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Effective resonant formation of 20 Ne in stars
Author(s) -
Md. Khairozzaman A. E.
Publication year - 1986
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.2113070404
Subject(s) - stars , physics , excited state , astrophysics , helium , reaction rate , atomic physics , giant star , chemistry , biochemistry , catalysis
The resonant reaction rates of 16 O(α, γ) 20 Ne have been determined for the 5.64(3 ‐ ) MeV 5.8(1 ‐ ) MeV excited states of 20 Ne under strong screening conditions utilizing the temperature‐density plots of the helium plasma after I TOH et al. (1977). The screened reaction rates were found to be many times greater than the unscreened ones. It has been found that the most effective resonant formation of 20 Ne takes place at density 10 8 g cm ‐3 . As the density increases beyond 10 8 g cm ‐3 with corresponding rise of temperature the screened reaction rates (i. e. effective reaction rates) decrease. Such a decrease affects the presupernova yields from massive stars drastically The giant and dwarf stage of stellar evolution under pycnonuclear density conditions (10 8 ‐‐10 9 g cm ‐3 ) will be retarded beyond the density of 10 8 g cm ‐3 in stellar interiors.