J/A+A/645/A101 3D MHD models angular quadratures (Jaume Bestard+, 2021)
Improved near optimal angular quadratures for polarised radiative transfer in
3D MHD models.
Jaume Bestard J., Stepan J., Trujillo Bueno J.
<Astron. Astrophys. 645, A101 (2021)>
=2021A&A...645A.101J 2021A&A...645A.101J (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Polarization
Keywords: methods: numerical - polarisation - radiative transfer
Abstract:
Accurate angular quadratures are crucial for the numerical solution of
three-dimensional (3D) radiative transfer problems, especially when
including the spectral line polarisation produced by the scattering of
anisotropic radiation. There are two requirements for an optimal
quadrature that are difficult to satisfy simultaneously: high accuracy
and short computing time. Recently, imposing certain symmetries, we
have derived a set of near optimal angular quadratures. Here we extend
our previous investigation by considering other symmetries. Moreover,
we test the performance of our new quadratures by numerically solving
a radiative transfer problem of resonance line polarisation in a 3D
model of the solar atmosphere resulting from a magneto-hydrodynamical
simulation. The new angular quadratures derived here outperform the
previous ones in terms of the number of rays needed to achieve any
given accuracy.
Description:
The file name has the following convention:
u: quadrature for unpolarised radiation
p: quadrature for polarised radiation
lX: quadrature for the order L=X
nY: quadrature with N=Y rays in total.
All the files have the same structure.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ul2n3.dat 57 3 Unpolarised case for L=2 and N=3
ul3n4.dat 57 4 Unpolarised case for L=3 and N=4
ul4n6.dat 57 6 Unpolarised case for L=4 and N=6
ul5n8.dat 57 8 Unpolarised case for L=5 and N=8
ul6n11.dat 57 11 Unpolarised case for L=6 and N=11
ul7n12.dat 57 12 Unpolarised case for L=7 and N=12
ul8n17.dat 57 17 Unpolarised case for L=8 and N=17
ul9n20.dat 57 20 Unpolarised case for L=9 and N=20
ul10n24.dat 57 24 Unpolarised case for L=10 and N=24
ul11n26.dat 57 26 Unpolarised case for L=11 and N=26
ul12n33.dat 57 33 Unpolarised case for L=12 and N=33
ul13n39.dat 57 39 Unpolarised case for L=13 and N=39
ul14n44.dat 57 44 Unpolarised case for L=14 and N=44
ul15n45.dat 57 45 Unpolarised case for L=15 and N=45
pl2n14.dat 57 14 Polarised case for L=2 and N=14
pl3n20.dat 57 20 Polarised case for L=3 and N=20
pl4n24.dat 57 24 Polarised case for L=4 and N=24
pl5n30.dat 57 30 Polarised case for L=5 and N=30
pl6n38.dat 57 38 Polarised case for L=6 and N=38
pl7n44.dat 57 44 Polarised case for L=7 and N=44
pl8n53.dat 57 53 Polarised case for L=8 and N=53
pl9n62.dat 57 62 Polarised case for L=9 and N=62
pl10n72.dat 57 72 Polarised case for L=10 and N=72
pl11n78.dat 57 78 Polarised case for L=11 and N=78
pl12n93.dat 57 93 Polarised case for L=12 and N=93
pl13n100.dat 57 100 Polarised case for L=13 and N=100
pl14n117.dat 57 117 Polarised case for L=14 and N=117
pl15n124.dat 57 124 Polarised case for L=15 and N=124
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Byte-by-byte Description of file: *.dat
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Bytes Format Units Label Explanations
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1- 17 F17.15 --- weight Normalized weights over the whole sphere
19- 37 F19.15 deg incl Inclination measured from the positive Z-axis
39- 57 F19.15 deg azim Azimuth measured from the positive X-axis
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Acknowledgements:
Jaume Jaume Bestard, jjaumeb(at)iac.es
(End) Patricia Vannier [CDS] 25-Nov-2020