High-energy ions accelerated by 60-fs laser

Abstract

1 MeV proton from thin Cu tape target with 5 μm thickness was observed in the region of laser intensity (α~1.5) and ultra short pulse range of 60 fs. Carbon ion acceleration was also observed and the maximum energy was higher than 0.4 MeV. The energy and charged states of proton and carbon were measured by a Thomson mass spectrometer with CR39. The maximum proton energy seems to depend more on the laser energy density I λ2 τL [J μm2/cm2] than laser intensity I λ2 [W μm2/cm2] in the short pulse region around 100 fs.