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Diffuse galactic annihilation radiation from supernova nucleosynthesisThe propagation of MeV positrons in the outer ejecta of type I supernovae was investigated. It was found that the positrons created at times of approx 100 days propagated along magnetic field lines in the outer ejecta without any appreciable pitch-angle scattering or excitation of hydromagnetic waves. The lack of significant pitch-angle scattering is well consistent with models of wave excitation and scattering by resonant interactions. This occurs because time periods to scatter the particles or to excite waves are significantly longer than escape times. Thus it is expected that, when positrons are not coupled to the ejecta by Coulomb collisions, they escape from the relatively cold, dense ejecta and reside predominantly in the tenuous, hotter, shock-heated interstellar gas. In the tenuous shock-heated gas the positron lifetime against annihilation is much greater than lifetimes in the dense ejectra. Thus the production of steady-state diffuse annihilation radiation by some fraction of these escaped positrons seems probable.
Document ID
19850025691
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Higdon, J. C.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
August 12, 2013
Publication Date
August 1, 1985
Publication Information
Publication: 19th Intern. Cosmic Ray Conf - Vol. 1
Subject Category
Space Radiation
Report/Patent Number
OG-3.2-8
Report Number: OG-3.2-8
Accession Number
85N34004
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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