X-ray radiographic technique for measuring density uniformity of silica aerogel

TL;DR

This paper introduces a novel X-ray radiographic method to accurately measure the density uniformity of silica aerogels, crucial for their performance in Cherenkov detectors, demonstrating its effectiveness on different aerogel samples.

Contribution

A new X-ray radiographic technique for quantitatively assessing silica aerogel density uniformity, suitable for large-area detector applications.

Findings

The technique successfully measured density uniformity within ±1%.

It confirmed the uniformity of original and Panasonic aerogels.

The method is effective for quality control of aerogel production.

Abstract

This paper proposes a new X-ray radiographic technique for measuring density uniformity of silica aerogels used as radiator in proximity-focusing ring-imaging Cherenkov detectors. To obtain high performance in a large-area detector, a key characteristic of radiator is the density (i.e. refractive index) uniformity of an individual aerogel monolith. At a refractive index of n = 1.05, our requirement for the refractive index uniformity in the transverse plane direction of an aerogel tile is |\delta (n - 1)/(n - 1)| < 4% in a focusing dual layer radiator (with different refractive indices) scheme. We applied the radiographic technique to evaluate the density uniformity of our original aerogels from a trial production and that of Panasonic products (SP-50) as a reference, and to confirm they have sufficient density uniformity within \pm 1% along the transverse plane direction. The measurement results show that the proposed technique can quantitatively estimate the density uniformity of aerogels.