Broad Energy-Band Ions in the Ourter Heliosphere and Their Coupling with Turbulence

Abstract

This paper focuses on the theme of “solar wind in the heliosphere and its interaction with the invading interstellar wind”，and discusses it from three aspects：current cognition，frontier problems，and exploration suggestions. The ions in the heliosphere include primary solar wind ions，pick-up ions converted partially from interstellar wind，and super-thermal ions. Among them，pick-up ions and super-thermal ions have their contribution from the local interstellar medium flow. The deep-space spacecraft have detected the prevalence of two modes in the heliosphere：the inner boundary of the heliosphere，the solar wind，the interplanetary turbulence，and the energy spectrum of the super-thermal ions. There are three types of cutting-edge issues：① the territory never reached，that is，the tail of the heliosphere in the ecliptic plane and the outer heliosphere at high latitudes；② the territory that has been reached，but some key variables have not been detected，such as the picked-up ions in the outer heliosphere；③ the territory and variables that have been reached and detected，but the formation mechanism is unknown，such as the power-law spectrum and dual-mode of the super-thermal ions. To address these problems，we put forward the following suggestions：① to design different flight paths and detect in different directions；② to carry ion spectra instruments with wide energy band，covering the primary solar wind plasma，the pick-up ions，and the super-thermal ions；③ to carry high sensitivity magnetometer to measure the compressible magnetic turbulence in the outer heliosphere.

Keywords

outer heliosphere / interstellar wind / particle spectrum