Tri-Axial Fluxgate and Search-coil Magnetometers

The FAST magnetic field instrumentation includes a DC fluxgate magnetometer and an AC search coil magnetometer. The fluxgate magnetometer is a three-axis instrument using highly stable low noise ring core sensors. It is boom-mounted at 2 m from the spacecraft body in a shielded housing. It provides magnetic field information from DC to 100 Hz to a 16-bit analog-to-digital converter. Time resolution is 2 ms and the sensitivity below 50 Hz close to 1 nT. The search coil magnetometer (also boom-mounted) uses a three axis sensor system that contains laminated permalloy cores, windings and preamplifiers. The design is based on the OGO-5 instrument with recent developments implemented on classified projects. The signals are further amplified in the electronics before analog-to-digital conversion. An AC magnetic field measurement is provided over the frequency range 10 Hz to 2.5 kHz with a time resolution of 0.1 ms and a frequency-dependent sensitivity between 10^-8 and 10^-10 nT^2/Hz.

FAST 磁场测量仪器集成了直流磁通门磁强计和交流搜索线圈磁强计。磁通门磁强计为一款三轴仪器，采用高度稳定的低噪声环形磁芯传感器。该仪器安装在距离航天器本体2米的悬臂上，置于屏蔽壳体内。它能向16位模数转换器提供从直流到100赫兹的磁场信息。时间分辨率为2毫秒，50赫兹以下的灵敏度接近1纳特。搜索线圈磁强计（同样安装在悬臂上）采用包含叠层坡莫合金磁芯、绕组和前置放大器的三轴传感器系统。该设计基于OGO-5仪器，并在保密项目上实现了近期的发展。信号在模拟到数字转换前在电子设备中得到进一步放大。提供10赫兹至2.5千赫兹频率范围内的交流磁场测量，时间分辨率为0.1毫秒，频率相关的灵敏度介于10^-8至10^-10纳特平方每赫兹之间。