Speaker
Mr
Zheng Ting Ang
(TRIUMF)
Description
The TRIUMF ISAC radioactive ion beam facility has been in operation since 2001. The room temperature linear accelerator comprises sixteen independent rf systems and RFQ is the first major system which was installed. The 35 MHz RFQ is designed to accelerate ions of A/q up to 30 from 2 keV/u to 150 keV/u in cw mode. The RFQ structure is 8 meters long and the vane-shaped rods are supported by 19 rings spaced 40 cm apart. The maximum operating inter-vane voltage is 74 kV, which requires 85 kW from the power amplifier. The power amplifier is capable of 150 kW of peak power for pulse rf conditioning. In order to improve reliability of beam delivery and reduce downtime due to rf devices, many improvements have been implemented to the rf amplifiers. In particular, RFQ amplifier has undergone major upgrades over last few years. Dedicated ramping circuit for smooth start up of the HV power supply has made it more reliable. Improved crowbar trigger circuit using two high power SCR has been installed which has made high power conditioning of the RFQ tank lot more easier. A new monitoring system for all relevant parameters of all ISAC-I rf amplifiers was designed and implemented. It consists of a Modicon Momentum PLC system and distributed Advantys I/O system. EPICS interface was established so as to operate and run the rf amplifiers from main control room over PLC interface. During the 2008 Spring Shutdown, new signal samples were added to the RFQ amplifier monitoring, and interface wiring was modified to incorporate this new PLC system. The updated system is undergoing rigorous test. The RFQ tank also went through major repair work. The RFQ vacuum deteriorated from 2*10-7 to 2.7*10-6 between 2003 and 2006 due to small water leaks inside the RFQ tank. The tank was opened and two rings were replaced with identical spare rings. Also water leaks in the supply and return lines were plugged. A cryo pump was installed which improved the vacuum to 1.5*10-7 Torr at full RF power.
Author
Mr
Zheng Ting Ang
(TRIUMF)
Co-authors
Mr
Amiya Mitra
(TRIUMF)
Mr
Joseph Lu
(TRIUMF)
Mr
Yuri Bylinskii
(TRIUMF)