The integrated Miniaturized Electrostatic Analyzer‐Reflight (iMESA‐R) is a space weather instrument designed to measure plasma density, temperature, and spacecraft charging, along with total ionizing dose and dose rate. A constellation consisting of five nearly identical instruments has been designed and developed to act as science payloads hosted on‐board Department of Defense satellites operating in low‐Earth orbit. To validate the dosimetry component of the iMESA‐R, a radiation test study was performed to calibrate the dosimeter and ascertain the attenuation due to the instrument aluminum housing. An 80 curie Cobalt‐60 radioisotope source emitting beta, X‐ray, and gamma ray radiation decay products was used to calibrate the dosimeter response as a function of distance and instrument shielding. We present results of the calibration study along with initial on‐orbit data presented from the first operational iMESA‐R hosted on‐board Space Test Program Satellite 5 in a polar Earth orbit. The initial on‐orbit data demonstrate the ability to map the radiation environment, particularly the South Atlantic Anomaly and the auroral regions using total ionizing dose rate due to electrons of E > 1.5 MeV and protons of E > 25 MeV.

中文翻译：

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使用iMESA‐R进行空间辐射剂量测定的校准和初步结果

集成的微型静电分析仪-反光（iMESA-R）是一款太空气象仪器，旨在测量血浆密度，温度和航天器的电荷以及总电离剂量和剂量率。已设计并开发了由五种几乎相同的仪器组成的星座，以充当科学载荷，这些载荷承载在近地轨道上运行的国防部卫星上。为了验证iMESA-R的剂量学组成部分，进行了辐射测试研究，以校准剂量计并确定由于仪器铝制外壳而引起的衰减。发射出β，X射线和γ射线辐射衰减产物的80居里钴60放射性同位素源用于校准剂量计响应，该响应是距离和仪器屏蔽的函数。我们介绍了校准研究的结果，以及从极地轨道上的第一个运行中的iMESA-R卫星5上载有空间测试计划卫星的卫星提供的初始轨道数据。初始在轨数据证明了能够利用总电离剂量率绘制辐射环境，特别是南大西洋异常和极光区域的辐射图，因为E  > 1.5 MeV，质子E  > 25 MeV。