CR: Stellar Models with Monte Carlo Reactions Rates

Project: Research project

Description

This proposal builds on a completely new method of estimating experimental thermonuclear reaction rates and their uncertainties. These reaction rates are calculated using a Monte Carlo method that uses physically motivated probability densities for each experimental nuclear physics quantity that enters in the rate calculation. Unlike all previously reported reaction rates that lack a rigorous statistical meaning, the new results provide the experimen- tal reaction rate probability density at any given temperature. From this rate distribution, recommended, low and high reaction rates are derived for any desirable coverage probability in a straightforward manner. We propose to use the 66 nuclear reactions on A=14-40 target nuclei, for which Monte Carlo rates are now available, as a backbone for construction of a next-generation library of thermonuclear reaction rates, and to employ this new kind of library for simulating the evolution of massive stars and classical novae. We will use the Monte Carlo reaction rate library in a systematic survey of pre-supernova and classical nova evolution in order to compare our calculations with existing observations and predict new observable signatures for both ground based and satellite data. We will use two existing and robust one-dimensional, implicit, stellar evolution codes to verify and validate our resulting evolutionary sequences. We will apply three dierent strategies to our studies. First, generate \N" realizations of the reaction rates and compute \N" stellar tracks; second, post-process the temperature-density-time stellar histories with our nuclear reaction network and the Monte Carlo rates; and, third, Monte Carlo sample the reaction rates independently for each zone in the stellar model. We will quantify and report on which method gives the most defensible results.@
StatusFinished
Effective start/end date10/1/109/30/14

Funding

  • National Science Foundation (NSF): $330,114.00

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stellar models
reaction kinetics
thermonuclear reactions
nuclear reactions
novae
stellar evolution
nuclear physics
massive stars
Monte Carlo method
supernovae
proposals
estimating
signatures
histories
nuclei
temperature