On July 25, 2013, the Alphasat satellite was launched, carrying the component technology test-bed (CTTB) to assess the space radiation effects in electronic components. Embedded in each of the three experimental boards of the CTTB, are radiation-sensitive metal-oxide–silicon field-effect transistors (RADFETs) to measure the radiation levels at the Alphasat geostationary orbit (GEO). In this work, values of accumulated dose are presented for the RADFETs onboard the Alphasat CTTB experiments up to July 16, 2018. These values were calculated from the threshold voltage shift and from temperature data transmitted to Earth, and using the model derived, previously, from the ESAPMOS4 RADFETs calibration campaign conducted at the European Space Research and Technology Centre (ESTEC) Cobalt-60 facility. These results show that the current accumulated doses are between 1.9 and 3.2 krad and the average dose rates are between 40 and 70 mrad/h. We also present a polynomial function that allows converting voltages into doses for a wide range of values and for different temperatures. The quality of this conversion is tested against Geant4 simulations of the expected dose in the CTTB components for the space radiation environment at the Alphasat orbit. The simulated doses were obtained for three GEO radiation models: AE8, AE9, and IGE-2006.

中文翻译：

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Alphasat CTTB 实验上 RADFET 响应的剂量测量和模拟

2013 年 7 月 25 日，Alphasat 卫星发射升空，搭载了组件技术试验台（CTTB），用于评估电子组件的空间辐射效应。CTTB 的三个实验板中都嵌入了辐射敏感金属氧化物硅场效应晶体管 (RADFET)，用于测量 Alphasat 地球静止轨道 (GEO) 的辐射水平。在这项工作中，提供了截至 2018 年 7 月 16 日的 Alphasat CTTB 实验上 RADFET 的累积剂量值。 这些值是根据阈值电压偏移和传输到地球的温度数据计算得出的，并使用先前导出的模型，来自在欧洲空间研究与技术中心 (ESTEC) Cobalt-60 设施进行的 ESAPMOS4 RADFET 校准活动。这些结果表明当前累积剂量在 1.9 到 3.2 krad 之间，平均剂量率在 40 到 70 mrad/h 之间。我们还提出了一个多项式函数，它允许将电压转换为各种值和不同温度的剂量。这种转换的质量是针对 Alphasat 轨道空间辐射环境的 CTTB 组件中预期剂量的 Geant4 模拟进行测试的。模拟剂量是针对三个 GEO 辐射模型获得的：AE8、AE9 和 IGE-2006。这种转换的质量是针对 Alphasat 轨道空间辐射环境的 CTTB 组件中预期剂量的 Geant4 模拟进行测试的。模拟剂量是针对三个 GEO 辐射模型获得的：AE8、AE9 和 IGE-2006。这种转换的质量是针对 Alphasat 轨道空间辐射环境的 CTTB 组件中预期剂量的 Geant4 模拟进行测试的。模拟剂量是针对三个 GEO 辐射模型获得的：AE8、AE9 和 IGE-2006。