Sequential excitation scheme for laser stripping for a H− beam

A new scheme with sequential resonant excitation for laser assisted charge exchange injection of ${\mathrm{H}}^{\ensuremath{-}}$ beams is proposed. In contrast with the one step excitation scheme, the proposed scheme requires significantly less laser power for high efficiency stripping. It also provides greater flexibility in the choice of laser wavelength for a given beam energy and extends the range of energies where laser stripping can be effectively applied. Calculations and experimental plans for 1.0 GeV and 1.3 GeV ${\mathrm{H}}^{\ensuremath{-}}$ beams at the Spallation Neutron Source are presented. Results indicate that the sequential excitation scheme allows the use of more convenient green laser with much smaller power in place of the UV laser previously used.