Bead Pull Measurements of the FETS RFQ at RAL

A Radio Frequency Quadrupole (RFQ) is a part of the Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL), Didcot, UK. The aim of the FETS project is to produce a 60 mA H⁻ beam at 3 MeV. The RFQ is a four-vane type with 4 modules, each of 1 m length, and is designed to accelerate the beam from 65 keV to 3 MeV at 324 MHz. A bead pull system has been designed to measure the field along the RFQ. This will be used in conjunction with 64 tuners to produce a uniform field. In order to optimise the tuning procedure, a model of the RFQ has been creat-ed in COMSOL Multiphysics. This study shows the results from the bead pull measurements and the tuning studies.