Agostini M, Scarin P, Cavazzana R, Fassina A, Alfier A, Cervaro V
Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, 35127 Padova, Italy.
Rev Sci Instrum. 2010 Oct;81(10):10D715. doi: 10.1063/1.3478679.
The edge of the reversed field pinch experiment RFX-mod (R=2 m, a=0.46 m) is characterized by a complex magnetic topology and strong pressure gradients. A set of fast spectroscopic diagnostics has been designed to characterize both main plasma edge parameters and turbulence, including coherent structures (blobs) and radial profiles of the thermodynamic variables. Measurements of the edge radial profiles of electron density (n(e)), temperature (T(e)), and pressure (P(e)) are obtained by a thermal helium beam diagnostic, which locally measures the ratios of the spectral lines emitted by a neutral He cloud puffed into hydrogen plasma discharges. A gas puff imaging system allows the high frequency (1 MHz bandwidth) measurement of the fluctuations of He I emissivity in the same positions. The system measures both the intermittent behavior of the edge turbulence and n(e), T(e), and P(e) profiles of the corresponding coherent structures, with a resolution down to 6 μs. The optical diagnostics are complemented by a set of triaxial magnetic coils to simultaneously characterize the edge magnetic field.
反场箍缩实验装置RFX-mod（R = 2米，a = 0.46米）的边缘具有复杂的磁拓扑结构和强压力梯度。设计了一套快速光谱诊断设备，用于表征主要的等离子体边缘参数和湍流，包括相干结构（团块）以及热力学变量的径向分布。通过热氦束诊断获得边缘电子密度（n(e)）、温度（T(e)）和压力（P(e)）的径向分布测量结果，该诊断方法局部测量注入氢等离子体放电中的中性氦云发射的谱线比率。气体喷注成像系统能够在相同位置对He I发射率的波动进行高频（1兆赫带宽）测量。该系统可测量边缘湍流的间歇性行为以及相应相干结构的n(e)、T(e)和P(e)分布，分辨率低至6微秒。光学诊断由一组三轴磁线圈补充，以同时表征边缘磁场。
