Shafer M W, Battaglia D J, Unterberg E A, Evans T E, Hillis D L, Maingi R
Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Rev Sci Instrum. 2010 Oct;81(10):10E534. doi: 10.1063/1.3481166.
A new tangential two-dimensional soft x-ray imaging system (SXRIS) is being designed to examine the edge island structure in the lower X-point region of DIII-D. Plasma shielding and/or amplification of the calculated vacuum islands may play a role in the suppression of edge-localized modes via resonant magnetic perturbations (RMPs). The SXRIS is intended to improve the understanding of three-dimensional (3D) phenomena associated with RMPs. This system utilizes a tangential view with a pinhole imaging system and spectral filtering with beryllium foils. SXR emission is chosen to avoid line radiation and allows suitable signal at the top of a H-mode pedestal where T(e)∼1-2 keV. A synthetic diagnostic calculation based on 3D SXR emissivity estimates is used to help assess signal levels and resolution of the design. A signal-to-noise ratio of 10 at 1 cm resolution is expected for the perturbed signals, which are sufficient to resolve most of the predicted vacuum island sizes.
一种新型的切向二维软X射线成像系统（SXRIS）正在设计中，用于研究DIII-D装置下X点区域的边缘岛结构。等离子体屏蔽和/或计算出的真空岛放大可能在通过共振磁扰动（RMP）抑制边缘局域模中发挥作用。SXRIS旨在增进对与RMP相关的三维（3D）现象的理解。该系统采用针孔成像系统的切向视图和铍箔光谱滤波。选择SXR发射以避免线辐射，并在H模基座顶部获得合适的信号，此处电子温度T(e)约为1-2千电子伏特。基于3D SXR发射率估计的综合诊断计算用于帮助评估设计的信号水平和分辨率。预计扰动信号在1厘米分辨率下的信噪比为10，这足以分辨大多数预测的真空岛尺寸。
