Positron annihilation on large molecules
نویسندگان
چکیده
منابع مشابه
Mechanisms of positron annihilation on molecules
The aim of this work is to identify the mechanisms responsible for very large rates and other peculiarities observed in low-energy positron annihilation on molecules. The two mechanisms considered are: (i) Direct annihilation of the incoming positron with one of the molecular electrons. This mechanism dominates for atoms and small molecules. I show that its contribution to the annihilation rate...
متن کاملPositron Annihilation on Atoms and Molecules
OF THE DISSERTATION Positron Annihilation on Atoms and Molecules
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Measurements of positron-on-molecule annihilation have established that positrons attach to a variety of molecules via vibrational Feshbach resonances VFRs . These resonances, in turn, result in greatly enhanced positron annihilation rates beyond those expected in simple collisions. A recent paper J. A. Young and C. M. Surko, Phys. Rev. Lett. 99, 133201 2007 described experimental studies and a...
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Vibrational Feshbach resonances are dominant features of positron annihilation for incident positron energies in the range of the molecular vibrations. Studies in relatively small molecules are described that elucidate the role of intramolecular vibrational energy redistribution into near-resonant multimode states, and the subsequent coupling of these modes to the positron continuum, in suppres...
متن کاملg-ray spectra from positron annihilation on atoms and molecules
Positron annihilation on a wide variety of atoms and molecules is studied. Room-temperature positrons confined in a Penning trap are allowed to interact with molecules in the form of low-pressure gases so that the interaction is restricted to binary encounters between a positron and a molecule. Data are presented for the g-ray spectra resulting from positrons annihilating in such interactions. ...
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ژورنال
عنوان ژورنال: Physical Review A
سال: 2000
ISSN: 1050-2947,1094-1622
DOI: 10.1103/physreva.61.022719