Optical and radiographical characterization of silica aerogel for Cherenkov radiator

TL;DR

This study characterizes silica aerogels with high transparency and uniformity for Cherenkov radiators using optical and X-ray methods, highlighting the effects of a novel pin-drying process on density distribution.

Contribution

It introduces a pin-drying method to produce high-refractive-index, transparent, hydrophobic silica aerogels and evaluates their uniformity for Cherenkov applications.

Findings

Density increases at aerogel edges due to pin-drying.

Laser and X-ray methods effectively assess density uniformity.

Cherenkov imaging confirms suitability for particle detection.

Abstract

We present optical and X-ray radiographical characterization of silica aerogels with refractive index from 1.05 to 1.07 for a Cherenkov radiator. A novel pin-drying method enables us to produce highly transparent hydrophobic aerogels with high refractive index by shrinking wet-gels. In order to investigate the uniformity in the density (i.e., refractive index) of an individual aerogel monolith, we use the laser Fraunhofer method, an X-ray absorption technique, and Cherenkov imaging by a ring imaging Cherenkov detector in a beam test. We observed an increase in density at the edge of the aerogel tiles, produced by pin-drying.