•Ivo Rolf Seitenzahl

•Graduate Student in Physics

•Advisor: Jim Truran

Nuclear Statistical Equilibrium (NSE)

for type

1a supernova si

mulations

Road map

•NSE equations

•Plots, plots and more plots (results)

•Applications to type 1a supernovae

Equilibrium equations

Method of solving

Substitute

into the conservation equations:

1)

2)

Solve with Newton-Raphson method numerically for the chemical potentials of neutrons and protons. Substitute

back to get NSE massfractions of the nuclei as a function of temperature, density and electron fraction.

Derived quantities

Basic Picture

Effects of excited states and coulomb

interaction

Effect of neutronization

Supernova connection

• Timescale to reach NSE is less than dynamic timescale for a large portion of the early explosion (allows us to treat ashes as NSE)

• Heat capacity of the ion gas depends on , which in NSE is a function of

• Weak interactions are energy sink

• Light curve sensitive to amount of produced, which depends in NSE sensitively on

Conclusions

•Exited states and Coulomb corrections to ideal gas must be included to compute massfractions

•Inclusion of weak interactions probably important for type 1 a supernova dynamics

•Include neutronization rates and energy loss in simulations at the ASCI Flash Center in Chicago