Design of Automatic Beam Transport System at SPring-8 LINAC


At a new accelerator, the best operating parameters have to be found by trial and error. The operator must learn from experience, and it expends much time for operation because the accelerator has many alignments and other errors which are hard to measure. The SPring-8 Linac is also a new accelerator operated since 1996. It’s a 140m long, 1GeV electron machine. The machine is used as an injector into the 8GeV synchrotron. The synchrotron demands high energy stability, so the operator must search for the parameter by trial and error. Even after the parameter is fixed, it is possible that the energy is fluctuated by the temperature and various other reasons, and the operator must engage in adjustment continually[1]. Whenever a parameter is adjusted, the beam profile is also checked on a screen which is made with alumina-ceramic (Desmarquest AF995R). Therefore we design an automatic operation system using screen monitors. Firstly, we develop an image processing system for the screen monitor. Next, we try to do a preliminary automatic control using the system. It is attempted for the electron beam transport. This paper presents the image processing system of screen monitor, and some results of a preliminary automatic control experiment using it. 1 Data acquisition system 1.1 Linac control system and screen monitor system For the data acquisition and low level control of devices, we adopt VME computers. The hierarchy of the control system has two layers. One is the Machine Control Process layer (VME), another is the MMIF layer (EWS) [2]. Figure 1 shows a layout of the system in the Linac. These VMEs have MVME147 boards (Motolora 68030 CPU) and run the OS-9 operating system. An EWS uses HP9000 series. The VME system is located on the second floor which is called the klystron gallery. The 32 screen monitors are installed in the Linac. The monitor is constructed with a CCD camera that sends an image by wire to the control-room. Usually, the image processing for getting the profile is done by shuttered CCD camera[3]. However, we use non-shutter CCD Camera based on NTSC (National Television System Committee) regulation, because it is very expensive to install all screen monitors. The CCD signal is inputed to a VME, and convert to digital data. Video Signal Switcher RS-232C Optical Ether-net CCD CAMERA #1~ #32 LINAC Hardware Control Lines EWS X server

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@inproceedings{Sakaki1998DesignOA, title={Design of Automatic Beam Transport System at SPring-8 LINAC}, author={Hironao Sakaki and Hiroshi Yoshikawa and Hideaki Yokomizo and Takuya Sogo and Kouji Kinoshita and Norihiko Adachi}, year={1998} }