分类: 物理学 >> 核物理学 提交时间: 2025-03-10
摘要: This paper presents a technique for extracting the initial parameters of the longitudinal phase space of freshly injected bunches in an electron storage ring. This technique combines the development of a single-bunch injection phase space simulation software with the establishment of a bunch-by-bunch data acquisition and processing system, enabling high-precision acquisition of the initial parameters of injected bunches during the injection process into the electron storage ring (including initial phase, initial bunch length, initial energy offset, initial energy spread, and initial energy chirp). The experiment utilizes a high-speed oscilloscope to capture the beam injection signals, which are then processed by a data processing script to calculate and extract the phase and bunch length evolution information of the injected bunches. The data acquisition length covers several thousand turns per capture, with a phase measurement accuracy of 0.2 ps and a bunch length measurement accuracy of 1 ps. Additionally, a single-bunch simulation software based on the mbtrack2 and PyQt5 packages has been developed. This software can simulate the phase space evolution of bunches under different initial conditions after injection. By employing a genetic algorithm and integrating experimental data with simulation data, it can obtain the optimized initial parameters of the injected bunches.
分类: 物理学 >> 核物理学 提交时间: 2025-04-17
摘要: Resonant cavity monitors are widely used in Free Electron Lasers (FELs) and proposed for linear collider for high-resolution position and phase measurements. The read-out electronics is a main limiting factor affecting system performance. A prototype cavity monitor system with direct RF sampling electronics was developed for C-band cavity beam arrival monitors used in SHINE, operating at the TM010 monopole mode frequency of 3.52GHz.The direct RF sampling electronics simplifies the otherwise complex RF front-end applying traditional down-conversion electronics. The direct RF sampling processor use ADCs with -3dB bandwidth of 9 GHz, a maximum sampling rate of 2.6 GSPS, and 8 bits ENOB at 3.52 GHz. A theoretical analysis demonstrates that the direct-digital down-conversion electronics achieves comparable performance to analog RF down-converters, with online beam tests at SXFEL confirming its high sensitivity. The relative amplitude error of the electronics is 1.3× 10^-4 at 80 pC, and the relative phase error is 8.4 fs. Even with a beam charge of 1 pC, the relative amplitude error of the electronics is better than 1.0× 10^-3, and the relative phase error is 47.7 fs. It paves the way for large-scale applications of direct RF sampling electronics in SHINE. This represents a significant advancement in beam instrumentation at SHINE, leading to both a reduction in project costs and an enhancement in system reliability.
分类: 物理学 >> 核物理学 提交时间: 2025-01-23
摘要: Resonant cavity monitors are widely used in Free Electron Lasers (FELs) and proposed for linear collider for high-resolution position and phase measurements. The read-out electronics is a main limiting factor affecting system performance. A prototype cavity monitor system with direct RF sampling electronics was developed for the C-band cavity beam arrival monitors used in SHINE. The diopole-mode frequency of the cavity is 3.52 GHz. The direct RF sampling electronics simplifies the otherwise complex RF front-end applying traditional down-conversion electronics. The direct RF sampling processor use ADCs with -3dB bandwidth of 9 GHz, a maximum sampling rate of 2.6 GSPS, and 8 bits ENOB at 3.52 GHz. A theoretical analysis shows, that the direct-digital down-conversion electronics should have the same performance as an analog RF down-converter, and on-line beam tests at SXFEL verified its high sensitivity. The relative amplitude error of the electronics is 1.3× 10-4 at 80 pC, and the relative phase error is 8.4 fs. Even with a beam charge of 1 pC, the relative amplitude error of the electronics is better than 1.0× 10-3, and the relative phase error is 47.7 fs. It paves the way for large-scale applications of direct RF sampling electronics in SHINE. This represents a significant advancement in beam instrumentation at SHINE, leading to both a reduction in project costs and an enhancement in system reliability.