Design and Evaluation of a Monitoring Instrument for the High-Energy Proton and TID Effects in LEO

In this paper, we introduce the development and evaluation of the Proton Environment and Total ionizing dose (TID) Effect Monitor (PETEM) onboard a low Earth orbit (LEO) satellite for telecommunication test launched on 20th May 2022. The PETEM was developed to supply in-situ probe data of space environment and its effects for the space application of commercial off-the-shelf (COTS) components. At the same time, it is expected that the data can be useful for analyzing the proton distribution in South Atlantic Anomaly (SAA) and inner radiation belt. PETEM possesses the function of detecting high-energy protons and TID effects in LEO. Geant4 simulation was employed to design the semiconductor telescope of high-energy proton detector, which was designed to measure protons in the energy range of 5∼200 MeV. A circuit was developed to improve the accuracy of radiation-sensitive field-effect transistor (RadFET) measurements by accounting for the temperature dependence of the threshold voltage and calibration results showed its ability to provide reliable and accurate measurements of TID effects in real-time. We also present the results of in-flight tests, indicating that PETEM can reliably measure proton environment and TID effects.