Search

Time-resolved measurements in synchrotron radiation experiments require an RF clock of a storage ring accelerator and a fundamental revolution frequency (zero address) signal. For the usage of these signals around the experimental station, long RF cables from the accelerator timing station, divider modules and delay modules must be deployed. These installations need a lot of cost and require a lot of efforts to adjust the timing by experts. To lower these costs and efforts, the revolution frequency, which is ~209 kHz at the SPring-8 storage ring, and tag information distribution system has been studied based on a high precision time synchronization technology over a network. In this study, the White Rabbit* (WR) technology is adopted. The proof of concept system has been built, which consists of a master PC, a slave PC and two WR switches. The master PC detects the zero-address signal and distributes the time stamps with tag information to the slave PC. Then the slave PC generates the ~209 kHz signals synchronized with the target bunch by adding the offset time by software. The measured one-σ jitter of the output signals from the slave PC has been achieved less than 100 ps., Proceedings of the 12th Int. Workshop on Emerging Technologies and Scientific Facilities Controls, PCaPAC2018, Hsinchu, Taiwan

MADOCA-to-EPICS gateway has been developed for easy and rapid integration of EPICS ready devices into MADOCA, the control software framework for SPring-8 and SACLA. MADOCA uses equipment control software called Equipment Manager (EM) in the device control layer. The MADOCA-to-EPICS gateway is implemented as a general-purpose EM to handle EPICS IOCs. The gateway consists of EM functions that interact with IOCs using Channel Access (CA) protocol corresponding to EPICS commands such as caget, caput and camonitor. We can build the gateway for the target EPICS device by editing the EM configuration file, without any programming. We have applied the gateway to the Libera Brilliance⁺ installed in the SPring-8 storage ring for the evaluation towards the SPring-8 upgrade project. In addition, it has been applied to the Libera Brilliance Single Pass and Spark installed in beam transport line, and the Libera Spark and Cavity installed in SACLA. The gateway brings us the benefits to minimize the installation time and effort even for the different platform (CPU and OS) devices. We will report on the development and advantage as well as the performance improvement of the MADOCA-to-EPICS gateway., Proceedings of the 16th Int. Conf. on Accelerator and Large Experimental Control Systems, ICALEPCS2017, Barcelona, Spain

The optical-link remote I/O system OPT-VME that consists of a VME master and several kinds of slave boards is widely used in SPring-8 and SACLA. As the next generation low-end platform instead of the outdated VMEbus, a Linux PLC such as Yokogawa e-RT3 has been considered. We have developed an e-RT3-based master module OPT-PLC to fully utilize a large number of existing remote boards. In the original system, low-level communication is performed by FPGA and high-level communication procedures are handled in the Solaris device driver on a VME CPU board. This driver becomes a barrier to port the system to e-RT3 platform. OPT-PLC should be handled by the e-RT3 standard driver in the same manner as other e-RT3 I/O modules. To solve the difficulty, OPT-PLC was equipped with Xilinx SoC and the high-level communication procedures were implemented as application software on ARM Linux in the SoC. As the result, OPT-PLC can be controlled through the standard e-RT3 driver. Furthermore, the system will be ported to other platform like PCI Express by replacing bus interface block in the PL part. This paper reports on our development as an approach to maximize cross-platform portability using SoC., Proceedings of the 16th Int. Conf. on Accelerator and Large Experimental Control Systems, ICALEPCS2017, Barcelona, Spain

The RF system of the SPring-8 storage ring has stably generated an accelerating voltage of 16 MV at a frequency of 508.58 MHz since 1997. In the upgrade of the SPring-8, a beam energy is lowered from 8 to 6 GeV and a needed voltage is 7 MV. The upgrade employs multi-bending optics, and shortens the straight sections available for RF accelerating cavities by 30%. On account of the space, the RF system is to be so rearranged that the number of cavities can be reduced to half. The analog low-level RF (LLRF) system in use controls the voltage with sufficiently small deviations of less than 0.1 % in amplitude and less than 0.1 degree in phase, but becomes out-of-dates and hard to be maintained. We plan to replace them with a compact digital LLRF system in the MTCA.4 standard and based on under-sampling scheme. The SACLA linac is used for injecting a low-emittance beam to the ring. Because we have to balance the FEL operation and the beam injection on demand, pulse-by-pulse control of beam parameters is going to be implemented to the SACLA LLRF modules. Furthermore, we build a timing system for injection to a target bucket-position in the ring within a time deviation of 3 ps., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

SPring-8 is a 3rd generation light source which has been operated stably. During user operation, an interlock system which turns off the RF acceleration signal if the beam orbit at insertion devices exceed a window is in operation. Beam abort events due to the interlock system have occurred as a rare event at SPring-8. Though in most cases we find trouble in accelerator devices as the source of the beam orbit shift, sometimes we cannot find any evidence after the beam abort. In order to identify the sources of such aborts, we have developed a system which observe beam orbit along the storage ring during beam abort. The system was realized by modification of the digital part of the existing COD measurement system. Every 1 ms, the system measures beam position at all BPMs with the position resolution of 1 micron or less. This system enabled us to identify the source when a beam abort due to an orbit shift with a time constant of longer than a few milliseconds. Furthermore, this system is applicable to survey sources of beam orbit fluctuations during stable operation. In this proceeding, we describe the system, beam orbit data during beam abort and source analysis., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany