inn_1953

E. C. Y. Inn, K. Watanabe and M. Zelikoff, “Absorption coefficients of gases in the vacuum ultraviolet. Part III. CO2”, J. Chem. Phys. 21, 1648 (1953)

Source record · Catalogue · Review register

DOI: 10.1063/1.1698637

Source kind: measurement

Recorded technique: Photoelectric absorption as in Watanabe et al. (1953, watanabe_1953): windowless hydrogen discharge, 1 m grating vacuum monochromator (band width about 0.85 A; two gratings, one of somewhat higher resolution, agreeing within experimental error), a 47 mm cell with LiF windows, a sodium-salicylate-coated 1P21 photomultiplier, scanned at 20 A/min; CO2 purified by repeated sublimation (impurities under 1 part in 2000) at 0.002-100 mm Hg, k averaged over several pressures; 1060-1800 A (pp. 1648-1649).

Materials in structured entries: CO2

Dataset quantities: absorption_cross_section, oscillator_strength

Contents: 3 datasets; 0 formulas.

Curation notes

Journal pages 1648-1650 = PDF pages 2-4 (page 1 is the publisher’s cover). CO2 only. The absorption coefficients are given only in Figs. 1-3 (1060-1800 A); no table of k (Table 1 lists dissociation energies of CO + O product states, not optical data). What the text states is recorded as points.

Quantity: ‘I = I0 exp(-kx) ... x the layer thickness of the gas reduced to NTP’ (p. 1648-1649), NTP not defined further (taken as 0 C and 1 atm, as in watanabe_1953). No conversion to cross sections is given; the datasets store k with scale = 1e18 / n0, n0 = 101325 Pa / (k_B 273.15 K) = 2.6867801e19 cm^-3 (ideal gas), to the cross section in Mb; ‘photoionization_cross_section’ for want of a photoabsorption cross section (all below the CO2 ionisation limit, 13.73 eV as quoted p. 1650; format need reported). Uncertainty not stated.

Text (pp. 1648-1650): three continua with maxima at about 1475, 1332 and 1121 A and possibly a fourth below 1100 A, all overlaid by diffuse bands; the 1475 A continuum’s long-wavelength limit about 1818 A (6.8 eV). Wilkinson and Johnston’s k (1440-1670 A, dashed in Fig. 1) refer to 30 C and atmospheric pressure (‘at NTP their values should be increased by about 10 percent’); their maximum is at 1495 A, and their f = 0.004 (reproduced, not extracted). Preston’s k at Lyman alpha, 2.01 cm^-1 (reproduced, not extracted). Mulliken’s assignments and the dissociation limits (Table 1: 6.8, 7.7, 10.3 eV upper limits) are not optical data.

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

Datasets

inn_1953/lyman_alpha

{
  "id": "lyman_alpha",
  "material": "CO2",
  "table": "text",
  "quantity": "absorption_cross_section",
  "unit": "Mb",
  "scale": 0.03721927208,
  "abscissa_unit": "angstrom",
  "wavelength_medium": "vacuum",
  "use": "primary"
}

1 inline points in the source record.

p. 1649: ‘at Lyman alpha (1216A) k = 1.97 cm^-1. This compares very favorably with Preston’s value of 2.01 cm^-1’. On the short-wavelength tail of the 1332 A continuum. scale = 1e18 / n0 to Mb. Wavelength as printed (1216 A, rounded). Uncertainty not stated.

inn_1953/band_peak_1119

{
  "id": "band_peak_1119",
  "material": "CO2",
  "table": "text",
  "quantity": "absorption_cross_section",
  "unit": "Mb",
  "scale": 0.03721927208,
  "abscissa_unit": "angstrom",
  "wavelength_medium": "vacuum",
  "use": "check"
}

1 inline points in the source record.

p. 1650: ‘The highest k value was about 4350 cm^-1 for the band at approximately 1119A’, a band (the second member of a Rydberg series, Price and Simpson) on the 1121 A continuum, at 0.85 A band width. Approximate value and wavelength, a band peak at limited resolution: a check, not fitted.

inn_1953/continuum_f

{
  "id": "continuum_f",
  "material": "CO2",
  "table": "text",
  "quantity": "oscillator_strength",
  "abscissa": "label",
  "use": "check"
}

3 inline points in the source record.

pp. 1649-1650: oscillator strengths of the three continua, each ‘By symmetrical extrapolation of the curve for the continuum’ with the formula of Part I (not printed here; that of watanabe_1953): 0.0043 (maximum about 1475 A; Wilkinson and Johnston 0.004), 0.0053 (1332 A; overlap with the 1475 A continuum taken into account) and 0.12 (1121 A, ‘roughly 100 times more intense’). The index (1, 2, 3) only numbers the continua; the integration ranges are not stated. Checks.

Formulas

No formulas are recorded.

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.