marchetti_2007

S. Marchetti and R. Simili, Infrared Phys. Technol. 50, 78 (2007)

Source record · Catalogue · Review register

DOI: 10.1016/j.infrared.2006.07.003

Source kind: measurement

Recorded technique: The differential two-Fabry-Perot technique of marchetti_2006 with a tunable single-mode RF-excited CO2 laser (400 mbar mixture, 700 uJ, 3 us pulses at 1 kHz) on 27 lines of the 9 and 10 um bands; 209 cm gas cell; residual thermal drift (0.35 fringes per degree C) removed; ‘our measurement limit is the accuracy of our pressure measurement (0.4%)’ (p. 79).

Materials in structured entries: CO2

Dataset quantities: refractivity

Contents: 1 dataset; 1 formula.

Curation notes

Values are the pressure coefficient dn with n = 1 + dn P (Eq. 1), in 1e-4 per atm, at ‘T = 21°’ (21 degrees C); the paper converts other data to 21 degrees C ‘following the gas perfect relation’ (Eq. 3), so each value is taken as the refractivity at 1 atm, 294.15 K with the ideal-gas density. The per-line errors (last digits, 0.3-0.7 %) are of unstated level and presumably include the 0.4 % pressure accuracy, which is common to all lines (not separated). Frequencies are vacuum wavenumbers in cm^-1.

Consistency: marchetti_2006’s CO2 value at 10.57 um (946 cm^-1), 4.087 at 23 degrees C, scaled to 21 degrees C by T (296.15/294.15) is 4.115, against 4.114 (12) here at 1P18 (946 cm^-1). The conclusion (p. 80) calls Simmons’s 10.59 um value ‘5% overestimated’.

Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets

marchetti_2007/experiment_CO2

{
  "id": "experiment_CO2",
  "material": "CO2",
  "file": "CO2/marchetti_2007__experiment_CO2.csv",
  "table": "tbl_33adeac1f5b0",
  "quantity": "refractivity",
  "scale": 0.0001,
  "abscissa_unit": "cm-1",
  "wavelength_medium": "vacuum",
  "state": {
    "pressure_atm": 1,
    "temperature_c": 21
  },
  "density": "ideal",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  }
}

The table’s 27 lines; row ids are the line labels as printed (1R.., 1P.. are the 10-um-band lines, usually written 10R.., 10P..).

Formulas

marchetti_2007/eq4

{
  "id": "eq4",
  "material": "CO2",
  "equation": "Eq. (4), p. 80",
  "printed": "dn(v) = -0.2404 + 7.8801E-3 v - 3.454E-6 v^2",
  "variable": "v: vacuum wavenumber in cm^-1; dn in 1e-4 per atm at 21 degrees C",
  "state": "{ pressure_atm = 1, temperature_c = 21 } (dn times 1 atm)",
  "density": "ideal",
  "range": "931-1083.5 cm^-1 ('valid only in the 10 um region')",
  "coefficients": {
    "a0": "-0.2404",
    "a1": "7.8801e-3",
    "a2": "-3.454e-6"
  },
  "check": "Reproduces the 27 tabulated values with residuals within their stated errors (largest 0.021 at 1P16 against an error of 0.020). Checked 2026-09-24."
}

A parabola fitted to the table, not a physical dispersion model.

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.