Correction of Galileo Energetic Particle Detector, Composition Measurement System High Rate Data: Semiconductor Dead Layer Correction

The Energetic particle detector (EPD) on-board the Galileo orbiter measured ions in the keV to MeV energy range in Jupiter’s equatorial plane, generating a unique data set. However, as a result of its time in the highly hostile Jovian radiation environment the EPD and its composition measurement system (CMS), suffered damage to its silicon semiconductor detectors. This resulted in misidentification of ion species and an underestimation of fluxes. We use in-flight measurements to understand the nature of the damage and how much it has affected the data. A method of mass and energy identification and reallocation was developed to identify and correct affected data thus improving the usability and accuracy of the Jovian data sets. This study aims to calculate the extent of the damage to the main CMS detector, KT; estimating the build-up of a non-sensitive dead layer on its surface. By the end of mission this dead layer has increased and is estimated to top out at 0.35±0.02 μm. A corrected set of data is produced, which fits better within expected boundaries, and will be made available for future use