3D FIELD EFFECTS ON THE MULTIPLE CHARGE BEAM DYNAMICS IN THE SUPERCONDUCTING DRIVER LINAC FOR RIA

MULTI-CHARGE BEAM DYNAMICS The Rare Isotope Accelerator (RIA) driver linac design is being studied at NSCL. In the low energy part of the superconducting linac, transverse steering of the beam in the 80.5 MHz and 161 MHz quarter-wave resonators (QWRs) is caused by the combination of the 3D electric and magnetic rf fields. A transverse rms emittance growth of ~20% is predicted due to the high frequency QWR. Possible modifications to the geometry of the QWR are studied. A detailed beam dynamics analysis of the steering and emittance growth in the whole RIA driver linac was done using LANA code (9). Realistic 3D electromagnetic fields calculated with MAFIA and ANALYST (10) were used in the simulations. Two charge states of uranium 238 U 28,29+