Recent progress in particle acceleration from the interaction between thin- foil targets and J-KAREN laser pulses

From the interaction between the high-contrast (similar to more than 10(10)) 130 TW Ti:sapphire laser pulse and Stainless Steel-2.5 um-thick tape target, proton beam with energies up to 23 MeV with the conversion efficiency of similar to 1% is obtained. After plasma mirror installation for contrast improvement, from the interaction between the 30 TW laser pulse and thin-foil target installed on the target holder with the hole whose shape is associated with the design of the well-known Wehnelt electrode of electron-gun, a 7 MeV intense proton beam is controlled dynamically and energy selected by the self-induced quasi-static electric field on the target holder. From the highly divergent beam having continuous spectrum, which are the typical features of the laser-driven proton beams from the interactions between the short-pulse laser and solid target, the spatial distribution of 7 MeV proton bunch is well manipulated to be focused to an small spots with an angular distribution of similar to 10 mrad. The number of protons included in the bunch is >10(6).