Efficient proton-carbon ions acceleration by the plasma-beat-wave mechanism in the presence of the axial magnetic field.

It is possible to generate the low-divergence ion bunches through the interaction of equally or slightly different counter-propagating laser pulses. In this paper, in the framework of plasma beat wave, we have numerically simulated the simultaneous acceleration of carbon/hydrogen ion beams. Using a two-dimensional particle-in-cell simulation, we have shown that in an HC plasma mixture with an optimal hydrogen ratio of 1:5, the laser reflectivity coefficient reduces up to about 4.6%. This condition may provide the acceleration of low-divergence H⁺ and C⁴⁺ ions beam. The cut-off energy for protons and C⁴⁺ ions are about 27 MeV and 410 MeV, respectively at n _H = 0.2 n _C. The values increase by about 15.6% for protons and 21% for C⁴⁺ at n _H = 0.7 n _C. In the presence of an axial magnetic field, the energy absorption arrives at its maximum at the values of Ω_s/ ω _p = 0.1, where Ω_s and ω _p are the gyro-frequency and plasma frequency, respectively. Here, the average kinetic energy of the accelerated ions raises by 17.9% and 7.3% for carbon and proton ions, respectively. Compared to the magnetic field-free case, divergence angles were suppressed at approximately 24.2% and 20.3% for the carbon ions and hydrogen ions, respectively. [ABSTRACT FROM AUTHOR]