Laser-driven collisionless shock acceleration of protons

Abstract

Experimental and numerical results have shown that collisionless shock acceleration is promis-ing for generation of high energy proton beams. There are many potential applications for suchbeams, for example: isotope generation for medical applications, ion therapy and proton radio-graphy. In this work, we use 1D1P Eulerian Vlasov-Maxwell simulations to study shock waveacceleration. Vlasov-Maxwell modeling allows for high resolution of the distribution functionand is highly suitable in cases where effects of low-density tails in the distribution function needto be resolved accurately.We find that combining collisionless shock acceleration with a strong, quasi-stationary sheath-field may be a way to reach even higher maximum proton energies and optimize the ion spec-trum. We show that a layered plasma target with a combination of light and heavy ions leads toa strong quasi-static sheath-field, which induces an enhancement of the energy of shock-waveaccelerated ions, without broadening their energy spectrum, if the heavy ion layer has highdensity