Donghyup Ha

Design of Control System for Dual-Head Radiation Therapy

Sungkyunkwan University groups have been developed advanced radiation therapy machine named dual-head radiation therapy gantry for reducing the treatment time by up to 30%. The main difference between previous radiation therapy machine [1] is using two electron LINAC as X-ray sources at radiation therapy. In support of this system, control system based on SCADA and hardware development was implemented. The control system consists of supervisory computers and local controllers and the control network was ethernet and software was written by labVIEW. An overview of this control system is presented in paper. INTRODUCTION Sungkyunkwan University has developed a dual head radiation therapy system since 2012, which is a radiation therapy system that aims to reduce treatment time up to 30% than conventional radiation therapy machine [2]. To reduce treatment time, dual X-ray source, head are equipped with this system. developed dual-head gantry system is shown in Fig. 1. Those system configurations have economic benefits and advantages on account of reducing radiation treatment time but the additional installation of components result in space limit and a complexity of the system. To overcome space limit, we use 6 MeV Xband LINAC as X-ray source and it sufficiently reduce not only cavity volume but also waveguide and magnetron [3]. Controlling dual X-ray source is new challenge. in contrast to conventional TomoTherapy that use single X-ray source, dual head gantry system uses dual X-ray sources ssimultaneously or sequentially so control system requires supervisory control and sequence control that not only include data acquisition and monitoring but also two electron LINAC beam pulse synchronization. Figure 1: Dual-head Radiation therapy system. SYSTEM HARDWARE CONFIGURATION Developed gantry system is consist of subsystems such as two heads, electron LINAC and gantry robot and subsystems have each local controller. Head subsystem objective is to control the radiation path from the LINAC to the patient. It measures radiation dose rate and control X-ray field size. Its appearance is shown in Fig. 2 Head’s main control unit is Atmega2560 and control board has potential meters and limit switches for interlock. Figure 2: Gantry Head Appearance. Five motors in head system have each driver. By using daisy-chain scheme, master motor manages other slave motors as shown in Fig. 3. Figure 3: Gantry head system block diagram. 9th International Particle Accelerator Conference IPAC2018, Vancouver, BC, Canada JACoW Publishing ISBN: 978-3-95450-184-7 doi:10.18429/JACoW-IPAC2018-THPML076

Investigation of Minimized Consumption Power about 10 MeV Cyclotron for Acceleration of Negative Hydrogen

SKKUCY-10 cyclotron with 10 MeV particle energy was designed with purpose of production about fluorodeoxyglucose (FDG). Design strategy was maximization of accelerating voltage in order to secure the turn separation. Magnet had deep valley type, RF cavity had four stems and one RF power coupler. There was internal ion source for compact design of cyclotron. Specification of cyclotron was analysed by simulating particle dynamics for central region and whole system. AVF cyclotron had 83.2 MHz of radio frequency, 1.36 T of average magnetic field, 40 kV of main accelerating voltage. Phase slip between RF and beam was less than 15 degrees, minimum turn separation was over 2 mm. Specifications of both single beam analysis of reference particle and multi-beam analysis of bunch of particles were calculated by using Cyclone v8.4 and CST-Particle studio codes.

PLC Control System for Vacuum and 20 Kw RF Amplifier

In this paper, integrated Vacuum and RF amp local controller has been presented. Integrated Controller provide automated process for amp and vacuum machine by PLC interlock function also realized by using plc module. HMI for integrated controller is also developed using LABVIEW 2014. Its HMI and integrated controller will be replaced from original two independent controller for machine stability and management of interlock. Development of integrated controller will be continuously expand to Low level RF controller. SYSTEM REQUIREMENT Since 2014, the Sungkyunkwan University has been upgrade 10 MeV cyclotron (SKKUCY-10) prototype for producing radio isotopes. For stable and robust cyclotron operation, local controller is main issue. Especially, RF and Vacuum is main part for control system and each sub system fault result in damage to the other sub systems. To solve those problem, we integrate RF amplifier and vacu-um local controller by LS PLC (Programmable Logic Controllers). Integrated Interlock event is also processed at one controller. This paper describe system requirement for RF amplifier and vacuum and discuss the detailed design and software development by PLC programming at SKKUCY -10. Abstract