Boedo J A, Crocker N, Chousal L, Hernandez R, Chalfant J, Kugel H, Roney P, Wertenbaker J
Department of Mechanical and Aerospace Engineering, Energy Research Center, University of California, San Diego, La Jolla, California 92093-0417, USA.
Rev Sci Instrum. 2009 Dec;80(12):123506. doi: 10.1063/1.3266065.
We describe a fast reciprocating Langmuir probe and drive system, which has four main new features: (1) use of high-temperature, vacuum, circuit boards instead of cables to reduce weight and increase to 21 the number of possible connections, (2) rotatable and removable shaft, (3) 10 tip construction with designed hardware bandwidth up to 10 MHz, and (4) a detachable and modular tip assembly for easy maintenance. The probe is mounted in a fast pneumatic drive capable of speeds approximately 7 m/s and approximately 20g's acceleration in order to reach the scrape-off layer (SOL) and pedestal regions and remain inserted long enough to obtain good statistics while minimizing the heat deposition to the tips and head in a power density environment of 1-10 MW/m2. The National Spherical Torus Experiment SOL features electron temperature, T(e) approximately 10-30 eV, and electron density, n(e) approximately 0.1-5x10(12) cm(-3) while the pedestal features n(e) approximately 0.5-1.5x10(13) cm(-3) and T(e) approximately 30-150 eV. The probe described here has ten tips which obtain a wide spectrum of plasma parameters: electron temperature profile T(e)(r), electron density profile n(e)(r) and Mach number profile M(r), floating potential V(f)(r), poloidal and radial electric field profiles E(theta)(r) and E(rho)(r), saturation current profile I(sat)(r), and their fluctuations up to 3 MHz. We describe the probe and show representative radial profiles of various parameters.
我们描述了一种快速往复式朗缪尔探针及驱动系统，它具有四个主要新特性：（1）使用高温、真空电路板而非电缆，以减轻重量并将可能的连接数量增加到21个；（2）可旋转和可拆卸的轴；（3）具有设计硬件带宽高达10 MHz的10个尖端结构；（4）可拆卸的模块化尖端组件，便于维护。该探针安装在一个快速气动驱动器中，能够达到约7 m/s的速度和约20g的加速度，以便到达刮离层（SOL）和基座区域，并保持插入足够长的时间以获得良好的统计数据，同时在1 - 10 MW/m²的功率密度环境中，将热量沉积到尖端和头部的量降至最低。国家球形环面实验的SOL特征为电子温度T(e)约为10 - 30 eV，电子密度n(e)约为0.1 - 5×10(12) cm(-3)，而基座的特征为n(e)约为0.5 - 1.5×10(13) cm(-3)，T(e)约为30 - 150 eV。这里描述的探针有十个尖端，可获取广泛的等离子体参数：电子温度分布T(e)(r)、电子密度分布n(e)(r)和马赫数分布M(r)、浮动电位V(f)(r)、极向和径向电场分布E(theta)(r)和E(rho)(r)、饱和电流分布I(sat)(r)，以及高达3 MHz的波动。我们描述了该探针并展示了各种参数的代表性径向分布。
