EAST密度台基对线性剥离气球模稳定性的影响  

Effect of EAST density pedestal on linear peeling-ballooning mode stability

作　　者：刘志洋 王一丰 李永亮 张涛[1] 王敏锐 臧庆 刘海庆[1,2] 徐国盛 LIU Zhi-yang;WANG Yi-feng;LI Yong-liang;ZHANG Tao;WANG Min-rui;ZANG Qing;LIU Hai-qing;XU Guo-sheng(Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031;University of Science and Technology of China,Hefei 230026)

机构地区：[1]中国科学院合肥物质科学研究院等离子体物理研究所,合肥230031 [2]中国科学技术大学,合肥230026

出　　处：《核聚变与等离子体物理》2025年第1期69-75,共7页Nuclear Fusion and Plasma Physics

基　　金：国家磁约束核聚变能发展研究专项(2019YFE03030000,2022YFE03020004);国家自然科学基金青年科学基金(12005263)。

摘　　要：为了理解台基密度分布相关参数(分界面密度、台基顶部密度和归一化台基顶部碰撞率)对台基区线性剥离气球模稳定性的影响,基于EAST实验数据并利用ELITE程序进行了模拟研究。研究表明,随着分界面密度的降低(保持台基温度分布不变),台基从高环向模数主导的气球模边界附近逐渐移动到较低环向模数主导的剥离模边界附近,这主要是因为分界面密度降低,使压强梯度增加,离子逆磁频率增加,导致高环向模数的气球模更加稳定;随着台基顶部密度的降低(保持台基温度分布不变),台基从剥离气球模不稳定区域移动到稳定区;通过改变密度、温度来改变归一化台基顶部碰撞率,随着归一化台基顶部碰撞率的降低,台基从剥离气球模稳定区域移动到不稳定区。To understand the effects of parameters related to the pedestal density profile(separatrix density,pedestal top density and normalized pedestal top collisionality)on the stability of linear peeling-ballooning mode in the pedestal,the simulations have been performed with the ELITE code based on the EAST experimental data.The results show that with the decrease of separatrix density(the pedestal temperature profile is kept invariant),the pedestal gradually moves from near the ballooning mode boundary dominated by high-n mode to near the peeling mode boundary dominated by low-n mode,this is mainly because the decrease of the separatrix density,increases the pressure gradient,and the ion diamagnetic frequency,resulting in a more stable high-n ballooning mode.As the pedestal top density decreases(the pedestal temperature profile remains invariant),the pedestal moves from the unstable region of the peeling-ballooning mode to the stable one.The normalized pedestal top collisionality was adjusted by changing the density and temperature.Its decrease causes the pedestal moving from the stable region of the peeling-ballooning mode to the unstable one.

关 键 词：剥离气球模 分界面密度 台基顶部密度 归一化台基顶部碰撞率 

分 类 号：O5342[理学—等离子体物理]