Muonium Emission into Vacuum from Mesoporous Thin Films at Cryogenic Temperatures
| Autor: | K. S. Khaw, Bernardo Barbiellini, K. Kwuida, Laszlo Liszkay, Paolo Crivelli, Thomas Prokscha, Zaher Salman, Klaus Kirch, Aldo Antognini, Elvezio Morenzoni, Florian M. Piegsa, Andreas Suter |
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| Rok vydání: | 2012 |
| Předmět: |
Physics
Atomic Physics (physics.atom-ph) 010308 nuclear & particles physics Muonium FOS: Physical sciences General Physics and Astronomy 01 natural sciences Physics - Atomic Physics High Energy Physics - Experiment 3. Good health High Energy Physics - Experiment (hep-ex) 0103 physical sciences Thin film Atomic physics 010306 general physics Energy (signal processing) |
| Zdroj: | Physical Review Letters. 108 |
| ISSN: | 1079-7114 0031-9007 |
| Popis: | We report on Muonium (Mu) emission into vacuum following {\mu}+ implantation in mesoporous thin SiO2 films. We obtain a yield of Mu into vacuum of (38\pm4)% at 250 K temperature and (20\pm4)% at 100 K for 5 keV {\mu}+ implantation energy. From the implantation energy dependence of the Mu vacuum yield we determine the Mu diffusion constants in these films: D250KMu = (1.6 \pm 0.1) \times 10-4 cm2/s and D100KMu = (4.2\pm0.5)\times10-5 cm2/s. Describing the diffusion process as quantum mechanical tunneling from pore-to-pore, we reproduce the measured temperature dependence T^3/2 of the diffusion constant. We extract a potential barrier of (-0.3 \pm 0.1) eV which is consistent with our computed Mu work-function in SiO2 of [-0.3,-0.9] eV. The high Mu vacuum yield even at low temperatures represents an important step towards next generation Mu spectroscopy experiments. Comment: 5 pages, 5 Figures |
| Databáze: | OpenAIRE |
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