Optimization of a beam line equipped with a laser ion source

Progress in high-power short-pulsed laser technology has enabled us to build a high-performance laser ion source, which can provide ion beams with rather high-energy from a high-density plasma. An ion beam produced by the laser source has a wide momentum spread, a small transverse emittance and a large divergence, like a white beam from a point source. A phase-rotation method has been proposed to reduce the momentum spread in order to use the laser-produced ion beam practically under the above conditions. This phase-rotation method inevitably increases the transverse emittance due to sudden compression of the momentum spread in a phase-rotation cavity. We report on beam optics optimization with two kinds of magnetic lens system, solenoid and quadrupole, and compare their performance.