Energetic Particle Instrument (EPI)

Physically part of the Three dimensional plasma analyzer (3DA) instrument, EPI consists of an array of
solid-state telescopes measuring electrons and ions in the energy range 20 - 226 keV and 20 - 400 keV, respectively,
in 6 energy channels and 4 angle channels at a time. During each spacecraft spin the telescopes trace out a large
fraction (70%) of the solid-angle sphere. The EPI instrument (together with the 3DA instrument) is a derivative of
the 3D Plasma and Energetic Particle Instrument on the WIND spacecraft.

EPI，作为三维等离子体分析仪（3DA）仪器的物理组成部分，由一组固态望远镜阵列构成，该阵列测量电子和离子在20 - 226 keV和20 - 400 keV的能量范围内，分别以6个能量通道和4个角度通道同时进行。在每次航天器的自转过程中，望远镜能够扫描出约70%的球面立体角。EPI仪器（连同3DA仪器）是WIND航天器上3D等离子体与高能粒子分析仪的衍生产品。