Creation of Peaks in the Energy Spectrum of Laser-Produced Ions by Phase Rotation

By focusing a short-pulse (250fs) and high power (240mJ) laser on a thin foil target of Ti 3μm in thickness with laser power density up to 9 x 10W/cm, proton production up to ~900keV was observed by optimization of parameters with the use of TOF measurement. Application of phase rotation to such protons resulted in creation of a few peaks in the energy spectrum and the intensity increase about factor of 3 in the peak positions.