RF systems of the TRIUMF ISAC facility

Five RF systems, each operating in CW mode, have so far been specified for the ISAC accelerator system; a pre-buncher, an RFQ, a MEBT re-buncher, five DTL cavities and three DTL bunchers. The pre-buncher was designed and built to operate at a frequency of 11.66 MHz plus three harmonics. So far it has operated successfully at full nominal voltage with fundamental plus the addition of two harmonics. Both the 8-meter long, 4-rod, split-ring type RFQ and the spiral two gap MEBT re-buncher were designed to operate at 35 MHz. The initial 2.8 meters of the RFQ (7 out of 19 rings) were installed in the 8 m long tank and have been successfully operated at full power with beam. Dark currents associated with field emission initially accounted for 40% extra power consumption at full voltage but could be eliminated with high power pulse conditioning.