Podestà M, Heidbrink W W, Bell R E, Feder R
Department of Physics and Astronomy, University of California Irvine, California 92697, USA.
Rev Sci Instrum. 2008 Oct;79(10):10E521. doi: 10.1063/1.2956744.
A new diagnostic, aimed at energy-resolved measurements of the spatial and temporal dynamics of fast ions in NSTX plasmas, is described. It is based on active charge-exchange recombination spectroscopy. The fast-ion signal is inferred from light emitted in the wavelength range of the D(alpha) line by fast ions recombining with an injected neutral beam. Two complementary systems are operational. The first system, based on a spectrometer coupled to a charge coupled device detector, has 16 channels with space, time, and energy resolution of 5 cm, 10 ms, and 10 keV, respectively. The second system monitors the energy-integrated fast-ion signal on time scales of approximately 20 micros at three different radii. Signals are measured by a multianode photomultiplier tube. For both systems, each channel includes two paired views, intercepting and missing the neutral beam for a direct subtraction of the background signal not associated with fast ions. Examples of signals from the 2008 NSTX run are presented.
本文描述了一种新的诊断方法，旨在对国家球形环面实验（NSTX）等离子体中快离子的空间和时间动态进行能量分辨测量。它基于主动电荷交换复合光谱技术。快离子信号是通过快离子与注入的中性束复合时在D（α）线波长范围内发射的光推断出来的。有两个互补的系统在运行。第一个系统基于一台与电荷耦合器件探测器相连的光谱仪，有16个通道，空间、时间和能量分辨率分别为5厘米、10毫秒和10千电子伏特。第二个系统在三个不同半径处监测大约20微秒时间尺度上的能量积分快离子信号。信号由多阳极光电倍增管测量。对于这两个系统，每个通道都包括两个配对视图，一个拦截中性束，另一个错过中性束，以便直接减去与快离子无关的背景信号。文中给出了2008年NSTX实验运行的信号示例。
