Recent progress in the development of large area silica aerogel for use as RICH radiator in the Belle II experiment

TL;DR

This paper reports on the recent development and testing of large-area silica aerogels with specific refractive indices for use as Cherenkov radiators in the upgraded Belle II detector's RICH system.

Contribution

It presents the successful production and optical characterization of large-area silica aerogel tiles for the Belle II RICH detector upgrade.

Findings

Produced approximately 450 aerogel tiles with targeted refractive indices.

Conducted optical characterization of the aerogel tiles.

Tested installation in a mock-up support structure.

Abstract

We report recent progress in the development of large-area hydrophobic silica aerogels for use as radiators in the aerogel-based ring-imaging Cherenkov (A-RICH) counter to be installed in the forward end cap of the Belle II detector, which is currently being upgraded at the High Energy Accelerator Research Organization (KEK), Japan. The production of approximately 450 aerogel tiles with refractive indices of either 1.045 or 1.055 was completed in May, 2014, and the tiles are now undergoing optical characterization. Installation of the aerogels was tested by installing them into a partial mock-up of the support structure.