Software Redundancy for Machine Interlock System of KOMAC

The Korea multi-purpose accelerator complex (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 10 beam lines, 5 for 20-MeV beams and 5 for 100-MeV beams. The radiation of the beam loss and faults of the linac components can cause substantial damage to the devices. Therefore, the KOMAC active protection system needs to minimize the beam loss radiation and ensure the safe operation of the machine. The purpose of an interlock system is to turn off beam and components when an interlock occurs. The software-based interlock system was design to double-check a MPS operation and support sequential operation by interlock signals. The interlock system is based on hardware and software interlock system with redundancy to protect the sensitive devices from the radiation on the beam loss and faults on the equipment. The local MPS for a main interlock have been fabricated, and its response time was within 3 μs. This response time has been satisfied to meet the machine protection, which must prevent a beam within a few milliseconds during beam operation of 60 Hz. The interlock systems can inhibit a beam whenever one of the control systems detects an error from the local devices. A beam can be accelerated under machine and personnel protection condition