Energetic ion acceleration with a non-Maxwellian hot-electron tail

A half-self-similar solution on the bases of the equations of the continuity and motion of ions and Poisson’s equation is proposed for isothermal expansions of nonquasineutral plasmas with an enhanced electron tail into a vacuum from solid targets heated by ultraintense laser pulses. The ion expansion is assumed to be self-similar, while the electron expansion is non-self-similar. The expression of the self-similar variable and maximum ion velocity at the ion front is given out. It is shown that the ion acceleration with an enhanced hot-electron tail is more efficient than that with Maxwellian electrons.