Emittance measurements for RIKEN 28 GHz SC-ECRIS

In order to investigate the ion optical parameters of the beam line of RIKEN 28 GHz SC-ECR ion source into the new heavy ion linac (RILAC II), we measured the emittance of the heavy ion beams from RIKEN 28 GHz SC-ECR ion source. In the test experiments, we observed that the emittance of the U35+ beam was ∼100π mm-mrad (4 rms emittance), which is smaller than the acceptance of the accelerator (∼160π mm-mrad). The emittance with 28 GHz was almost same as that with 18 GHz and independent on the injected RF power (1-2 kW). The size of emittance increased with decreasing the charge state. We also measured the emittance of U and O ions under the same condition. In this experiment we observed that the emittance of O ions was always larger than the U ion beam for same M/q. In this contribution, we report the experimental results for emittance measurement of highly charged U, Xe and O ions from RIKEN 28 GHz SC-ECR ion source in detail. (author)