2-D axisymmetric line transport

Conference · Tue Nov 20 00:00:00 EST 1990

OSTI ID:6440155

Castor, J I; Dykema, P G ^[1]; Klein, R I ^[2]

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1. Lawrence Livermore National Lab., CA (USA)
2. Lawrence Livermore National Lab., CA (USA) California Univ., Berkeley, CA (USA). Dept. of Astronomy

The methods used in the ALTAIR code for computing the transfer of spectral line radiation in two-dimensional axially-symmetric geometry are described. ALTAIR uses a variable-Eddington-tensor approach, in which the transfer equation of non-coherent line scattering is written in moment form, and the moments are closed with an assumed tensor relating the monochromatic pressure tensor and energy density; this Eddington tensor is obtained self-consistently using an accurate angle-dependent solution of the transfer equation. The finite element method for solving the moment system, and the discontinuous finite element method for solving the S{sub n} equation of transfer are described. Two applications of the method are discussed: line formation in uniform cylinders with different length-diameter ratios, and monochromatic transfer on an irregular x-y mesh (the Mordant test problem). 13 refs., 2 figs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6440155
• Report Number(s): UCRL-JC-105533; CONF-9009308-2; ON: DE91005226
• Resource Relation: Conference: NATO advanced workshop on stellar atmospheres: beyond classical models, Trieste (Italy), 3-7 Sep 1990
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
RADIATION TRANSPORT
TWO-DIMENSIONAL CALCULATIONS
STELLAR ATMOSPHERES
AXIAL SYMMETRY
COMPUTER CALCULATIONS
EDDINGTON THEORY
FINITE ELEMENT METHOD
PARTIAL DIFFERENTIAL EQUATIONS
SCATTERING
ATMOSPHERES
DIFFERENTIAL EQUATIONS
EQUATIONS
NUMERICAL SOLUTION
SYMMETRY
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources
657000 - Theoretical & Mathematical Physics