CURRENT STATUS OF TARLA CONTROL SYSTEM

Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) is a Free Electron Laser (FEL) facility designed to generate Free Electron Laser (FEL) in 3-250 um wavelength range, based on four 9-cell Super Conducting (SC) cavities with 10MeV/m gradient each. TARLA electron gun has been in operation since 2012[1]. Control system studies with EPICS are being run as test stand control and permanent system and each are running as individual projects while test stand control is in stable revision. The aim of the system design is to create a fast and reliable control system which is easy to operate and extensible for future upgrades/improvements. Now, the development and implementation of control system is ongoing in a parallel manner with the rest of the accelerator as well as the architectural design, In this study, the permanent and the test stand control systems of TARLA will be discussed. TARLA CONTROL SYSTEM TARLA control will be held by an in-house developed EPICS based system running under Linux OS on industrial PC’s. The reason EPICS was chosen as main environment is commitment to next generation accelerators as well as the distributed structure and high performance capabilities.[2] Design point is to create an easy to use/maintain, soft IOC style, fast, stable and extendible control system suitable for laser generation and beam diagnostics as well as gathering control and monitor requirements of all auxiliary systems. Control system studies are divided into two parallel aspects; to design a complete system for TARLA from scratch (requirement analysis and architectural design is completed, hardware selection and device support development is ongoing) and to develop a minor system as prototype for e-gun test stand (alpha version is released in March 2014). Architectural Design Figure 1 shows the intended conceptual design of TARLA control system where IOC’s are soft servers running on Linux machines. In accordance with EPICS philosophy system will be designed in a distributed manner where extension for repetitive tasks are held via macros. Personal Safety System (PSS) which is also EPICS based, will be a stand alone system acting like a supervisor for operator interface to enable/disable operation start-up. Interlock will be developed in a layered structure where lower layer DSP is responsible for machine protection and a higher ∗ Work supported by Ministry of Development of Turkey † ekazanci@ankara.edu.tr layer EPICS IOC for interlock status logging and a soft interlock for extensibility.CentOS 6.3 and OpenSuse 13.1 are being used for development machines along with EPICS base 3.12.4, synApps R5−7 and StreamDevice2. For client operations CSS will be used (version bundled for SNS). Beam diagnostics cameras are selected as GigE compliant with PoE option. For EPICS integration AravisGigE module and AreaDetector are being tested. Naming convention and class hierarchy has been established. Main communication protocols for TARLA are RS232, TCP/IP and RS485 where backbone is composed of CISCO 49 series fast ethernet switches and TCP/IP to RS232 or TCP/IP to RS485 converters, therefore Streamdevice and Asyn module combination is highly critical and relied upon throughout the facility. All of the devices are being chosen SCPI compatible where available. Figure 1: Architectural design of TARLA control system. In order to meet time constraints we aim to use devices with Linux drivers already written and avoid preparing EPICS device support as much as possible where a remote host/target approach is not suitable. In this manner we are currently porting NI DAQ hardware device support to CentOS 6.3 obtained from ITER project CODAC public tarball. For low priority GPIO, we intend to use RaspberryPi derivatives and for this purpose we have written a general purpose EPICS device support by using WiringPi I/O library which will be released shortly. E-gun Test Stand Control via EPICS A control system for TARLA e-gun test stand has been released in alpha version in March 2014. The system is capable of producing and controlling the electron beam in DC/CW or macropulsed mode but has no diagnostic capabilities yet. In terms of control system aware devices e-gun 5th International Particle Accelerator Conference IPAC2014, Dresden, Germany JACoW Publishing ISBN: 978-3-95450-132-8 doi:10.18429/JACoW-IPAC2014-THPRO127