CFQS 中离子温度梯度模的同位素效应研究

doi:10.16568/j.0254-6086.202403017

摘要/Abstract

摘要： 基于中国首台准环对称仿星器(CFQS)，利用回旋动理学弗拉索夫代码 GKV 率先开展准环对称仿星器中离子温度梯度模(ITG)的同位素效应研究。模拟结果表明，CFQS 中存在明显的 ITG 同位素效应，随着氢同位素质量的增加，ITG 的增长率显著下降。通过扫描等离子参数，如不同氢同位素混合的比例、密度梯度以及离子与电子温度比，研究了这些等离子体参数下 CFQS 中同位素效应的变化。此外，在不同的环向或径向位置处研究了 CFQS 的三维磁场位形对 ITG 同位素的影响，发现 ITG 的同位素效应在不同的环向和径向位置均普遍存在。

关键词: 同位素效应；离子温度梯度模；准环对称仿星器；CFQS

Abstract: Based on Chinese First Quasi-axisymmetric Stellarator (CFQS), we carry out the study of isotope effect on ion temperature gradient (ITG) mode in quasi-axisymmetric stellarator by using the gyrokinetic Vlasov simulation code GKV. The simulation results show that there is an obvious isotope effect on ITG in CFQS. The growth rate of ITG decreases significantly with the increase of the mass of hydrogen isotope. To scan the plasma parameters in CFQS, such as the content of the heavier hydrogen isotope in the mixed plasma, density gradient, and ion-to-electron temperature ratio, we study impact of these parameters on isotope effect. Otherwise, we also study the isotope effect of ITG in different toroidal angles and different radial positions of CFQS, and the results reveal the isotope effect of ITG is universal in CFQS.

Key words: Isotope effect, Ion temperature gradient mode, Quasi-axisymmetric stellarator, CFQS

中图分类号:

TL61+ 2

覃程, 黄捷, 李沫杉. CFQS 中离子温度梯度模的同位素效应研究 [J]. 核工业西南物理研究院, 2024, 44(3): 359-366.

QIN Cheng, HUANG Jie, LI Mo-shan . The isotope effect on ion temperature gradient mode in CFQS[J]. Nuclear Fusion and Plasma Physics, 2024, 44(3): 359-366.

参考文献

[1] Yushmanov P N, Takizuka T, Riedel K S, et al. Scalings for tokamak energy confinement [J]. Nuclear Fusion, 1990, 30(10): 1999.

[2] ITER E D A. Plasma confinement and transport [J]. Nuclear Fusion, 1999, 39(12): 2175.

[3] Bessenrodt-Weberpals M, Wagner F, Gehre O, et al. The isotope effect in ASDEX [J]. Nuclear Fusion, 1993, 33(8): 1205.

[4] Liu B, Pedrosa M A, van Milligen B P, et al. Isotope effect physics, turbulence and long-range correlation studies in the TJ-II stellarator [J]. Nuclear Fusion, 2015, 55(11): 112002.

[5] Garcia J, Görler T, Jenko F, et al. Gyrokinetic nonlinear isotope effects in tokamak plasmas [J]. Nuclear Fusion, 2016, 57(1): 014007.

[6] Xu Y, Hidalgo C, Shesterikov I, et al. Isotope effect and multiscale physics in fusion plasmas [J]. Physical Review Letters, 2013, 110(26): 265005.

[7] Ida K, Yoshinuma M, Tanaka K, et al. Characteristics of plasma parameters and turbulence in the isotope-mixing and the non-mixing states in hydrogen–deuterium mixture plasmas in the large helical device [J]. Nuclear Fusion, 2020, 61(1): 016012.

[8] Losada U, Kobayashi T, Ohshima S, et al. Spatial characterization of edge zonal flows in the TJ-II stellarator: the roles of plasma heating and isotope mass [J]. Plasma Physics and Controlled Fusion, 2021, 63(4): 044002.

[9] Garbet X. Towards a full self-consistent numerical simulation of tokamak plasma turbulence [J]. Plasma Physics and Controlled Fusion, 1997, 39(12B): B91.

[10] Idomura Y. Isotope and plasma size scaling in ion temperature gradient driven turbulence [J]. Physics of Plasmas, 2019, 26(12): 120703.

[11] Tanaka K, Nakata M, Ohtani Y, et al. Extended investigations of isotope effects on ECRH plasma in LHD [J]. Plasma Physics and Controlled Fusion, 2019, 62(2): 024006.

[12] Bonanomi N, Angioni C, Crandall P C, et al. Effect of the isotope mass on the turbulent transport at the edge of L-mode plasmas in ASDEX Upgrade and JET-ILW [J]. Nuclear Fusion, 2019, 59(12): 126025.

[13] Bourdelle C, Camenen Y, Citrin J, et al. Fast H isotope and impurity mixing in ion-temperature-gradient turbulence [J]. Nuclear Fusion, 2018, 58(7): 076028.

[14] Tokar M Z, Kalupin D, Unterberg B. Nature of the isotope effect on transport in tokamaks [J]. Physical Review Letters, 2004, 92(21): 215001.

[15] Stroth U. A comparative study of transport in stellarators and tokamaks [J]. Plasma Physics and Controlled Fusion, 1998, 40(1): 9.

[16] Osakabe M, Isobe M, Tanaka M, et al. Preparation and commissioning for the LHD deuterium experiment [J]. IEEE Transactions on Plasma Science, 2018, 46(6): 2324.

[17] Nakata M, Nunami M, Sugama H, et al. Impact of hydrogen isotope species on microinstabilities in helical plasmas [J]. Plasma Physics and Controlled Fusion, 2016, 58(7): 074008.

[18] Nakata M, Nunami M, Sugama H, et al. Isotope effects on trapped-electron-mode driven turbulence and zonal flows in helical and tokamak plasmas [J]. Physical Review Letters, 2017, 118(16): 165002.

[19] Alcusón J A, Xanthopoulos P, Plunk G G, et al. Suppression of electrostatic micro-instabilities in maximum-J stellarators [J]. Plasma Physics and Controlled Fusion, 2020, 62(3): 035005.

[20] He Y, Cheng J, Xu Y, et al. Impact of the mass isotope on plasma confinement and transport properties in the HL-2A tokamak [J]. Plasma Science and Technology, 2022, 24(9): 095102.

[21] Okamura S, Matsuoka K, Nishimura S, et al. Physics and engineering design of the low aspect ratio quasi-axisymmetric stellarator CHS-qa [J]. Nuclear Fusion, 2001, 41(12): 1865.

[22] Shimizu A, Liu H, Isobe M, et al. Configuration property of the Chinese first quasi-axisymmetric stellarator [J]. Plasma and Fusion Research, 2018, 13: 3403123.

[23] Isobe M, Shimizu A, Liu H, et al. Current status of NIFS-SWJTU joint project for quasi-axisymmetric stellarator CFQS [J]. Plasma and Fusion Research, 2019, 14: 3402074.

[24] Liu H, Shimizu A, Xu Y, et al. Configuration characteristics of the Chinese first quasi-axisymmetric stellarator [J]. Nuclear Fusion, 2020, 61(1): 016014.

[25] Wang X Q, Xu Y, Shimizu A, et al. The threedimensional equilibrium with magnetic islands and MHD instabilities in the CFQS quasi-axisymmetric stellarator [J]. Nuclear Fusion, 2021, 61(3): 036021.

[26] Watanabe T H, Sugama H. Velocity-space structures of distribution function in toroidal ion temperature gradient turbulence [J]. Nuclear Fusion, 2006, 46(1): 24.

[27] Frieman E A, Chen L. Nonlinear gyrokinetic equations for low‐frequency electromagnetic waves in general plasma equilibria [J]. The Physics of Fluids, 1982, 25(3): 502.

[28] Brizard A J, Hahm T S. Foundations of nonlinear gyrokinetic theory [J]. Reviews of Modern Physics, 2007, 79(2): 421.

[29] Antonsen Jr T M, Lane B. Kinetic equations for low frequency instabilities in inhomogeneous plasmas [J]. Physics of Fluids, 1980, 23(6): 1205.

[30] Nakata M, Honda M, Yoshida M, et al. Validation studies of gyrokinetic ITG and TEM turbulence simulations in a JT-60U tokamak using multiple flux matching [J]. Nuclear Fusion, 2016, 56(8): 086010.

[31] Beer M A, Cowley S C, Hammett G W. Field-aligned coordinates for nonlinear simulations of tokamak turbulence [J]. Physics of Plasmas, 1995, 2(7): 2687.

[32] Huang J, Nakata M, Xu Y, et al. Identification of electrostatic microinstability maps in quasi-axisymmetric stellarator [J]. Physics of Plasmas, 2022, 29(5): 052505.

[33] Urano H, Narita E. Review of hydrogen isotope effects on H-mode confinement in JT-60U [J]. Plasma Physics and Controlled Fusion, 2021, 63(8): 084003.

[34] Schneider P A, Bonanomi N, Angioni C, et al. Fast-ion pressure dominating the mass dependence of the core heat transport in ASDEX Upgrade H-modes [J]. Nuclear Fusion, 2021, 61(3): 036033.

[35] 黄捷, 李沫杉, 覃程, 等. 中国首台准环对称仿星器中离子温度梯度模的模拟研究 [J]. 物理学报, 2022, 71(18): 213.

[36] Nakata M, Nagaoka K, Tanaka K, et al. Gyrokinetic microinstability analysis of high-Ti and high-Te isotope plasmas in Large Helical Device [J]. Plasma Physics and Controlled Fusion, 2018, 61(1): 014016.

[37] Montroll E W, Weiss G H. Random walks on lattices. II [J]. Journal of Mathematical Physics, 1965, 6(2): 167.

[38] Balescu R. Anomalous transport in turbulent plasmas and continuous time random walks [J]. Physical Review E, 1995, 51(5): 4807.

[39] Nakata M, Matsuyama A, Aiba N, et al. Local gyrokinetic Vlasov simulations with realistic tokamak MHD equilibria [J]. Plasma and Fusion Research, 2014, 9: 1403029.

[40] Liu H, Shimizu A, Isobe M, et al. Magnetic configuration and modular coil design for the Chinese first quasi-axisymmetric stellarator [J]. Plasma and Fusion Research, 2018, 13: 3405067.