Moderator gratings for the generation of epithermal positive muons
| Autor: | A. Hofer, Christian David, Thomas Prokscha, Elvezio Morenzoni, L. Scandella, H Glückler |
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| Rok vydání: | 2001 |
| Předmět: |
Physics
Muon business.industry Isotropy General Physics and Astronomy Surfaces and Interfaces General Chemistry Substrate (electronics) Grating Condensed Matter Physics Molecular physics Surfaces Coatings and Films Optics Reflection coefficient business Absorption (electromagnetic radiation) Layer (electronics) FOIL method |
| Zdroj: | Applied Surface Science. 172:235-244 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/s0169-4332(00)00857-6 |
| Popis: | We studied the effect of surface enlargement on the efficiency of a muon (μ+) moderator by comparing the flux of epithermal μ+ emerging from a solid Ar (s-Ar) layer deposited on a flat Al substrate with the fluxes from an Ar layer deposited on gratings manufactured in Si and Ag substrates. We developed a simple replication technique to emboss a Si grating into a thin Ag foil, where the gratings consist of V-shaped grooves with 20 μm depth and ridge distance of 30 μm on an area of 30×30 mm 2 . We obtain a gain in epithermal μ+ flux of 1.5 with respect to that of a flat moderator geometry. The 15% reduction with respect to the geometrical enlargement factor of 1.73 is due to μ+ absorption losses in the V-groove walls. The data imply a nearly isotropic angular distribution of epithermal μ+ inside the s-Ar moderator and a reflection coefficient of about 80% for epithermal μ+ impinging on s-Ar. |
| Databáze: | OpenAIRE |
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