Statistical mechanics of partially ionized stellar plasma - The Planck-Larkin partition function, polarization shifts, and simulations of optical spectra

Abstract

view Abstract Citations (122) References (40) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Statistical Mechanics of Partially Ionized Stellar Plasmas: The Planck-Larkin Partition Function, Polarization Shifts, and Simulations of Optical Spectra Dappen, Werner ; Anderson, Lawrence ; Mihalas, Dimitri Abstract We discuss a recent controversy about the Planck-Larkin partition function, and present optical simulations of high-quality spectra from laboratory hydrogen plasmas (Wiese, Kelleher, and Paquette) using several partition function formalisms. We point out that the controversy has arisen from a misunderstanding about the use of the Planck-Larkin partition function. A Planck-Larkin cancellation may still have its place in equations of state that are based on quantum-statistical many-body theory (i.e., the "physical picture"). However, experimental evidence shows that it is inconsistent to use the Planck-Larkin partition function as the internal partition function in simple models of reacting gases (i.e., the "chemical picture"). Moreover, the more sophisticated equations of state of the physical picture will have to be subjected to the same comparison with experimental data. We also address the question of plasma polarization shifts of bound-state energies. We discuss the static-screened Coulomb potential (SSCP) as an atomic potential: from theoretical considerations and observational constraints we conclude that it should not be used. The only useful result of the SSCP potential its prediction of the number of excited be obtained by alternative means, e.g., by an occupation probability formalism. Publication: The Astrophysical Journal Pub Date: August 1987 DOI: 10.1086/165446 Bibcode: 1987ApJ...319..195D Keywords: Coulomb Collisions; Partitions (Mathematics); Polarization Characteristics; Statistical Mechanics; Stellar Winds; Visible Spectrum; Atomic Interactions; Functions (Mathematics); Plasma Chemistry; Astrophysics; ATOMIC PROCESSES; PLASMAS full text sources ADS |