“…Up to now, several schemes for generating energetic protons/ions from laser-solid interaction have been proposed, e.g., target normal sheath acceleration (TNSA), radiation pressure acceleration (RPA), Coulomb explosion acceleration [7], collisionless shock wave acceleration [8][9][10], acceleration with mass-limited target [11][12][13], acceleration via relativistic-induced transparency [14] or breakout afterburner (BOA) [15], and laser ion acceleration with low density targets [16][17][18], laser wakefield acceleration [19], etc., as well as a combination of two or more of these schemes. Most experimental results have been obtained in the TNSA regime [20][21][22][23][24][25][26][27][28][29], which uses relatively thick targets, such as a few or tens of micrometers.…”