High Energy Proton and Helium Spectra from SOHOs Electron Proton Helium Instrument

High energy protons and Helium in the heliosphere originate from multiple sources. Solar Energetic Particle events (SEPs), Anomalous Cosmic Rays (ACRs) and Galactic Cosmic Rays (GCRs) are prominent examples. Their energy spectra provide insights into acceleration and transportation processes. The SOlar and Heliospheric Observatory (SOHO) was launched December 1995 with the Electron Proton Helium INstrument (EPHIN) measuring protons and Helium from 4 MeV/nuc to 52 MeV/nuc with an additional open ended integral channel. However, its measuring capability was reduced due to the loss of two detectors in 1997 and 2017, respectively. Using Pulse Height Analysis (PHA) data in the integral channel, we present methods to derive energy spectra for protons up to more than 100 MeV and Helium spectra up to some 250 MeV/nuc. First results and comparisons to other instruments will be presented. The SOHO/EPHIN project is supported under Grant 50 OC 2102 by the German Bundesministerium für Wirtschaft through the Deutsches Zentrum für Luft- und Raumfahrt (DLR). This study has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101004159 (SERPENTINE).