The NASA high energy solar physics (HESP) mission for the next solar maximum

Abstract

The NASA High Energy Solar Physics (HESP) mission offers the opportunity for major breakthroughs in our understanding of the fundamental energy release and particle acceleration processes at the core of the solar flare problem. HESP's primary strawman instrument, the High Energy Imaging Spectrometer (HEISPEC), will provide X-ray and γ-ray imaging spectroscopy, i.e., high-resolution spectroscopy at each spatial point in the image. It has the following unique capabilities; (1) high-resolution (∼keV) spectroscopy from 2 keV - 20 MeV to resolve flare gamma-ray lines and sharp features in the continuum; (2) hard X-ray imaging with 2″ angular resolution and tens of millisecond temporal resolution, commensurate with the travel and stopping distances and times for the accelerated electrons; (3) gamma-ray imaging with 4″–8″ resolution with the capability of imaging in specific lines or continuum regions; (4) moderate resolution imaging of energetic (20 MeV to ∼1 GeV) gamma-rays and neutrons. Additional strawman instruments include a Bragg crystal spectrometer for diagnostic information and a soft X-ray/XUV/UV imager to map the flare coronal magnetic field and plasma structure. The HESP mission also includes extensive ground-based observational and supporting theory programs. Presently HESP is planned for a FY 1995 new start and late 1999 launch, in time for the next solar activity maximum.