Performance of the diamond-based beam-loss monitor system of Belle II

TL;DR

This paper presents the design, construction, and operational performance of a diamond-based beam-loss monitor system at Belle II, which safeguards the detector and accelerator while providing background data.

Contribution

The paper introduces a novel diamond sensor system for beam-loss monitoring, demonstrating its effectiveness during accelerator commissioning and physics data collection.

Findings

System successfully monitors radiation dose-rates near detectors

It effectively protects detector and accelerator components

Provides valuable background information during operation

Abstract

We designed, constructed and have been operating a system based on single-crystal synthetic diamond sensors, to monitor the beam losses at the interaction region of the SuperKEKB asymmetric-energy electron-positron collider. The system records the radiation dose-rates in positions close to the inner detectors of the Belle II experiment, and protects both the detector and accelerator components against destructive beam losses, by participating in the beam-abort system. It also provides complementary information for the dedicated studies of beam-related backgrounds. We describe the performance of the system during the commissioning of the accelerator and during the first physics data taking.