Dispersive Alfven waves ( DAWs ) offer , an alternative to magnetic reconnection , opportunity to accelerate solar flare particles in order to alleviate the problem of delivering flare energy to denser parts of the solar atmosphere to match X-ray observations .
Here we focus on the effect of DAW polarisation , left , right , circular and elliptical , in the different regimes inertial and kinetic , aiming to study these effects on the efficiency of particle acceleration .
We use 2.5D particle-in-cell simulations to study how the particles are accelerated when DAW , triggered by a solar flare , propagates in the transversely inhomogeneous plasma that mimics solar coronal loop .
( i ) In the inertial regime , fraction of accelerated electrons ( along the magnetic field ) , in the density gradient regions is \approx 20 \% by the time when DAW develops three wavelengths and is increasing to \approx 30 \% by the time when DAW develops thirteen wavelengths .
In all considered cases ions are heated in the transverse to the magnetic field direction and fraction of heated particles is \approx 35 \% .
( ii ) The case of right circular , left and right elliptical polarisation DAWs , with the electric field in the non-ignorable transverse direction exceeding several times that of in the ignorable direction , produce more pronounced parallel electron beams ( with larger maximal electron velocities ) and transverse ion beams in the ignorable direction .
In the inertial regime such polarisations yield the fraction of accelerated electrons 20 \% .
In the kinetic regime this increases to 35 \% .
( iii ) The parallel electric field that is generated in the density inhomogeneity regions is independent of the electron-ion mass ratio and stays of the order 0.03 \omega _ { pe } cm _ { e } / e which for solar flaring plasma parameters exceeds Dreicer electric field by eight orders of magnitude .
( iv ) Electron beam velocity has the phase velocity of the DAW .
Thus electron acceleration is via Landau damping of DAWs .
For the Alfven speeds of V _ { A } = 0.3 c the considered mechanism can accelerate electrons to energies circa 20 keV .
( v ) The increase of mass ratio from m _ { i } / m _ { e } = 16 to 73.44 increases fraction of accelerated electrons from 20 \% to 30 - 35 \% ( depending on DAW polarisation ) .
For the mass ratio m _ { i } / m _ { e } = 1836 the fraction of accelerated electrons would be > 35 \% .
( vi ) DAWs generate significant density and temperature perturbations that are located in the density gradient regions .
DAWs propagating in the transversely inhomogeneous plasma can effectively accelerate electrons along the magnetic field and heat ions across it .