Development of a Machine Protection System for KOMAC Facility

The Korea multi-purpose accelerator complex (KOMAC) 100 MeV proton linac has been developed and installed at the Gyeong-ju site [1]. The KOMAC consists of low-energy components, including a 50 keV ion source, a low-energy beam transport (LEBT), a 3 MeV radio-frequency quadrupole (RFQ), and a 20 MeV drift tube linac (DTL), as well as high-energy components, including seven DTL tanks for the 100 MeV proton beam. The KOMAC includes ten beam lines, five for 20 MeV beams and five for 100 MeV beams. The KOMAC utilizes a high power, heavy-ion linear accelerator to support diverse beam service, including a radio-isotope beam line and provides beams of 100 MeV with a beam power > 100 kW [2]. Therefore, in the event of operating failure, it is extremely important to shut off the beam to prevent damage to accelerator components such as the linac cavities and diagnostic equipment. The KOMAC machine protection system (MPS) is required to protect the high-performance accelerator components. The MPS developed previously with an analog circuit interlock box was upgraded to a digital interlock system [3]. We designed the new MPS to be flexible enough to accommodate both machine study and beam operations. In case of a beam abort, the KOMAC MPS inhibits all relevant devices to protect the accelerator components against beam losses, thereby avoiding damage leading to long maintenance times. In this paper, we present the KOMAC machine protection architecture, technical specification, and performance results of the new machine protection system.