Modelling the acceleration and transport of energetic particles near an interplanetary CME
Abstract
When a fast coronal mass ejection (CME) propagates through interplanetary space, it may drive a shock wave which can act as a powerful ion accelerator. In that case, increased levels of turbulence may efficiently trap particles at the shock front where they can gain energy through diffusive shock acceleration. In addition, the strong magnetic enhancement at the shock can act as an efficient magnetic mirror, potentially trapping the ions for a prolonged amount of time between the Sun and the CME shock. This, among other processes, can strongly affect the in-situ observed properties of the associated gradual solar energetic particle event. In this work, we use PARADISE (PArticle Radiation Asset Directed at Interplanetary Space Exploration) to model the transport and acceleration of ions near a CME propagating through interplanetary space. In PARADISE, energetic particle distributions are calculated by solving the focused transport equation in a prescribed background solar wind. We use the three-dimensional magnetohydrodynamic model EUHFORIA (EUropean Heliospheric FORecasting Information Asset) to generate a solar wind in which CMEs of different speeds are injected. In this study, we focus on the acceleration and transport of low- energy protons (< 1 MeV), as these particles may still undergo substantial diffusive shock acceleration in interplanetary space. We investigate how different parallel and cross-field diffusion conditions at the CME shock front affect the obtained particle intensity profiles measured by virtual observers located at various positions in the heliosphere.
- Publication:
-
43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E.903W