McKee G R, Fonck R J, Shafer M W, Uzun-Kaymak I U, Yan Z
University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Rev Sci Instrum. 2010 Oct;81(10):10D741. doi: 10.1063/1.3495788.
Imaging of the size, shape, time-averaged, and time-resolved dynamics of long-wavelength density turbulence structures is accomplished with an expanded, high-sensitivity, wide-field beam emission spectroscopy (BES) diagnostic on DIII-D. A 64-channel BES system is configured with an 8×8 grid of discrete channels that image an approximately 7×9 cm region at the outboard midplane. The grid covers multiple correlation lengths and each channel shape matches the measured radial-poloidal correlation length asymmetry of turbulent eddies. The wide field 8×8 imaging capability allows for sampling of essentially the full two-dimensional spatial correlation function for typical plasma conditions. The sampled area can be radially scanned over 0.4<r/a<1, including the core (ñ/n<1%), pedestal, and scrape-off-layer. The resulting time-resolved visualizations of turbulence and flows provide critical data on turbulence dynamics.
利用DIII-D上扩展的、高灵敏度、宽视场束发射光谱（BES）诊断技术，对长波长密度湍流结构的大小、形状、时间平均和时间分辨动力学进行成像。一个64通道的BES系统配置为8×8的离散通道网格，可对外侧中平面约7×9厘米的区域进行成像。该网格覆盖多个相关长度，每个通道形状与湍流涡旋测量的径向-极向相关长度不对称性相匹配。8×8的宽视场成像能力允许在典型等离子体条件下对基本完整的二维空间相关函数进行采样。采样区域可以在0.4<r/a<1范围内进行径向扫描，包括核心区（ñ/n<1%）、台基和刮离层。由此得到的湍流和流场的时间分辨可视化提供了关于湍流动力学的关键数据。
