Enhanced laser-driven proton acceleration using ultrasmall nanoparticles

Abstract

An efficient way to enhance laser-driven proton acceleration is by increasing the laser-to-target energy transfer, which can be obtained using nanostructured target surfaces. In this paper, we show that inexpensive and easily producible solid target nanostructuration using ultrasmall nanoparticles having 10 nm in diameter exhibits a nearly twofold maximum proton energy and proton number enhancement. Results are confirmed by particle-in-cell simulations, for several laser pulse lengths. A parameter scan analyzing the effect of the nanoparticle diameter and space gap between the nanospheres shows that the gap has a stronger influence on the enhancement mechanism than the sphere diameter.