Beam test results of the INS RFQ/IH linac

A linac complex for radioactive beams has been constructed at INS, which comprises a 25.5-MHz split coaxial RFQ (SCRFQ) with modulated vanes and a 51-MHz interdigital-H (IH) linac . The SCRFQ accelerates ions with a charge-to-mass ratio (q/A) greater than 1/30 from 2 to 172 keV/u. The beam from the SCRFQ is charge-stripped by a carbon-foil, and is transported to the IH linac through two magnetic-quadrupole doublets and a 25.5-MHz rebuncher cavity. The IH linac accelerates ions with a q/A greater than 1/10, and the output energy is variable in the range of 0.17 through 1.05 MeV/u. Beam tests of the linac complex performed with N ions show that the output beam energy and transmission efficiency agree well with predictions.