Electric Field and Langmuir Probe Experiment

The FAST electric field instrument has ten sensors, two on each of the four 29 m radial wire booms (at 24 m and 29 m) and one on each of the two rigid 3 m axial booms. All except the four outermost sensors can also operate as current collecting Langmuir probes. Similar instruments were flown on S3-3, ISEE-1, CRRES, Polar and Cluster. The instrument is designed to provide the following: a vector measurement of the electric field from DC to about 20 kHz over a dynamic range of 0.1 mV/m to 1 V/m with a sampling resolution of 0.03 ms; AC electric field waveform measurements up to 2 MHz with a sampling resolution of 32 ms; continuous monitoring of the dominant frequency and amplitude of high-frequency waves with a time resolution of 0.03 ms; measurement of the thermal plasma density (1-10^5 cm-3) and temperature with up to 0.5 ms and 1 s time resolution, respectively; measurement of the density fluctuations over a dynamic range of 0.1-20 % with a time resolution of at least 1 ms; measurements of time delays between different antennae with time resolution down to 0.03 ms; and wavelength measurements for frequencies up to 20 kHz using on-board interferometric techniques and multiple sensor separations. The FAST electric field instrument stopped providing meaningful data around 2002.

FAST电场仪配备十个传感器，其中每个四根29米长的径向金属线杆（分别位于24米和29米处）上安装有两个，两个3米长的刚性轴向杆上也各安装有一个。除了最外层的四个传感器外，其余传感器均可作为收集电流的朗缪尔探针运行。此类仪器曾在S3-3、ISEE-1、CRRES、Polar和Cluster任务中搭载。该仪器旨在提供以下功能：对电场进行矢量测量，从直流至约20 kHz频率范围，动态范围为0.1 mV/m至1 V/m，采样分辨率为0.03 ms；对交流电场波形进行测量，频率高达2 MHz，采样分辨率为32 ms；连续监测高频波的主频率和振幅，时间分辨率为0.03 ms；测量热等离子体密度（1-10^5 cm^-3）和温度，分别以0.5 ms和1 s的时间分辨率进行；测量密度波动，动态范围为0.1-20%，时间分辨率至少为1 ms；测量不同天线之间的时间延迟，时间分辨率可达0.03 ms；以及使用机载干涉测量技术和多个传感器间距对高达20 kHz频率的波长进行测量。FAST电场仪于2002年左右停止提供有意义的观测数据。