The monitoring system for the aerogel Cherenkov counter of the BELLE detector

TL;DR

This paper describes a monitoring system for the aerogel Cherenkov counters in the BELLE detector, ensuring stable and uniform LED light distribution to maintain detector performance.

Contribution

It introduces a reliable LED-based monitoring system with a diffuser box to improve light uniformity for the BELLE detector's ACC modules.

Findings

High long-term stability of the LED light source

Effective reduction of non-uniformity in light distribution

System meets all performance requirements for monitoring

Abstract

We report on a design and performances of a monitoring system developed for the aerogel Cherenkov counters (ACC) of the BELLE detector. The system consists of blue LEDs, a diffuser box, and optical distributors which distribute the LED light to the ACC modules. The employed LED (NSPB series) has been observed to have high reliability on the long term stability and the temprature dependence. The diffuser box is employed to reduce the intrinsic non-uniformity of the LED light intensity. The overall performances of the present monitoring system on uniformity and intensity of the light output have been found to satisfy all the requirements for the monitoring.