First beam tests of the INS split coaxial RFQ for radioactive nuclei

A 25.5-MHz split coaxial RFQ has come into operation at INS. This linac was designed so as to accelerate ions with a charge-to-mass ratio greater than 1/30 from 2 to 172 keV/u. The maximum intervane voltage so far achieved is 91 kV. We have conducted acceleration tests by using Ne/sup +/ and N/sup +/ ions. Through N/sup +/ acceleration we obtained the following preliminary results. The output-beam emittances are well in the design ellipses of 0.06 /spl pi/ cm/spl middot/mrad (normalized). The data of transmission efficiency vs intervane voltage agree well with PARMTEQ results. The transmission at the nominal voltage is measured to be 90%.