This study conducted offline calibration tests on the stripline Beam Position Monitor (BPM) designed for the Hefei Advanced Light Facility (HALF) injector. The Lambertson method was used to measure the off-set between the electrical center and the mechanical center of the BPM, with results showing horizontal and vertical offsets of 0.1154 mm and 0.1661 mm, respec-tively. Additionally, the wire-scan method was em-ployed to construct the BPM mapping, and polynomial fitting was applied to effectively reduce the BPM’s nonlinearity and system errors. The experimental re-sults provide essential data support for the optimiza-tion and practical application of the BPM in the HALF injector.

To address non-standard Gaussian beam spot pro-files in injectors, this paper proposes a fitting algo-rithm based on Gaussian, the newly introduced Gener-alized Gaussian Type and Skewed Gaussian Type dis-tributions. These distributions are specifically de-signed to better fit non-Gaussian and asymmetric beam spots by automatically selecting the most suitable model. Validation using beam spot images from the YAG screen after the electron gun in the Hefei Light Source II (HLS-II) injector demonstrates that the Gen-eralized Gaussian Type is effective for fitting sharp or broad profiles, while the Skewed Gaussian Type is well-suited for handling asymmetry. Compared to tra-ditional methods, the proposed algorithm improves fitting accuracy and adaptability, providing a practical solution for complex beam measurement challenges.

The non-uniformity, longitudinal oscillations, and space charge effects in a multi-bunch filled electron stor-age ring can lead to significant deviations in the meas-urement of longitudinal beam parameters. Selecting a single bunch for measurement can effectively improve the measurement accuracy of longitudinal beam parame-ter, under normal multi-bunch operation mode. This pa-per introduces an optical pulse selection system based on an RTP crystal Pockels cell, which is controlled by fast electronics and high-voltage electronics, to study the complex longitudinal beam dynamics. By adjusting the driving voltage frequency and trigger delay of the high-voltage driver, precise selection of single pulses in a multi-bunch filling mode can be achieved. Offline cali-bration experiments have verified the potential feasibility of selecting specific bunches or bunch trains within the multi-bunch operation, which is of great significance for diagnosing longitudinal characteristics and instabilities of the beam in electron storage rings.

Beam orbit stability is a crucial indicator that can be used to evaluate the performance of a synchrotron radiation source. It can be improved through precise orbit measurement with beam position monitors (BPMs) and appropriate orbit feedback. The move-ment of BPMs directly affects the measurement of the beam orbit and indirectly affects the beam orbit through orbit feedback (OFB) system. Two sets of BPM displacement measurement system were estab-lished at Hefei Light Source II (HLS II) storage ring and some machine learning work was carried out on the system.