Measurement of Muonium Emission from Silica Aerogel
/ Authors
P. Bakule, G. Beer, D. Contreras, M. Esashi, Y. Fujiwara, Y. Fukao, S. Hirota, H. Iinuma, K. Ishida, M. Iwasaki
and 21 more authors
T. Kakurai, S. Kanda, H. Kawai, N. Kawamura, G. Marshall, H. Masuda, Y. Matsuda, T. Mibe, Y. Miyake, S. Okada, K. Olchanski, A. Olin, H. Onishi, N. Saito, K. Shimomura, P. Strasser, M. Tabata, D. Tomono, K. Ueno, K. Yokoyama, S. Yoshida
/ Abstract
Emission of muonium ($\mu^{+}e^{-}$) atoms from silica aerogel into vacuum was observed. Characteristics of muonium emission were established from silica aerogel samples with densities in the range from 29 mg cm$^{-3}$ to 178 mg cm$^{-3}$. Spectra of muonium decay times correlated with distances from the aerogel surfaces, which are sensitive to the speed distributions, follow general features expected from a diffusion process, while small deviations from a simple room-temperature thermal diffusion model are identified. The parameters of the diffusion process are deduced from the observed yields.
DOI: 10.1093/ptep/ptt080