Effect of finite beta on neoclassical transport characteristics in CFQS quasi-axisymmetric stellarator
CFQS is the world’s first modular-coil-type quasi-axisymmetric stellarator, which is currently under construction. This study systematically investigates the effect of finite beta (volume-averaged beta, 〈 β 〉) on the neoclassical transport characteristics of CFQS plasmas. An intensification of the f...
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IOP Publishing
2025-01-01
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| Series: | Journal of Physics Communications |
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| Online Access: | https://doi.org/10.1088/2399-6528/adf02d |
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| author | Yang Lang Mitsutaka Isobe Akihiro Shimizu Hiroyuki Yamaguchi Kunihiro Ogawa Haifeng Liu Yuhong Xu |
| author_facet | Yang Lang Mitsutaka Isobe Akihiro Shimizu Hiroyuki Yamaguchi Kunihiro Ogawa Haifeng Liu Yuhong Xu |
| author_sort | Yang Lang |
| collection | DOAJ |
| description | CFQS is the world’s first modular-coil-type quasi-axisymmetric stellarator, which is currently under construction. This study systematically investigates the effect of finite beta (volume-averaged beta, 〈 β 〉) on the neoclassical transport characteristics of CFQS plasmas. An intensification of the finite- β effect increases the neoclassical bootstrap current and amplifies variations in the major helical ripple component B _1,1 and other non-axisymmetric magnetic components. During this process, the magnetic flux surfaces essentially remain at moderate β values (〈 β 〉 = 0.77%); however, at high β values (〈 β 〉 = 2.03%), the flux surface becomes significantly deformed due to intensified axisymmetry breaking. The neoclassical diffusion properties in the CFQS are investigated for different finite β values using the independently developed Monte Carlo Neoclassical Transport Simulation code. The charged-particle fluxes are estimated as functions of the radial electric field. Subsequently, the neoclassical diffusion coefficients and plasma parameters at moderate β (〈 β 〉 = 0.77%) and high β (〈 β 〉 = 2.03%) values are examined under ambipolar conditions. Electron roots are observed to provide strong confinement in the CFQS at various finite β values. |
| format | Article |
| id | doaj-art-e6bbb27f24db4aeeb661303574df6d52 |
| institution | DOAJ |
| issn | 2399-6528 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| spelling | doaj-art-e6bbb27f24db4aeeb661303574df6d522025-08-20T03:14:06ZengIOP PublishingJournal of Physics Communications2399-65282025-01-019707500410.1088/2399-6528/adf02dEffect of finite beta on neoclassical transport characteristics in CFQS quasi-axisymmetric stellaratorYang Lang0https://orcid.org/0000-0003-0824-3448Mitsutaka Isobe1Akihiro Shimizu2https://orcid.org/0000-0003-3764-3184Hiroyuki Yamaguchi3https://orcid.org/0000-0002-1177-3370Kunihiro Ogawa4https://orcid.org/0000-0003-4555-1837Haifeng Liu5https://orcid.org/0000-0002-0424-645XYuhong Xu6https://orcid.org/0000-0003-4882-647XThe Graduate University for Advanced Studies , SOKENDAI, Toki, JapanThe Graduate University for Advanced Studies , SOKENDAI, Toki, Japan; National Institute for Fusion Science , National Institutes of Natural Sciences, Toki, Japan; Mahasarakham University , Maha Sarakham, ThailandThe Graduate University for Advanced Studies , SOKENDAI, Toki, Japan; National Institute for Fusion Science , National Institutes of Natural Sciences, Toki, JapanThe Graduate University for Advanced Studies , SOKENDAI, Toki, Japan; National Institute for Fusion Science , National Institutes of Natural Sciences, Toki, JapanThe Graduate University for Advanced Studies , SOKENDAI, Toki, Japan; National Institute for Fusion Science , National Institutes of Natural Sciences, Toki, JapanInstitute of Fusion Science, School of Physical Science and Technology, Southwest Jiaotong University , Chengdu, People’s Republic of ChinaInstitute of Fusion Science, School of Physical Science and Technology, Southwest Jiaotong University , Chengdu, People’s Republic of ChinaCFQS is the world’s first modular-coil-type quasi-axisymmetric stellarator, which is currently under construction. This study systematically investigates the effect of finite beta (volume-averaged beta, 〈 β 〉) on the neoclassical transport characteristics of CFQS plasmas. An intensification of the finite- β effect increases the neoclassical bootstrap current and amplifies variations in the major helical ripple component B _1,1 and other non-axisymmetric magnetic components. During this process, the magnetic flux surfaces essentially remain at moderate β values (〈 β 〉 = 0.77%); however, at high β values (〈 β 〉 = 2.03%), the flux surface becomes significantly deformed due to intensified axisymmetry breaking. The neoclassical diffusion properties in the CFQS are investigated for different finite β values using the independently developed Monte Carlo Neoclassical Transport Simulation code. The charged-particle fluxes are estimated as functions of the radial electric field. Subsequently, the neoclassical diffusion coefficients and plasma parameters at moderate β (〈 β 〉 = 0.77%) and high β (〈 β 〉 = 2.03%) values are examined under ambipolar conditions. Electron roots are observed to provide strong confinement in the CFQS at various finite β values.https://doi.org/10.1088/2399-6528/adf02dfinite betaaxisymmetry breakingneoclassical transportMonte Carlo methodCFQSambipolar radial electric field |
| spellingShingle | Yang Lang Mitsutaka Isobe Akihiro Shimizu Hiroyuki Yamaguchi Kunihiro Ogawa Haifeng Liu Yuhong Xu Effect of finite beta on neoclassical transport characteristics in CFQS quasi-axisymmetric stellarator Journal of Physics Communications finite beta axisymmetry breaking neoclassical transport Monte Carlo method CFQS ambipolar radial electric field |
| title | Effect of finite beta on neoclassical transport characteristics in CFQS quasi-axisymmetric stellarator |
| title_full | Effect of finite beta on neoclassical transport characteristics in CFQS quasi-axisymmetric stellarator |
| title_fullStr | Effect of finite beta on neoclassical transport characteristics in CFQS quasi-axisymmetric stellarator |
| title_full_unstemmed | Effect of finite beta on neoclassical transport characteristics in CFQS quasi-axisymmetric stellarator |
| title_short | Effect of finite beta on neoclassical transport characteristics in CFQS quasi-axisymmetric stellarator |
| title_sort | effect of finite beta on neoclassical transport characteristics in cfqs quasi axisymmetric stellarator |
| topic | finite beta axisymmetry breaking neoclassical transport Monte Carlo method CFQS ambipolar radial electric field |
| url | https://doi.org/10.1088/2399-6528/adf02d |
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