UPGRADE OF THE ISAC DTL TUNING PROCEDURE AT TRIUMF

The TRIUMF ISAC facility has two variable energy heavy ion linacs as post accelerators for radioactive ion beams. The ISAC I linac is a warm IH-DTL with five accelerating tanks and three bunchers, the ISAC II linac uses twenty independently phased superconducting cav-ities. The first linac operates between 150keV/u and 1.8Mev/u; the second boosts the 1.5MeV/u injected beam by 20MV. The DTL is tuned based on the energy spectrum from an analysing magnet. The superconducting linac is tuned on energy and time profiles with a diagnostic based on a gold foil scattering ions to a silicon detector. The sili-con requires lower beam intensity. Furthermore the tuning time is reduced and streamlined by means of a MATLAB graphical user interface. This interface uses a simple co-sine model to characterize the energy gain versus RF phase of each cavity. Based on this we have pursued a new tun-ing procedure for the DTL using a gold foil/silicon detector diagnostic. The more complex RF structures of the DTL re-quire measurements and beam dynamics simulations (done with the LANA code) to produce a model for a dedicated MATLAB interface. In the paper we describe the two ex-isting tuning methods and present the new DTL procedure and interface