luna_physdata

Luna.jl, src/PhysData.jl (https://github.com/LupoLab/Luna.jl), branch modal-fixed and PR #425

Source record · Catalogue · Review register

No DOI is recorded.

Source kind: fit

Recorded technique: Dispersion formulas used by Luna that have no publication of their own.

Materials in structured entries: Ar, He, Kr

Dataset quantities: None recorded.

Contents: 0 datasets; 4 formulas.

Curation notes

Legacy models, kept to compare Luna’s and solprop’s choices with the data. Luna evaluates every Sellmeier gamma as n^2 - 1 at 0 degrees C and 1 bar divided by the real-gas density there (dens_1bar_0degC), whatever state the source used (LB-106 to LB-108 in solprop’s LUNABUGS.md); the entries here keep Luna’s own reference state.

The argon fit (Luna commit 56cc3ab, C. Brahms, 2025-10-02, ‘improved argon ref index’) and the krypton fit (PR #425, T. Grigorova) are three-term fits of the same form as Ermolov’s helium formula to Kingston’s (1964) vacuum-ultraviolet values joined to Borzsonyi et al.’s (2008) visible and near-infrared formula; their construction is described only in PR #425’s notebook. solprop found the krypton fit’s ratio to Borzsonyi to be the 1 atm / 1 bar density ratio and so references it to 1 atm; both readings are recorded.

Datasets

No datasets are recorded.

Formulas

luna_physdata/jct_He

{
  "id": "jct_He",
  "material": "He",
  "equation": "PhysData.jl, sellmeier_gas(:He), gamma_JCT",
  "printed": "B1 2.16463842e-05, C1 -6.80769781e-04, B2 2.10561127e-07, C2 5.13251289e-03, B3 4.75092720e-05, C3 3.18621354e-03",
  "variable": "lambda: wavelength in um",
  "form": "n2_sellmeier",
  "terms": {
    "B": [
      "2.16463842e-05",
      "2.10561127e-07",
      "4.75092720e-05"
    ],
    "C": [
      "-6.80769781e-04",
      "5.13251289e-03",
      "3.18621354e-03"
    ]
  },
  "state": "1bar_0C",
  "density": "real",
  "range_nm": [
    90.0,
    1000.0
  ],
  "kind": "legacy"
}

Ermolov et al. (2015) with the coefficients to more digits; Luna’s default helium.

luna_physdata/kingston_fit_Ar

{
  "id": "kingston_fit_Ar",
  "material": "Ar",
  "equation": "PhysData.jl, sellmeier_gas(:Ar), gamma_JCT, commit 56cc3ab",
  "printed": "B1 0.00032323117217767093, C1 0.0045416501944977915, B2 0.00011557814904827939, C2 0.011120847461156543, B3 0.00010909808164540697, C3 0.0006827046691889898",
  "variable": "lambda: wavelength in um",
  "form": "n2_sellmeier",
  "terms": {
    "B": [
      "0.00032323117217767093",
      "0.00011557814904827939",
      "0.00010909808164540697"
    ],
    "C": [
      "0.0045416501944977915",
      "0.011120847461156543",
      "0.0006827046691889898"
    ]
  },
  "state": "1bar_0C",
  "density": "real",
  "range_nm": [
    110.0,
    1000.0
  ],
  "kind": "legacy"
}

Luna’s default argon since 56cc3ab; solprop’s ‘kingston’ argon source. 110 nm is PR #425’s phase-matching limit for argon.

luna_physdata/kingston_fit_Kr_1bar

{
  "id": "kingston_fit_Kr_1bar",
  "material": "Kr",
  "equation": "PR #425, sellmeier_gas(:Kr), gamma_JCT",
  "printed": "B1 7.156207185088921e-6, C1 0.016126479267946525, B2 0.00023020614937540427, C2 0.01348822574907029, B3 0.000604323109684193, C3 0.004204161467601559",
  "variable": "lambda: wavelength in um",
  "form": "n2_sellmeier",
  "terms": {
    "B": [
      "7.156207185088921e-6",
      "0.00023020614937540427",
      "0.000604323109684193"
    ],
    "C": [
      "0.016126479267946525",
      "0.01348822574907029",
      "0.004204161467601559"
    ]
  },
  "state": "1bar_0C",
  "density": "real",
  "range_nm": [
    130.0,
    1000.0
  ],
  "kind": "legacy"
}

As Luna PR #425 evaluates it (divided by the 1 bar density).

luna_physdata/kingston_fit_Kr_1atm

{
  "id": "kingston_fit_Kr_1atm",
  "material": "Kr",
  "equation": "PR #425, sellmeier_gas(:Kr), gamma_JCT, referenced to 1 atm",
  "printed": "as kingston_fit_Kr_1bar",
  "variable": "lambda: wavelength in um",
  "form": "n2_sellmeier",
  "terms": {
    "B": [
      "7.156207185088921e-6",
      "0.00023020614937540427",
      "0.000604323109684193"
    ],
    "C": [
      "0.016126479267946525",
      "0.01348822574907029",
      "0.004204161467601559"
    ]
  },
  "state": "1atm_0C",
  "density": "real",
  "range_nm": [
    130.0,
    1000.0
  ],
  "kind": "legacy"
}

solprop’s reading (sellmeier.py): the fit’s ratio to Borzsonyi is 1.01307-1.01343, the 1 atm / 1 bar density ratio.

Corrections

No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.