| Paper | Title | Page |
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| TUPMP014 | Digital Control System of High Precision Magnet Power Supply for SPring-8-II | 1259 |
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| 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. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP014 | |
| About • | paper received ※ 16 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019 | |
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| WEPMP009 | Renovation of Off-Axis Beam Injection Scheme for Next-Generation Photon Sources | 2318 |
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Funding: Work supported by Ministry of education, culture, sports, science and technology JAPAN (MEXT). Photon sources are looking for performance upgrades by pursuing higher photon brilliance and coherence these years. The trend is pushing the lattice design to lower the beam emittance, which naturally results in the narrower dynamic aperture. One bottleneck in the upgrades is a beam injection system capable of accumulating required beam intensity and keeping top-up operations with such narrow apertures. Beam injection with a nonlinear kicker and transverse/longitudinal on-axis injections are now in the limelight. However, these techniques still need time to be put into practical use. We take an alternative approach for the SPring-8 upgrade, SPring-8-II, renovating the off-axis beam injection scheme to address the following requirements for the coming diffraction-limited storage rings (DLSRs): minimizing of both injection beam amplitude and perturbation to stored beam, and topping-up functionality. This presentation will overview the renewed off-axis beam injection scheme and report the development status of the following three key components: 1) permanent magnet based DC septum magnet, 2) in-vacuum pulse septum magnet, and 3) twin kickers driven by a single solid state pulser. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP009 | |
| About • | paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
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| THPTS024 | Magnet Developments and Precise Alignment Schemes for SPring-8-II | 4158 |
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| The magnet lattice design of the SPring-8 upgrade, SPring-8-II, is a five bend achromat composed of one normal and four longitudinal gradient bending magnets. Permanent magnet has been chosen for both types of the dipoles, and the high gradient multipole magnets are all electromagnets. This presentation will overview the magnet developments and precise alignment schemes for SPring-8-II, focusing specifically on the following features. Temperature insensitive magnetic circuits with a function of fine magnetic field tuning have been developed for the permanent magnet dipoles. Narrow bore multipole magnets with compact coil assemblies have been designed. We optimized the shimming for enough good field regions, and minimized ohmic loss at the coils for suppressing thermal deformation. To improve the accuracy of vibrating wire magnet alignment, practical wire sag distributions have been quantitatively evaluated. In 2018, a test half-cell was constructed by which the feasibilities of the magnets and the overall alignment precisions including the effects of the thermal deformation of magnets, a repeatability of magnet reassembly has been confirmed. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS024 | |
| About • | paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
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| TUPGW035 | A Highly Brilliant Compact 3 GeV Light Source Project in Japan | 1478 |
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| 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. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW035 | |
| About • | paper received ※ 14 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019 | |
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