Enhancement of direct positron annihilation due to temporal capture by an atom
Journal Article
·
· Physical Review. A
- RIKEN - of Physical and Chemical Research, Wako, Saitama 351-0198 (Japan)
We investigate direct positron annihilation during a collision in a gas; this is physically separable from indirect annihilation, i.e., via formation of positronium (Ps) and its decay. The cross section of direct annihilation is calculated from the evolution of a wave packet with a time width much shorter than the Ps lifetime, where the direct contribution is extracted through the time dependence of the survival probability. The cross section obtained for a hydrogen atom is found to be enhanced in energies around 10 eV well above the Ps formation threshold. This enhancement is shown to be due to temporal positron capture with electronic excitation in the atom.
- OSTI ID:
- 20636388
- Journal Information:
- Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 67; ISSN 1050-2947; ISSN PLRAAN
- Country of Publication:
- United States
- Language:
- English
Similar Records
Inseparable positron annihilation and positronium formation in positron-atom collisions: Description in terms of an absorption potential
Effect of a finite-energy spread of the positron beam on the threshold behavior of the positron annihilation cross section
Direct-annihilation fraction of positrons in a neutral low-density galactic environment
Journal Article
·
Wed Oct 01 00:00:00 EDT 2003
· Physical Review. A
·
OSTI ID:20640342
Effect of a finite-energy spread of the positron beam on the threshold behavior of the positron annihilation cross section
Journal Article
·
Sat Nov 30 23:00:00 EST 2002
· Physical Review. A
·
OSTI ID:20632505
Direct-annihilation fraction of positrons in a neutral low-density galactic environment
Journal Article
·
Mon Mar 31 23:00:00 EST 1986
· Phys. Rev. A; (United States)
·
OSTI ID:6054804