Computer Science – Numerical Analysis
Scientific paper
Nov 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005phdt.........6l&link_type=abstract
Ph.D dissertation, 2005. 200 pages; United States -- California: University of Southern California; 2005. Publication Number: A
Computer Science
Numerical Analysis
Equation Of State, Partially Ionized Plasmas, Solar Interior, Planck-Larkin Partition
Scientific paper
The three major material properties relevant for solar and stellar modeling are the equation of state (EOS), opacity and the nuclear reaction rate. Due to the nature of the equations of stellar structure and evolution, in most parts of a stars interior, the three material properties are entangled, and it is difficult to use astrophysics to constrain a single one.
Luckily, thanks to the adiabatic stratification of the convection zone, there the structure only depends on the EOS, which is therefore largely disentangled from the other quantities. Our research, which aims at constraining the EOS using information from the Sun, is therefore most successful when data from the convection zone are used.
Among the many solar equations of state that are being currently used there are two popular ones: Mihalas-Däppen-Hummer (MHD) EOS and OPAL EOS. Helioseismic inversion procedures, which have become standard to evaluate the accuracy of different solar models with respect to the real Sun, have revealed that except for the top 2%, the OPAL EOS matches the solar observations better than the MHD EOS. For this reason we have set our research goal to find a modification of the MHD EOS that can, in a first step, simulate the OPAL EOS, and ultimately, the real Sun.
This goal has been attained. By construction, the OPAL EOS contains higher order correlation terms which are missing in the MHD EOS. Through an inversion procedure from the activity series expansion (ACTEX), upon which the OPAL EOS is based to the free energy expression of the MHD EOS, we have found out that the free particle assumption, used in the original version of the MHD EOS has indeed to be abandoned. We show that the two-body scattering terms of the Coulomb interaction, as well as electron degeneracy play a significant role in the difference between the original version of the MHD and OPAL EOS.
During our interdisciplinary investigation, aiming at seeking an improved MHD EOS under the guidance of the OPAL EOS, we have performed a thorough systematic theoretical and numerical analysis, particularly on applicability of the static screened Coulomb potential (SSCP) as an intra-atomic potential and the physical meaning of the Planck-Larkin partition function (PLPF). We thereby clarified some misunderstandings and confusions. In particular, we have addressed the density dependence of the Planck-Larkin partition function, an issue that has been debated for more than 30 years.
No associations
LandOfFree
Improvements in the equation of state for the partially ionized plasmas of the solar interior does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Improvements in the equation of state for the partially ionized plasmas of the solar interior, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Improvements in the equation of state for the partially ionized plasmas of the solar interior will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1652402