The Relativistic Electron-Proton Telescope (REPT) Investigation: Design, Operational Properties, and Science Highlights

The Relativistic Electron-Proton Telescope (REPT) instruments were designed to measure similar to 2 to >18 MeV electrons and similar to 18 to > 115 MeV protons as part of the science payloads onboard the dual Radiation Belt Storm Probes (RBSP) spacecraft. The REPT instruments were turned on and configured in their science acquisition modes about 2 days after the RBSP launch on 30 August 2012. The REPT-A and REPT-B instruments both operated flawlessly until mission cessation in 2019. This paper reviews briefly the REPT instrument designs, their operational performance, relevant mode changes and trending over the course of the mission, as well as pertinent background effects (and recommended corrections). A substantial part of this paper highlights discoveries and significant advancement of our understanding of physical-processes obtained using REPT data. We do this for energetic electrons primarily in the outer Van Allen belt and for energetic protons in the inner Van Allen zone. The review also describes several ways in which REPT data were employed for important space weather applications. The paper concludes with assessments of ways that REPT data might further be exploited to continue to advance radiation belt studies. The paper also discusses the pressing and critical need for the operational continuation of REPT-like measurements both for science and for space situational awareness.

Automated summary

This paper briefly reviews the design, operational performance, mode changes and trends of the REPT instruments, as well as corrections for relevant background effects. It highlights significant discoveries and advancements in understanding physical processes obtained using REPT data, particularly for energetic electrons in the outer Van Allen belt and energetic protons in the inner Van Allen zone. The paper also discusses the importance of continuing REPT-like measurements for both science and space situational awareness.