کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10675778 | 1010730 | 2005 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Positron scattering in helium: Virtual-positronium resonances
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سطوح، پوششها و فیلمها
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چکیده انگلیسی
Total cross sections for positron scattering in helium and argon were measured at 0.5-25Â eV with a new spectrometer from Trento University, with a good angular resolution (3.1Â ÃÂ 10â4Â sr). Data in argon fall in-between earlier measurements; those for He agree well with the previous above the positronium formation thresholds but are up to 50% higher at low energies. Data for He show four resonant-like structures, one at the positronium threshold formation (17.8Â eV) predicted by Van Reeth and Humberston [J. Phys. B 32 (1999) L103], another at about 6.8Â eV and two very prominent centred at 1.6Â eV and 2.2Â eV. Following Gribakin and King [J. Phys. B 27 (1994) 2639] the two latter could be signs of virtual-positronium formation in helium.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 240, Issue 3, November 2005, Pages 666-674
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 240, Issue 3, November 2005, Pages 666-674
نویسندگان
G.P. Karwasz, D. Pliszka, A. Zecca, R.S. Brusa,