Precise LEO Space Radiation Monitoring using the Space RadMon-NG Payload

Space radiation has an enormous effect on the design considerations of space systems. It is one of the main causes of anomalies in spacecraft, meaning the environment in space needs to be accurately monitored and modelled. Total Ionizing Dose effects on electronics have been known for a long time, however in 1974 Single Event Effects were observed for the first time in digital electronics. This type of radiation effect was caused by a interaction of Galactic Cosmic Rays with the device. Small-scale radiation monitoring in space has previously been done by means of a RADFET sensor for Total Ionizing Dose, or by means of a Timepix sensor for measurement of higher energy particles. These devices were limited in terms of resolution, need relatively high bias voltages, have high power consumption and have high costs. CERN has developed a new type of radiation monitoring payload suitable for Cube- Sats, to make advances in space radiation monitoring. This device was originally based on the RadMon, a radiation monitoring device that is used in various facilities around CERN with the most famous one being the Large Hadron Collider tunnel. CERN developed the Space RadMon-NG, a Commercial-Off-The-Shelf components based CubeSat pay- load. The payload contains a high resolution Floating Gate Dosimeter to measure the Total Ionizing Dose and a SRAM sensor to measure the High Energy Hadron fluence. At the start of the thesis re- search, there were still unanswered questions regarding this payload. The thesis research was per- formed at CERN on the Space RadMon-NG with the goal of answering the question: "How can the Space RadMon-NG payload make significant advances in space radiation monitoring compared to cur- rent state-of-the-art?". To answer this question, a thorough literature review has been conducted, a deep analysis of the payload itself, multiple system-level tests at the CHARM facility at CERN, a separate temperature characteriza- tion test of the Floating Gate Dosimeter sensor at the Cobalt-60 facility and analysis of the payload data retrieved in orbit by the predecessor of the Space RadMon-NG in the CELESTA mission. The testing went mostly according to expectations and all requirements set before testing were verified in different campaigns. The biggest challenges encountered during the system-level testing at the CHARM facility were communication and cabling issues. For the temperature testing of the Floating Gate Dosimeter in the Cobalt-60 facility the biggest challenge was getting the set-up working and the condensation because of the temperature changes. Based on the research performed, the following conclusions can be made. The payload has very good improvements to current state-of-the-art, both in terms of sensor performance and costs. The payload works extremely well in a mixed-field radiation environment, with sensor performances being within 2.5% of the references used. The Floating Gate Dosimeter shows good characteristics when under si- multaneous influence of temperature variations and radiation, showing a performance of withing 2.5% of the reference used when proper compensation is applied. The best compensation technique is based on the reference given by an identical sensor to the floating gate that is not susceptible to radiation but is affected by temperature variations. The CELESTA mission had a resolution that was too low for the orbit mapping of data, but validated the method of analysis for the Space RadMon-NG payload. The new payload is expected to measure a little over 5 Single Event Effects per sensor, per day based on OMERE simulations and the cross-sections measured.