Young-Gi Song

Fast triggers for a proton injector at PEFP.

A fast timing system has been developed to control transistor transistor logic (TTL) trigger signals which are used to extract the pulsed proton beam from an ion source with the precision of less than submicro seconds. The system has been designed to set a delay and duty of the pulses, respectively, and prohibit the beam pulse by an external interlock signal. The system is based on VME which is composed of VME CPU and fast I/O boards with fan-out modules. The software of the system has been developed by the record/device supports and channel access in the core of the EPICS environments. In the paper, we describe software configurations and hardware drivers.

RF Interlock Implementation Using Digital LLRF System for 100 MeV Proton Linac at KOMAC

Although existing analogue RF interlock board works well and has significance in our linac, we need more flexible platform and method were composed of the digital component. For that, the cavity pickup RF was used to protect the cavity and RF systems because the digital LLRF system already monitors and controls the cavity pickup RF through the FPGA. For turning off the cavity pickup RF when abnormal RF detected, the pickup RF should be monitored and compared with predefined interlock levels as shown in the Fig. 2. For monitoring and comparing the pickup RF, the amplitude of pickup RF was calculated instead of using the In-phase, Quadrature (I, Q) values as it is because the RF phase scanning procedure may occurs when the accelerator needs the phase tuning. Also, the I or Q values may be very small

Commissioning of the RI Production Beam Line of KOMAC

A radioisotope (RI) production beam line has developed at Korea Multi-purpose Accelerator Complex (KOMAC) in 2015 and the commissioning started in 2016. The beam parameters of the beam line are 100 MeV beam energy with a maximum 30 kW beam power, which is driven by KOMAC 100 MeV proton linac. The main components of the beam line are a beam transport system, a target transport system, a cooling system for target and hot cell. KOMAC has a plan to commission the beam line and get an operation license in 2016 and start user service in 2017. In this paper, the development and initial commissioning results of the RI production beam line are presented.

Solid Targetry for the Isotope Production Facility at the KOMAC 100 MeV Linac

The construction of the isotope production facility was recently completed on the 100 MeV proton linac at the KOMAC (Korea Multi-purpose Accelerator Complex). To produce the Sr-82 and Cu-67, we have prepared the solid targetry which consist of target transportation system , target cooling system and a hot-cell for remote handling. The Isotope production targets are made of RbCl pellet, Zn metal disc and stainless steel cladding. For the proton beam irradiation, the targets are transported by target drive system which consist of drive chain and guide rail by remotely. In this paper, we will report the detailed design, fabrication and operation status of the solid targetry at the KOMAC isotope production facility. TARGET PREPARATION To design RI target, we have derived the optimum thickness of target materials considering the beam energy loss by the beam window, cooling water and target claddings through SRIM calculation [2]. Figure 1 describes the typical target configuration for Sr-82 production, which is consisted of 1 RbCl target and aluminum dummy target. Figure 1: Target configuration for Sr-82 production. For the Sr-82 and Cu-67, the pressed RbCl pellet and Zn metal disc was prepared. These target materials have the natural abundance of isotopes and they are encapsulated in stainless steel cladding with o.d. of 60 mm and i.d. of 50 mm with 0.3 mm window for the proton irradiation. To prevent the leakage of the radioactive species inside target claddings, the cladding is fabricated by laser welding. After the target cladding fabrication, the leakage tests have been conducted by using the penetration test. Figure 2 shows the fabricated proto-type target claddings after welding process. (a) RbCl pellet and its target cladding (b) Zn disc and its target cladding Figure 2: The proto-type target for Sr-82 / Cu-67 production.

The Operation Experience at KOMAC

A 100-MeV proton linac at the KOMAC (Korea Multipurpose Accelerator Complex) is composed of a 50-keV microwave ion source, a 3-MeV four-vane-type RFQ, a 100-MeV DTL and 10 target stations for proton irradiation on samples from many application fields. The linac was commissioned in 2013 and the user service started in July 2013 with delivering proton beam to two target stations: one for a 20-MeV beam and the other for a 100MeV beam. In 2015, the linac has been operated more than 2,800 hours with an availability of greater than 89 %. The unscheduled downtime was about 73 hours, mainly due to troubles of ion source arcing and failures of pulsed high voltage power system. More than 2,100 samples from various fields such as materials science, bio-life, nano technology and nuclear science, were treated in 2015. Currently, a new target station for radioisotope production is under commissioning and a new target station for low flux irradiation experiments is being installed. Operational experiences of the 100-MeV linac during the past 3 years will be presented in the workshop.

Alarm Implementation of a HMI(Human Machine Interface) for a Proton Linear Accelerator

The control system of the PEFP proton linear accelerator has to read and write thousands of signals. A large science facility such as a PEFP accelerator has to be secure, accurate, rapid and easily expandable. We need to find a way to design a consistent control system that satisfies the above requirements. We conclude that EPICS is a suitable tool which can be used to develop a control system for an accelerator device. The vacuum control system of the proton linear accelerator periodically displays the status of the system to check the vacuum device in a real time to establish whether it monitors the vacuum data normally or not. This control system uses a database record which contains its current alarm status and the corresponding severity for a status. In this paper, the vacuum control system of the PEFP is summarized and the development of an alarm module is presented