Manipulation of laser-generated energetic proton spectra in near critical density plasma

作者:Palmer Charlotte A J*; Dover Nicholas P; Pogorelsky Igor; Streeter Matthew J V; Najmudin Zulfikar
来源:Journal of Plasma Physics, 2015, 81(01): 365810103.
DOI:10.1017/S0022377814000798

摘要

We present simulations that demonstrate the production of quasi-monoenergetic proton bunches from the interaction of a CO2 laser pulse train with a near-critical density hydrogen plasma. The multi-pulse structure of the laser leads to a steepening of the plasma density gradient, which the simulations show is necessary for the formation of narrow-energy spread proton bunches. Laser interactions with a long, front surface, scale-length (>> c/omega(p)) plasma, with linear density gradient, were observed to generate proton beams with a higher maximum energy, but a much broader spectrum compared to step-like density profiles. In the step-like cases, a peak in the proton energy spectra was formed and seen to scale linearly with the ratio of laser intensity to plasma density.

  • 出版日期2015-1