Photocurrents obtained from a triple planar probe sensor for in situ extreme ultraviolet (EUV) radiation measurements on low Earth orbiting CubeSats

Abstract

Purpose – In the Earth’s upper atmosphere, damage to satellite electronics is caused by exposure to extreme ultraviolet (EUV) radiation. One particular region where this type of radiation occurs is the South Atlantic Magnetic Anomaly region. As a result, there is a need to design and develop a sensor which could be used to investigate the flux and energy levels of radiation in this region. To do so, the aim of this study is to characterise the sensor and its electric response to typical EUV radiation levels based on the photoelectric effect principle. Design/methodology/approach – For this purpose, a copper plate planar sensor prototype with dimensions that fit on the sides of a one-unit (1U) CubeSat was constructed. The sensor prototype was placed in a vacuum chamber and was subjected to continuous radiation from a vacuum ultraviolet deuterium light source at test facilities available in the Western Cape region (South Africa). Subsequently, the terminal voltage of the sensor was measured and compared with theory. Findings – The measured time-averaged terminal voltages indicate the generation of photocurrents of the order of 1 A, which is consistent with theory. Originality/value – Conclusively, these results validate the measurement approach and operation of the sensor, which can be used to design a 1U CubeSat sensor that measures EUV radiation in low Earth orbit.