RF Characteristics of 433.3-MHz Proton RFQ Linac

A 433.3 MHz proton RFQ linac of four vane type is constructed.The vane length and the inner tank diameter are 2195 mm and 170.4 mm respectively.The quadrupole field balance is analyzed with the equivalent circuit.Twenty-four pick-up loops are used to measure the magnetic field.The field is tuned with twenty-four side tuners and good field balance between each quadrant is obtained.The intervening electrodes, which compensate the decrease of the intervane capacitance at the radial matcher, are tested to improve the longitudinal field distribution.