Abstract
We report on muonium (Mu) emission into vacuum following implantation in mesoporous thin films. We obtain a yield of Mu into vacuum of at 250 K and at 100 K for 5 keV implantation energy. From the implantation energy dependence of the Mu vacuum yield we determine the Mu diffusion constants in these films: and . Describing the diffusion process as quantum mechanical tunneling from pore to pore, we reproduce the measured temperature dependence of the diffusion constant. We extract a potential barrier of which is consistent with our computed Mu work function in of . The high Mu vacuum yield, even at low temperatures, represents an important step toward next generation Mu spectroscopy experiments.
- Received 23 December 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.143401
© 2012 American Physical Society