2026-10-14T01:07:22Z https://www.scidb.cn/oai

10.57760/sciencedb.j00186.01135 2026-06-23T12:23:15Z

2026-06-23 Experimental Test Data of the Direct RF Sampling Processor for SHINE Cavity Monitors doi:10.57760/sciencedb.j00186.01135 en This dataset comprises experimental test data from a prototype C-band cavity beam arrival monitor (BAM) system developed for the Shanghai High Repetition Rate X-ray FEL and Extreme Light Facility (SHINE), using a direct RF sampling electronics approach. The beam tests were conducted at the end of the linac section of the Shanghai Soft X-ray Free-Electron Laser (SXFEL) under typical operating conditions (bunch charge ~500 pC).The dataset includes:Raw ADC sampling data: Time-domain waveforms (4096 samples per bunch pulse) and corresponding frequency spectra acquired by the direct RF sampling processor via under-sampling, with the 3.52 GHz cavity signal shifted to 285.9 MHz.Amplitude and phase extraction results: Derived using a fixed-point Goertzel-DFT algorithm. Data include amplitude/phase errors as functions of DFT accumulation points around the peak and different data subset lengths (500–4000 points), used to optimize the processing parameters.Band-pass filter (BPF) necessity evaluation: Comparative measurements with and without an external 3.52 GHz cavity BPF in the signal path, showing that the BPF does not improve performance (amplitude error 1.29×10⁻⁴ and phase error 9.0 fs without BPF vs. 2.25×10⁻⁴ and 12.6 fs with BPF).Performance comparison of RF conditioning modules: Side-by-side comparison of the direct RF amplifier module (gain 24.8 dB, NF 2 dB) and a traditional down-conversion module (gain 22.7 dB, NF 7.5 dB), with both feeding into the same digitizer. Data include amplitude and phase errors for each path.System sensitivity test: Measurements with external attenuators (0–40 dB) before the power splitter to simulate equivalent bunch charges from 80 pC down to 0.8 pC. The resulting relative amplitude and phase errors are provided, demonstrating superior performance even at 1 pC (9.57×10⁻⁴ amplitude error, 47.4 fs phase error).All data were acquired with a common clock synchronized to the SXFEL 119 MHz reference, synthesized to 1.904 GHz for the ADC. The raw data are stored as fixed-point numbers unpacked from JESD204B serial streams via FPGA, and post-processing was performed in Matlab or on-chip. This dataset validates the direct RF sampling scheme for SHINE cavity monitors, showing its advantages in system simplification, cost reduction, and high sensitivity. SHINE; RF sampling; cavity monitor zhou yi mei PUBLIC https://creativecommons.org/licenses/by-nc-nd/4.0/ dataset http://www.doi.org/10.1016/j.nima.2024.169256 Science Data Bank