J. Odagiri

Present Status of the J-PARC Control System

The present status of the design and construction of the control system for Japan Proton Accelerator Research Complex (J-PARC) is given. J-PARC is a 3-stage accelerator complex with a 200MeV Linac, a 3GeV Rapid Cycling Synchrotron (RCS) and a 50GeV Main Ring synchrotron (MR). The accelerators are under construction jointly by Japan Atomic Energy Research Institute (JAERI) and KEK, High Energy Accelerator Research Organization. Linac and RCS are being constructed mainly by JAERI and MR is mainly by KEK. [1,2] And the control systems for Linac and RCS [17] are constructed mainly by JAERI and that of MR is done mainly by KEK. [3] Commissioning of Linac, RCS and MR are scheduled in September 2006, May 2007, and January 2008, respectively. There are three control systems under construction corresponding to three accelerators. These three control systems will be operated from one central control room when each control system is completed construction. We chose Experimental Physics and Industrial System (EPICS) [4] as the software environment so that three control systems can be unified easily to single control system. J-PARC control system has the three-layer standard model architecture for accelerator controls that is very common in the EPICS world. We have chosen the standard network protocol TCP/IP and UDP/IP as the J-PARC standard field-bus used to connect interface units that links accelerator component to the control system.

KEKB accelerator control system

The KEKB accelerator control system including a control computer system, a timing distribution system, and a safety control system are described. KEKB accelerators were installed in the same tunnel where the TRISTAN accelerator was. There were some constraints due to the reused equipment. The control system is based on Experimental Physics and Industrial Control System (EPICS). In order to reduce the cost and labor for constructing the KEKB control system, as many CAMAC modules as possible are used again. The guiding principles of the KEKB control computer system are as follows: use EPICS as the controls environment, provide a two-language system for developing application programs, use VMEbus as frontend computers as a consequence of EPICS, use standard buses, such as CAMAC, GPIB, VXIbus, ARCNET, RS-232 as field buses and use ergonomic equipment for operators and scientists. On the software side, interpretive Python and SAD languages are used for coding application programs. The purpose of the radiation safety system is to protect personnel from radiation hazards. It consists of an access control system and a beam interlock system. The access control system protects people from strong radiation inside the accelerator tunnel due to an intense beam, by controlling access to the beamline area. On the other hand, the beam interlock system prevents people from radiation exposure by interlocking the beam operation. For the convenience of accelerator operation and access control, the region covered by the safety system is divided into three major access control areas: the KEKB area, the PF-AR area, and the beam-transport (BT) area. The KEKB control system required a new timing system to match a low longitudinal acceptance due to a low-alpha machine. This timing system is based on a frequency divider/multiply technique and a digital delay technique. The RF frequency of the KEKB rings and that of the injector Linac are locked with a common divisor frequency. The common divisor frequency determines the injection timing. The RF bucket selection system is also described. r 2002 Elsevier Science B.V. All rights reserved.

Porting EPICS to L4-linux based system

Experimental Physics and Industrial Control System (EPICS) is now widely used for many accelerator control systems. While the current and the former versions of EPICS have required VxWorks to run core software on input/output controllers (IOCs), the next version (R3.14) is to be portable to many other platforms. Considering the recent trend toward Linux, it is an attractive candidate for the port. However, the Linux kernel cannot ensure real-time responsiveness because it dose not preempt the execution from a process that is running in the kernel. As an alternative, we adopted 4-Linux, a port of Linux. onto a real-time rnicro-kemel (LA), as the platform. With some adaptation, LA-Linux allows any EPICS thread to benefit from either the real-time scheduling by L4 or the many functions of Linux. The adaptation of L4-Linux to the real-time use, the interface libraries between the IOC software and L4-Linux, and a library to support the VMEbus are described. A preliminary result of the measurement of interrupt latency is also presented.

Manufacturing and Operation of the Magnetic Septa for the Slow Beam Extraction From the J-PARC 50 GeV Proton Synchrotron

The magnetic septa have been developed for the slow beam extraction from the 50 GeV Proton Synchrotron to the Hadron Experimental Hall at J-PARC (Japan Proton Accelerator Research Complex). The magnetic septa consist of two thin magnetic septa, four medium thick magnetic septa and four thick magnetic septa. The typical operating current is 3000 A and the total kick angle is 77 mrad with the 30 GeV proton beam. All parts of the thin and of the medium thick septum magnets are made of inorganic materials to resist high radiation environment. The positions of the thin and medium thick septa can be aligned remotely in the horizontal range of ±5 mm, which enables us to minimize the beam loss at the magnetic septum section. The septa were installed in the synchrotron ring in December, 2008, after a test at KEK (High Energy Accelerator Research Organization), and were successfully operated in the beam time for the slow beam extraction in January and February, 2009, which resulted in the first 30 GeV slow extracted beam delivery to the Hadron Experimental Hall.

The Construction of the SuperKEKB Magnet Control System

There were more than 2500 magnet power supplies for KEKB storage rings and injection beam transport lines. For the remote control of such a large number of power supplies, we have developed the Power Supply Interface Controller Module (PSICM), which is plugged into each power supply. It has a microprocessor, ARCNET interface, trigger signal input interface, and parallel interface to the power supply. The PSICM is not only an interface card but also controls synchronous operation of the multiple power supplies with an arbitrary tracking curve. For SuperKEKB we have developed the upgraded version of the PSICM. It has the fully backward compatible interface to the power supply. The enhanced features includes high speed ARCNET communication and redundant trigger signals. Towards the phase 1 commissioning of SuperKEKB, the construction of the magnet control system is ongoing. First mass production of 1000 PSICMs has been completed and their installation is in progress. The construction status of the magnet control system is presented in this report. (1) Introduction ----Original PSICM KEKB, the asymmetric electron-positron collider for B-meson physics, started in operation in Dec.1998 and finished in Jun. 2010. KEKB control system was EPICS-based, using more than 100 VME/VxWorks computers as IOC (I/O Controller). About 2500 magnet power supplies were installed in the KEKB storage rings and the injection beam transport lines and controlled by 11 IOCs. To connect such many power supplies to the IOCs, we adopted ARCNET as the field bus and developed the PSICM (Power Supply Interface Controller Module). . Original PSICM New PSICM Microprocessor AM186 MPC8306 Clock frequency 20MHz 133MHz Data memory 256kB SRAM 128MB DDR2 SDRAM Program memory 256kB EPROM 64MBit NOR FLASH ARCNET interface 2.5Mbps Backplane mode 2.5Mbps/5Mbps/10Mbps Backplane mode Controller COM20020 COM20022 Media driver HYC2485 HYC5000 Power required 5V 0.4A 5V 1A ARCNET Interface board (4 ch. / boards)