The heavy element synthesis induced by the large neutron fluxes released by the reaction (C13)(alpha, n)(O-16) in low mass planetary nebulas progenitors experiencing thermal pulses is examined. The mechanism of semiconvection proposed by Iben and Renzini (1982) for the formation of the initial (C-13) is assumed to be effective. A new reaction network has been created, incorporating updated values for the cross-sections of alpha-, p- and n-captures on 350 nuclei and including 80 branching points along the neutron capture path. As a preliminary investigation 14 thermal pulses were followed. The results of the computations and their relevance in explaining the formation of the heavy n-rich elements are briefly discussed.
The 's' process nucleosynthesis in low mass stars and the neutron source (C-13)(alpha, n)(O-16)
BUSSO, Maurizio Maria;
1988
Abstract
The heavy element synthesis induced by the large neutron fluxes released by the reaction (C13)(alpha, n)(O-16) in low mass planetary nebulas progenitors experiencing thermal pulses is examined. The mechanism of semiconvection proposed by Iben and Renzini (1982) for the formation of the initial (C-13) is assumed to be effective. A new reaction network has been created, incorporating updated values for the cross-sections of alpha-, p- and n-captures on 350 nuclei and including 80 branching points along the neutron capture path. As a preliminary investigation 14 thermal pulses were followed. The results of the computations and their relevance in explaining the formation of the heavy n-rich elements are briefly discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
