Speaker
Description
The problem of particle acceleration at interplanetary (IP) shocks is long-standing, since several unresolved issues are still debated, pushing the research on this field
to jointly explore spacecraft in-situ observations, numerical simulations, and analytical models.
In this work, we analyze several shock crossings by spacecraft in the interplanetary space in order to link the shock and the energetic particle flux properties to the magnetic field turbulence upstream of the shock (namely within the unshocked region). Here a mixture of pre-existing and possible self-generated turbulence induced by the back-streaming motion of energetic particles influences the particle transport and then the acceleration efficiency.
We evaluate the amplitude of magnetic field fluctuations at the scale of non-thermal particles both close to the shock, where self-generated turbulence is expected to dominate, and far upstream, where the particle motion is basically mediated by pre-existing turbulence. Such parameters will be related to the shock compression ratio and to the shock Mach numbers as well as to the particle differential energy spectra. A comparison with an analytical model, based on the transport equation, developed by Ha 2025 will be made and discussed.
