Beam based calibration of X-ray pinhole camera in SSRF

TL;DR

This paper introduces a new beam-based calibration method for the X-ray pinhole camera at SSRF, enabling online determination of the point spread function width to improve beam diagnostics.

Contribution

A novel beam-based calibration technique for the X-ray pinhole camera that allows real-time measurement of the point spread function width.

Findings

Enables online calibration of the PSF width.

Improves accuracy of electron beam size measurements.

Enhances stability monitoring of the SSRF storage ring.

Abstract

The Shanghai Synchrotron Radiation Facility (SSRF) contains a 3.5-GeV storage ring serving as a national X-ray synchrotron radiation user facility characterized by a low emittance and a low coupling. The stability and quality of the electron beams are monitored continuously by an array of diagnostics. In particular, an X-ray pinhole camera is employed in the diagnostics beamline of the ring to characterize the position, size, and emittance of the beam. The performance of the measurement of the transverse electron beam size is given by the width of the point spread function (PSF) of the X-ray pinhole camera. Typically the point spread function of the X-ray pinhole camera is calculated via analytical or numerical method. In this paper we will introduce a new beam based calibration method to derive the width of the PSF online.