Devices for high precision x-ray beam intensity monitoring on BSRF

TL;DR

This paper discusses the development and comparison of high-precision ion chamber devices for monitoring x-ray beam intensity at BSRF, aiming to achieve uncertainty below 0.1% in synchrotron radiation metrology.

Contribution

It introduces novel high-precision ion chamber devices and compares different signal collection methods for accurate x-ray beam intensity measurement.

Findings

Direct current reading and signal amplification methods were compared.

The study achieved control of measurement uncertainty under 0.1%.

Different ion chamber sizes and gases were evaluated for optimal performance.

Abstract

Synchrotron radiation with the characteristic of high brilliance, high level of polarization, high collimation, low emittance and wide tunability in energy has been used as a standard source in metrology(1, 2). For a decade, lots of calibration work have been done on 4B7A in Beijing Synchrotron Radiation Facility (BSRF) (3, 4). For the calibration process, a high-precision online monitor is indispensable. To control the uncertainty under 0.1%, we studied different sizes parallel ion chambers with rare-gas and used different collecting methods to monitor the x-ray intensity of the beamline. Two methods to collect the signal of the ion chambers: reading the current directly with electrometer or signal amplification to collect the counts were compared.