Development of a real-time beam profile monitor for GeV photons and its application in accelerator facilities

TL;DR

This paper introduces a real-time beam profile monitoring system for GeV photon beams using novel plastic scintillation fiber detectors and high-speed data acquisition, achieving high precision and enabling improved beam diagnostics in accelerator facilities.

Contribution

The paper presents a new beam profile monitor system with high-precision, real-time measurement capabilities, integrating novel detectors and data acquisition for GeV photon beams at an accelerator beamline.

Findings

Achieved 10 μm beam-profiling accuracy in real-time.

Successfully detected high-intensity photon beams at tens of MHz.

Demonstrated the system's potential for future accelerator experiments.

Abstract

A real-time beam profile monitoring system is proposed for GeV photon beams at the BM4 beamline of the Mikamine site, Research Center for Accelerator and Radioisotope Science (RARiS; previously known as ELPH) at Tohoku University. This monitoring system enhances the capability to monitor the entire beamline by incorporating newly developed beam profile monitors (BPMs) for upstream and midstream sections, in addition to the existing high-speed BPM used for downstream monitoring. This paper reports on the detection mechanisms of the newly developed BPMs and the actual measurement results obtained using the integrated beam monitoring system. The new BPMs are composed of plastic scintillation fibers and silicon photomultipliers, enabling high-precision, real-time measurements. Data acquisition utilizes streaming TDC, a firmware commonly employed in the J-PARC Hadron-hall, allowing real-time detection of high-intensity photon beams with count rates reaching several tens of MHz. With sufficient statistical data, the BPM achieved a 1-s beam-profiling accuracy of 10 {\mu}m. The proposed BPM system serves as a valuable resource for future physics experiments at the BM4 photon beamline and will significantly contribute to ongoing accelerator research endeavors.