Coupled ion acceleration and Alfv′en wave excitation at an expanding coronal shock

摘要

Selfconsistent quasilinear theory for the formation of a gradual event consisting of solar energetic particles (SEPs) accelerated at an expanding coronal shock driven by coronal mass ejection is presented. The time-dependent ion transport equation and a wave kinetic equation are solved numerically in a spherical geometry. It is shown that the most high energy ions are produced at a distances of less than 4 solar radii above the photosphere. Soon after their acceleration the most energetic ions escape into the undisturbed interplanetary medium. These escaped particles are observed at the Earth’s orbit as a SEPs. It is shown that the model reproduces the observed features of gradual SEP events.