TY - CONF AU - Kondo, C. AU - Fukami, K. AU - Fukui, T. AU - Nakazawa, S. AU - Nishimori, N. AU - Saji, C. AU - Takano, S. AU - Tanaka, H. AU - Watanabe, T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Digital Control System of High Precision Magnet Power Supply for SPring-8-II J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - For the SPring-8 upgrade plan, SPring-8-II, a variety of magnet power supplies (PS) from 10 W to larger than 100 kW with a high current stability of about 10 ppm (pk-pk, typ.) are required. In order to develop the PSs within a given time and budget, we plan to use a common control system based on a digital control technology that can be adopted for the variety and the high precision PSs. The system consists of a high-precision analog-digital converter (ADC) circuit and a field programmable gate array (FPGA). Since the precision of the ADC circuit determines the current stability of the PS, we first developed the ADC circuit of high accuracy of less than 10 ppm (pk-pk). A proportional-integral (PI) control logic and a digital pulse width modulation (PWM) function was implemented in the FPGA firmware. These functions can be easily modified for each power supply by a desktop computer. We prototyped a DC power supply equipped with the newly developed digital feedback control system and confirmed that the current fluctuation was suppressed to less than 10 ppm (pk-pk). In the presentation, we will report the current status and future perspective of our power supply development including the evaluation results of the new circuits and the power supply we have developed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1259 EP - 1262 KW - controls KW - feedback KW - power-supply KW - FPGA KW - synchrotron-radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP014 UR - http://jacow.org/ipac2019/papers/tupmp014.pdf ER - TY - CONF AU - Nishimori, N. AU - Tanaka, H. AU - Watanabe, T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - A Highly Brilliant Compact 3 GeV Light Source Project in Japan J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A highly brilliant compact 3 GeV light source project was proposed in Japan. The light source would be constructed in Sendai, north-east part of Japan. It provides brilliant soft X-ray beam to widely cover wavelengths ranging from EUV to hard X-ray in Japan together with SPring-8. The accelerator system is now mostly designed except for several linac components and so on. We have chosen a 4-bend achromat lattice to achieve a low emittance keeping a small circumference with a rather relaxed space issue. The number of cells is 16 and the ring circumference is about 350 m. Number of available beam lines are 26 including short straight sections for multi-pole wigglers. Horizontal emittance is expected to be around 1.1 nmrad, and the maximum brilliance may exceed 10²¹ at 1 - 3 keV region with a stored current of 400 mA. The designs of many components such as vacuum chambers, magnets and monitors are employed from those studied for SPring-8 upgrade project. A full energy injector linac equipped with a thermionic gun and C-band accelerating structures is employed to produce sufficiently low emittance beams for efficient beam injections. The C-band system is adopted from those developed for XFEL SACLA with some modifications. In the future, the injector would be upgraded as an electron driver for SXFEL. Details of the project and accelerator system will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1478 EP - 1481 KW - emittance KW - cavity KW - storage-ring KW - injection KW - linac DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW035 UR - http://jacow.org/ipac2019/papers/tupgw035.pdf ER - TY - CONF AU - Aoyagi, H. AU - Furukawa, Y. AU - Takahashi, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Evaluation and Reduction of Influence of Filling Pattern on X-Ray Beam Position Monitors for SPring-8 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - SPring-8 constantly provides various several-bunch mode operations, which combine single bunches and train bunches. Recently, influence of filling pattern on the accuracy of the XBPMs became apparent, so that we started a systematic evaluation. It was found that the influence was caused by suppression of current signal due to space charge effect, which could be quantified by observing a behaviour of the current signal while changing the voltage of photoelectron collecting electrodes. In order to mitigate the space charge effect, we examined some methods, such as, changing operation parameters of the XBPMs and the undulators. As a result, we successfully reduced the influence of filling pattern. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2526 EP - 2528 KW - space-charge KW - storage-ring KW - operation KW - electron KW - undulator DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW027 UR - http://jacow.org/ipac2019/papers/wepgw027.pdf ER - TY - CONF AU - Fukui, T. AU - Hara, T. AU - Hasegawa, T. AU - Hosoda, N. AU - Inagaki, T. AU - Maesaka, H. AU - Matsubara, S. AU - Morimoto, O. AU - Ohshima, T. AU - Okada, K. AU - Tajiri, Y. AU - Tanaka, H. AU - Tanaka, S. AU - Yamaga, M. AU - Yoshioka, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The Design of the Control System for the SACLA/SPring-8 Accelerator Complex to Use the LINAC of SACLA for a Full-Energy Injector of SPring-8 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - At the SPring-8 site, the X-ray free electron laser facili-ty, SACLA, and the third-generation light source, SPring-8 storage ring, have been operated. On the SPring-8 up-grade project we have a plan to use the linac of SACLA as a full-energy injector of the storage ring. To achieve the SACLA’s user operation and the beam injection to the storage ring in parallel, it is necessary to control the beam energy and the peak current on a pulse by pulse. The demand for an injection occurs anytime during the top-up operation of the storage ring. For this purpose, two accel-erators should be controlled seamlessly and the SACLA has to provide the low emittance electron beam to gener-ate X-ray laser and to be an injector of the storage ring simultaneously. Because SACLA has to control the beam energy and peak current on a pulse by pulse, we are de-signing a system to meet these requirements. A master controller stores a pattern of parameters required for the low-level RF controllers. Each pattern consists of 60 rows which correspond to the parameters for one second with a beam repetition rate of the SACLA, 60Hz. The master sends the parameters to the controllers with reflective memory. We can select the pattern every second on de-mand and it is flexible enough for the top-up operation of the storage ring. Also the data of low-level RF and beam position monitor are stored into the database with a beam repetition rate. In this paper, we report the design of con-trol system for SACLA/SPring-8 to control the beam energy and the peak current on a pulse by pulse. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2529 EP - 2531 KW - controls KW - database KW - operation KW - storage-ring KW - injection DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW029 UR - http://jacow.org/ipac2019/papers/wepgw029.pdf ER - TY - CONF AU - Maesaka, H. AU - Fukui, T. AU - Hara, T. AU - Hasegawa, T. AU - Hosoda, N. AU - Inagaki, T. AU - Kondo, C. AU - Matsubara, S. AU - Morimoto, O. AU - Ohshima, T. AU - Okada, K. AU - Tajiri, Y. AU - Tanaka, H. AU - Tanaka, S. AU - Yamaga, M. AU - Yoshioka, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - On-Demand Beam Route and RF Parameter Switching System for Time-Sharing of a Linac for X-ray Free-Electron Laser as an Injector to a 4th-Generation Synchrotron Radiation Source J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We have an upgrade plan of the SPring-8 storage ring to provide much more brilliant X-rays with a low-emittance electron beam. Since the upgraded ring requires a low-emittance injection beam, we are planning to timeshare the linac of the X-ray free electron laser (XFEL) facility, SACLA, as an injector for the upgraded ring. The SACLA linac delivers low-emittance and short-bunch electron beams to two XFEL beamlines with a 60 Hz repetition rate. The beam route is right now equally changed by a kicker magnet at a switchyard. The beam parameter is also optimized for each XFEL beamline by changing RF parameters pulse-by-pulse with simple software at this moment*. Since the number of beam injection shots to the storage ring is much less frequent than XFEL shots, one of the XFEL shots must be overridden by an injection with on-demand basis. In addition, the beam quality, such as 1 mm mrad normalized emittance, 10 fs bunch length and 10 kA peak current, must be maintained not to deteriorate the XFEL performance. Therefore, we have developed an on-demand beam route and RF parameter switching system with sufficient speed, precision and reliability. A beam route data is transmitted to each accelerator unit by a reflective memory network, and special software changes the parameters of each accelerator unit pulse-by-pulse according to the received data. We tested the on-demand switching system at a test bench and the SACLA linac. The beam parameters were appropriately controlled with a negligible failure rate. The user service of the beam injection from SACLA to SPring-8 is scheduled in 2020 and the on-demand switching system is almost ready for the time-sharing operation of multiple XFEL beamlines and a SPring-8 injection. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3427 EP - 3430 KW - linac KW - FEL KW - electron KW - injection KW - controls DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THYYPLS1 UR - http://jacow.org/ipac2019/papers/thyypls1.pdf ER -