A laser ion source that provides a fully ionized carbon ion beam is under joint development at the High Energy Accelerator Research Organization and Brookhaven National Laboratory. Long-pulse (6 ns) and short-pulse (500 ps) laser systems were tested by using them to irradiate a graphite target. Notable differences between the systems were observed in these experiments. Preliminary experimental results, such as the charge-state spectrum, beam intensity, and stability, are discussed.

Fully stripped carbon ions generated in a laser-ablation ion source are directly injected into a smallscale induction synchrotron. Carbon-ion beams of C 6þ , C 5þ , and C 4þ are trapped in the barrier bucket. Beam properties, such as the momentum spread and beam lifetime in the low-energy ring, are measured and discussed in relation to the essential characteristics required in a carbon driver for future carbon therapies.

To investigate efficient graphite material for carbon ion production in laser ion source, the plasma properties produced from these materials are measured. Comparing acquired current profile and charge state distribution, the distributions of ions in laser induced plasma from isotropic graphite and single crystal of graphite are different. The produced quantity of C(6+) from isotropic materials is larger than that from single crystal.