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 `__ · :doc:`Catalogue ` · :doc:`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 ~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 ~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "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 :doc:`review register ` for the checks and decisions.