Realizing Laser-driven Deuteron Acceleration with Low Energy Spread via In-situ D_2O-deposited Target

Generation of quasi-monoenergetic ion pulse by laser-driven acceleration is one of the hot topics in laser plasma physics. In this study, we present a new method for the In-situ deposition of an ultra-thin D_2O layer on the surface of an aluminum foil target utilizing a spherical D_2O capsule. Employing a 10^19 W/cm^2 laser, we achieve the acceleration of 10.8 MeV deuterons with an energy spread of ΔE/E = 4.6 shot. The energy spread depends on the exposure time of the D_2O capsule in the vacuum chamber. This method is simple in setup and operation, and has the potential to extend its applicability to other ion species.