Progress in development of silica aerogel for particle- and nuclear-physics experiments at J-PARC

TL;DR

This paper reports advancements in hydrophobic silica aerogel production, enabling a range of refractive indices and larger sizes, to support upcoming particle and nuclear physics experiments at J-PARC.

Contribution

It introduces optimized production methods for silica aerogels with varied indices and larger sizes, including a new pin drying technique for ultrahigh refractive index aerogels.

Findings

Successful production of aerogels with refractive indices 1.03-1.04 and 1.075-1.08

Development of a pin drying method for ultrahigh index aerogels (>1.10)

Fabrication of low-density aerogels for muonium emission

Abstract

This study presents the advancement in hydrophobic silica aerogel development for use as Cherenkov radiators and muonium production targets. These devices are scheduled for use in several particle- and nuclear-physics experiments that are planned in the near future at the Japan Proton Accelerator Research Complex. Our conventional method to produce aerogel tiles with an intermediate index of refraction of approximately 1.05 is extended so that we can now produce aerogel tiles with lower indices of refraction (i.e., 1.03-1.04) and higher indices of refraction (i.e., 1.075-1.08); each with excellent transparency. A new production method, called pin drying, was optimized to produce larger area aerogels consistently with an ultrahigh index of refraction (>1.10). In addition, for use as a thermal-muonium-emitting material at room temperature, dedicated low-density aerogels were fabricated using the conventional method.