Impurity transport measurements in beam heated low-confinement mode discharges in the National Spherical Torus Experiment
Impurity transport measurements in beam heated low-confinement mode discharges in the National Spherical Torus Experiment
复制标题
国家球形环面实验中束加热低约束模式放电中的杂质输运测量
DOI：
10.1063/1.1610473
复制
发表时间：
2003
影响因子：
2.2
通讯作者：
C. Bourdelle
中科院分区：
文献类型：
--
作者：
D. Stutman;M. Finkenthal;R. Bell;S. Kaye;B. LeBlanc;J. Menard;E. Synakowski;D. Darrow;V. Soukhanovskii;C. Bourdelle
杂质注入实验在国家球面环面实验中进行[NSTX， M. Ono et al., nuclear]。聚变40,557(2000)]在低场、低纵横比装置中首次评估低z杂质输运。在光束加热、同向旋转l模式（低约束）放电中注入短氖泡，用过滤超软x射线二极管阵列监测了连续氖电荷态的径向穿透。在几个光谱波段的氖发射率的时间相关模型表明，在这些强旋转等离子体中，核心扩散系数在新古典范围内（<1 m2/s），与从功率平衡分析推断的低热离子输运一致。相比之下，由于NSTX的Larmor半径较大，如果假设类似托卡马克的不稳定增长率，湍流扩散将达到数十m2/s。低得多的实验扩散率表明，湍流离子输运在NSTX核心中一定受到了很大程度的抑制。它不是……
Impurity injection experiments were performed in the National Spherical Torus Experiment [NSTX, M. Ono et al., Nucl. Fusion 40, 557 (2000)] for a first assessment of low-Z impurity transport in a low field, low-aspect ratio device. Short neon puffs were injected in beam heated, co-rotating L-mode (low confinement) discharges and the radial penetration of the successive neon charge states has been monitored with arrays of filtered ultrasoft x-ray diodes. Time-dependent modeling of the neon emissivity in several spectral bands indicates a core diffusion coefficient in the neoclassical range (<1 m2/s) in these strongly rotating plasmas, consistent with the low thermal ion transport inferred from the power balance analysis. By contrast, due to the large Larmor radii in NSTX turbulent diffusion would reach tens of m2/s if tokamak-like instability growth rates were assumed. The much lower experimental diffusivity then suggests that turbulent ion transport must be largely suppressed in the NSTX core. It is not y...