1D test code: Files in folder "1D" will run grey body model if "Makefile" is made and run using command "./MAIN", along with the Villa current profile. To run P1 approximation the files from "NEC_or_P1" replace their equivalents currently in the main folder and rerun the Makefile. The NEC approximation uses the same file, uncomment the indicated lines, and comment out the P1 approximation. The relevant files for SP-3 approximation are in folder "SP3". The grey body model uses the file "mixtureFull19.txt", the other models use "P1ApproxEoS.txt" found in folder "NEC_or_P1".

The file "mixtureFull19.txt" was received from Frederik Träuble and contains the e and rho values used to calculate his EoS. The full EoS can be obtained on application to the authors of “An improved equation of state for air plasma simulations,” Physics of Fluids 33, 036112 (2021) F. Träuble, S. Millmore, and N. Nikiforakis. P1ApproxEoS add the columns for the band averaged absorption coefficients but the code has been submitted in the form that it need the missing lines, which would need to be obtained from the full EoS.

2D test code: The radiative source files are in their labelled folders, PoissonSolutions contains a sample code to pre-compute the magnetic field and current density for a 2D lightning arc with electrode for the ARP standard component D current profile

Absorption Coefficient and band averages for P1/SP3 approximations: There are a number of text files containing data for the absorption coefficient taken from the sources listed in the paper:

*MolecularNitrogen, MolecularOxygen: Kivel, "Bremsstrahlung in air"
*NIIPartition,NIlines,Nitrogen,NIPartition,OIIPartition,OIlines,OIPartition,Oxygen: Martins, "Etude expérimentale et théorique d’un arc de foudre et son interaction avec un matériau aéronautique", NIST database, Konjevic, "Experimental Stark Widths and Shifts for Spectral Lines of Neutral and Ionized Atoms" "Experimental Stark widths

and shifts for spectral lines of neutral and ionized atoms (a critical review of selected data for the period 1989 through 2000)" "Experimental Stark widths and shifts for spectral lines of neutral atoms (a critical review of selected data for the period 1976 to 1982)" *NOMolBands,NOPartitionFunction1,O2Molbands,O2PartitionFunction,N2Molbands,N2PartitionFunction: HITRAN database *PhotoAbsN2, PhotoAbsO2: Chauveau, "Radiative transfer in LTE air plasmas for temperatures up to 15; 000 K" *PhotodetachmentO2Chauveau: Chauveau, "Radiative transfer in LTE air plasmas for temperatures up to 15; 000 K" *PhotoionisationN, Photoionisation2Nnew, PhotoionisationO, Photoionisation2Onew, PhotoionisationNplus, Photoionisation2Nplusnew, PhotoionisationOplus, Photoionisation2Oplusnew: TOPBASE database *PhotoIonN2lambda, PhotoIonO2lambda: Fenelly, "Photoionization and photoabsorption cross sections of O, N2, O2, and N for aeronomic calculations" *SchumanRunge: Churchill "Absorption coefficients of heated air: a tabulation to 24 000 K"

All data accessed June-July 2018

Makefile runs:"Band Averages.C", "BoundBound.C", "BoundFree.C", "FreeFree.C", "LineProperties.C", "KappaTotal.C", "MolecularBands.C" and uses accompanying ".h" files and "Constants.h".  It reads in from "mixtureFull19.txt" (again the reduced version is submitted here) and writes to "NECeos.txt" and "P1ApproxEoS.txt".  The last column of NEC EoS is the NEC, the other columns are from "mixtureFull19.txt".  The last 10 columns of "P1ApproxEoS.txt" are the band averaged values required for the P1 and SP3 approximations, alternating $K_{\nu}$ and $K_{\nu}B_{\nu}$.