Over 2800 days in space – the RAMIS radiation detector on the DLR Eu:CROPIS mission

Kurzfassung

RAMIS (size: 140x140x35mm3, mass: 608 gram, power consumption 1.8 Watt) is a radiation detector developed for the DLR Eu:CROPIS satellite mission. RAMIS uses an arrangement of two silicon detectors in telescope geometry and maps the radiation environment in the course of the mission. For this RAMIS stores count- and dose rate data with a 1-minute and energy deposition spectra with a 5-minute cadence. Eu:CROPIS was launched on December 03rd 2018 into a polar orbit circling around Earth at an average altitude of ~600 km. RAMIS is located on the outside of the satellite and was activated on December 05th 2018 and has continuously provided data during the course of the mission. Due to the polar orbit of the satellite RAMIS measures a) the variation of galactic cosmic radiation (GCR) in dependence on the orbit, b) the contributions of protons in the inner Earth radiation (Van Allen), c) variations of the trapped electron intensity during crossings of the outer radiation belt and finally (d) the changes in the radiation environment due to the changes in the solar cycle as seen in a high number of detected Solar Particle Events (SPE). Using a machine learning algorithm, the complex radiation environment could be classified into GCR, radiation belts and SPEs. Using these data, the long-term changes of the low Earth orbit (LEO) radiation environment in the course of the solar cycle will be presented, and we will also show comparisons to the data from NASA’s Cosmic Ray Telescope for the Effects of Radiation (CRaTER), ESA’s Standard Radiation Environment Monitor (SREM) on Proba-I and the LEO-DOS instrument on the NextSat-2 satellite.