Detection of Energetic Particles in the Outer Heliosphere and its Boundaries

Abstract

The origin，acceleration and propagation of energy particles in the heliosphere/solar system has always been one of key frontier topics in physics and space physics. An exploration of the outer heliosphere and local interstellar medium will provide crucial information to investigate this frontier topic. In its boundaries，the energy particles originating from the heliosphere are mainly divided into two groups: solar wind suprathermal particles and energy neutral atoms（ENAs）. These energy particles can strongly mediate the morphology and dynamics of the outer boundaries of heliosphere. However，key observations is still lacking，suah as in-situ detection of solar wind suprathermal particles and ENA imaging in the outer boundaries of heliosphere. Based on the high-resolution detection of solar wind suprathermal particles and high-resolution ENA imaging of the Earth’s magnetosphere by the STE instrument on the STEREO satellite，a new-generation semiconductor detectors with low energy thresholds is proposed，combined with the RHESSI’s imaging concept to achieve the ENA imaging and in situ observations of suprathermal particles with high time，energy and angle resolutions in the outer heliosphere. These observations will provide key information to understand the dynamic evolution of the interaction between the heliopshere and local interstellar medium，as well as the origin，acceleration，and propagation of energy particles in the heliosphere.

Key words： energetic partilces; outer boundaries of the heliosphere; energetic particle detection in space

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