Optical Transition Radiation Monitor for the T2K Experiment

TL;DR

This paper presents an optical transition radiation monitor designed for the T2K neutrino experiment, enabling precise, non-invasive measurement of a high-energy proton beam in a radioactive environment.

Contribution

It introduces a novel optical system that transports light from a harsh environment to a safe area for beam monitoring in the T2K experiment.

Findings

Achieved beam position measurement precision better than 500 μm.

Successfully operated in a highly radioactive environment near the T2K target.

Provided reliable 2D imaging of a 30 GeV proton beam.

Abstract

An Optical Transition Radiation monitor has been developed for the proton beam-line of the T2K long base-line neutrino oscillation experiment. The monitor operates in the highly radioactive environment in proximity to the T2K target. It uses optical transition radiation, the light emitted from a thin metallic foil when the charged beam passes through it, to form a 2D image of a 30 GeV proton beam. One of its key features is an optical system capable of transporting the light over a large distance out of the harsh environment near the target to a lower radiation area where it is possible to operate a camera to capture this light. The monitor measures the proton beam position and width with a precision of better than 500 {\mu}m, meeting the physics requirements of the T2K experiment.