric fields in tokamaks
العنوان: | Impact of toroidal and poloidal mode spectra on the control of non-axisymmetric fields in tokamaks |
---|---|
المؤلفون: | Lanctot, Matthew J., Park, J. -K., Piovesan, Paolo, Sun, Y., Buttery, Richard J., Frassinetti, L., Grierson, Brian A., Hanson, Jeremy M., Haskey, Shaun R., In, Y., Jeon, Y. M., La Haye, Robert J., Logan, N. C., Marrelli, L., Orlov, Dmitry M., Paz-Soldan, Carlos, Wang, H. H., Strait, Edward J. |
سنة النشر: | 2021 |
المجموعة: | SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
مصطلحات موضوعية: | 70 PLASMA PHYSICS AND FUSION TECHNOLOGY |
الوصف: | In several tokamaks, non-axisymmetric magnetic field studies show that applied magnetic fields with a toroidal harmonic n = 2 can lead to disruptive n = 1 locked modes. In Ohmic plasmas, n = 2 magnetic reconnection thresholds in otherwise stable discharges are readily accessed at edge safety factors q ~ 3, low density, and low rotation. Similar to previous studies with n = 1 fields, the thresholds are correlated with the “overlap” field computed with the IPEC code. The overlap field quantifies the plasma-mediated coupling of the external field to the resonant field. Remarkably, the “critical overlap fields” at which magnetic islands form are similar for applied n =1 and 2 fields. The critical overlap field increases with plasma density and edge safety factor but is independent of the toroidal field. Poloidal harmonics m > nq dominate the drive for resonant fields while m < nq harmonics have a negligible impact. This contrasts with previous results in H-mode discharges at high plasma pressure in which the toroidal angular momentum is sensitive to low poloidal harmonics. Altogether, these results highlight unique requirements for n > 1 field control including the need for multiple rows of coils to control selected plasma parameters for specific functions (e.g., rotation control or ELM suppression). |
نوع الوثيقة: | other/unknown material |
وصف الملف: | application/pdf |
اللغة: | unknown |
Relation: | http://www.osti.gov/servlets/purl/1373416; https://www.osti.gov/biblio/1373416; https://doi.org/10.1063/1.4982688 |
DOI: | 10.1063/1.4982688 |
الاتاحة: | http://www.osti.gov/servlets/purl/1373416 https://www.osti.gov/biblio/1373416 https://doi.org/10.1063/1.4982688 |
رقم الانضمام: | edsbas.DBBDE039 |
قاعدة البيانات: | BASE |
DOI: | 10.1063/1.4982688 |
---|