分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: In building Shanghai Synchrotron Radiation Facility (SSRF), in order to reduce or eliminate the unnecessary sources of beam motion, the precise and stable beam position measurement system in the feedback system was required. In this study, we focused on theoretical analysis of the electrode of beam position monitor (BPM). Simulations, including analytic derivations of the propagation impedance and the distribution inductance, were performed. The BPM was designed based on the results and the acceptance measurements of the impedance and the inductance by using the time domain reflection (TDR) with a network analyzer. It has been proved in years of operations that the BPM system meets the requirement of the resolution of sub-micron.
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Shanghai Synchrotron Radiation Facility (SSRF) will implement its Phase II beamline project in the near future. Two long straight sections of the SSRF storage ring will be installed with dual-canted insertion devices in this project. Double-mini-y optics in the long straight sections is designed and optimized in order to obtain high brightness and good machine performance. In this paper, the results are summarized. The Phase II project proposes a lattice upgrade of super-bend, and the double-mini-y optics with this upgraded lattice is presented, too.
分类: 核科学技术 >> 核探测技术与核电子学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Beam current dependence resulted from nonlinearity and asymmetry of the four channels of digital BPM (Beam Position Monitor) processor deteriorates the BPM performance. A systematic solution based on signal source calibration tactics has been carried out to rectify this defect. It is optimized for implementation in FPGA. Mathematical illustrations of the calibration method, hardware and software design and implementation are presented. A signal source circuit using frequency synthesis technique is designed as calibration standard. Data acquisition system using JAVA web technology and Ethernet is introduced. Integrated FPGA implementation code architecture is presented, and experimental test results show that the method implemented in FPGA is feasible. Compared to other methods, our approach can rectify the nonlinearity and asymmetry simultaneously. The whole solution is integrated into the DBPM processor and can be executed online.
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Beam position monitors (BPMs) have been widely used in all kinds of measurement systems, feedback systems and other areas in particle accelerator field these days. The malfunction of a single BPM can cause serious consequences such as the failure of the orbit feedback and the transverse feedback. A troubleshooting has been made to prevent the defective BPMs from affecting the accuracy and stability of the storage ring in Shanghai Synchrotron Radiation Facility (SSRF). Different types of malfunctions have been successfully identified by using the idea of principal component analysis (PCA).
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: In the near future, the Phase-II beamline project of Shanghai Synchrotron Radiation Facility (SSRF) will be implemented and some dipoles in the storage ring will be replaced by high field dipoles (super-bend), so as to leave room for short straight sections. In this way, the brightness of the hard x-ray emitted from the super-bends can be enhanced, and more insertion devices can be installed. In this paper, super-bends of two lengths are discussed and the corresponding lattices are presented.