Speaker
Description
The RADiation-hard Electron Monitor (RADEM) was launched aboard the European Space Agency (ESA), JUpiter ICy moons Explorer (JUICE) on April 14th, 2023. JUICE is scheduled to arrive at the Jovian system in 2031 after an eight-year cruise. RADEM is part of the JUICE platform payload, and for that reason, will be on during the entire cruise and nominal phases of the mission. To characterize the interplanetary radiation environment and the Jovian radiation belts, the instrument carries three detector heads, the Electron Detector Head, the Proton and Ion Detector Head and the Directional Detector Head, each designed to measure electrons from 300 keV to ~40 MeV, protons and ions from ~5 MeV/nucl. to ~250 MeV/nucl, and electron directional distribution from 300 keV to 2 MeV, respectively.
Since the JUICE mission launch, RADEM has observed dozens of solar energetic particle (SEP) events between 0.63 and 1 A.U. However, from the ground-calibration results we were unable to reconstruct the particle fluxes from the measurements made by the three detector heads. For this reason, we carried out a flight-calibration campaign using galactic cosmic rays (GCRs) to obtain accurate calibration coefficients of each sensor. With the results, we reconfigured the instrument to improve energy and particle discrimination.
In this presentation, we will discuss the methods used, including obtaining the GCR flux using a combination of the BON2020 model and the Advanced Composition Explorer (ACE) Cosmic Ray Isotope Spectrometer instrument, and the results. We will also show the comparison between RADEM and other instruments such as the Energetic and Relativistic Nuclei and Electron instrument aboard the Solar and Heliospheric Observatory (SOHO) mission during the September 2024 SEP events, which validated the response functions, and the flux reconstruction methods developed.
