在DIII-D装置上利用电荷交换复合光谱法测量H模陡峭梯度区域的氘密度分布。

Measurement of deuterium density profiles in the H-mode steep gradient region using charge exchange recombination spectroscopy on DIII-D.

作者信息

Haskey S R, Grierson B A, Burrell K H, Chrystal C, Groebner R J, Kaplan D H, Pablant N A, Stagner L

机构信息

Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543-0451, USA.

General Atomics, P.O. Box 85608, San Diego, California 92186, USA.

出版信息

Rev Sci Instrum. 2016 Nov;87(11):11E553. doi: 10.1063/1.4963148.

DOI:10.1063/1.4963148

PMID:27910328

Abstract

Recent completion of a thirty two channel main-ion (deuterium) charge exchange recombination spectroscopy (CER) diagnostic on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] enables detailed comparisons between impurity and main-ion temperature, density, and toroidal rotation. In a H-mode DIII-D discharge, these new measurement capabilities are used to provide the deuterium density profile, demonstrate the importance of profile alignment between Thomson scattering and CER diagnostics, and aid in determining the electron temperature at the separatrix. Sixteen sightlines cover the core of the plasma and another sixteen are densely packed towards the plasma edge, providing high resolution measurements across the pedestal and steep gradient region in H-mode plasmas. Extracting useful physical quantities such as deuterium density is challenging due to multiple photoemission processes. These challenges are overcome using a detailed fitting model and by forward modeling the photoemission using the FIDASIM code, which implements a comprehensive collisional radiative model.

摘要

最近在DIII-D托卡马克装置上完成了一个32通道的主离子（氘）电荷交换复合光谱（CER）诊断[J. L. Luxon，《核聚变》42, 614 (2002)]，这使得能够对杂质与主离子的温度、密度以及环向旋转进行详细比较。在H模DIII-D放电中，这些新的测量能力被用于提供氘密度分布，证明汤姆逊散射与CER诊断之间分布对齐的重要性，并有助于确定磁分界面处的电子温度。16条视线覆盖等离子体核心，另外16条则密集地朝向等离子体边缘排列，从而在H模等离子体的基座和陡峭梯度区域提供高分辨率测量。由于多种光发射过程，提取诸如氘密度等有用物理量具有挑战性。通过使用详细的拟合模型以及利用实现了综合碰撞辐射模型的FIDASIM代码对光发射进行正向建模，克服了这些挑战。