bischel_1983 ============ W\. K\. Bischel and G\. Black, "Wavelength dependence of Raman scattering cross sections from 200\-600 nm", in Excimer Lasers\-1983, C\. K\. Rhodes, H\. Egger and H\. Pummer, Eds\., AIP Conf\. Proc\. 100, 181 \(American Institute of Physics, New York, 1983\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1063/1\.34046 `__ **Source kind:** measurement **Recorded technique:** Spontaneous vibrational Raman scattering, collected at 90 deg with an off\-axis elliptical mirror \(f/1\.4\) into a Spex 1402 double monochromator with an RCA 31034A photomultiplier and a boxcar integrator; gases at 1\-3 atm\. Pumps\: ArF \(193 nm\) and KrF \(248 nm\) excimer lasers, and a doubled or quadrupled Nd\:YAG laser Raman\-shifted in H2 for seven wavelengths between 217\.8 and 532\.0 nm\. Detection efficiency calibrated with a tungsten\-halogen lamp \(250\-700 nm\) and a D2 lamp \(200\-400 nm\), both traceable to NBS, agreeing to better than 10 % where they overlap; slit transmission from the signal against slit width\. Absolute scale\: the 532 nm signals ratioed to N2's, whose cross section \(Schroetter and Kloeckner, ref\. 2\) 'is known to better than \+\-5%' \(pp\. 181\-182\)\. **Materials in structured entries:** CH4, D2, H2, N2, O2 **Dataset quantities:** raman\_shift **Contents:** 5 datasets; 5 formulas. Curation notes -------------- AIP Conf\. Proc\. 100, pp\. 181\-187 \(Excimer Lasers\-1983\); PDF page 1 is the publisher's cover, and PDF page n is p\. 179 \+ n \(Table 1 is on p\. 186\)\. The library's citation\.bib lists spurious extra authors \('Test', 'Allman', \.\.\.\)\: the paper's authors are W\. K\. Bischel and G\. Black \(SRI International\), checked on the first page; the editors are C\. K\. Rhodes, H\. Egger and H\. Pummer \(the cover page\)\. The library's warnings \(figures without captions, the table's caption not attached\) are layout only\: the figure titles are printed under the figures, and Table 1's caption and fitted form are printed above it \(image checked\)\. WHAT IS MEASURED\: the absolute differential cross sections of the vibrational Q branches of H2 \(4156 cm\-1\), D2 \(2986\), CH4 nu1 \(2917\), N2 \(2331\) and O2 \(1555 cm\-1\) against the pump wavelength, 193\-532 nm \(p\. 181\)\. The measured values are in Figures 1 \(H2, with Huo's ab initio calculation dotted\), 2 \(H2 times lambda\_s^4, normalized to one at 532 nm\), 3 \(D2, N2, O2, CH4\) and 4 \(the single\-resonance fit, reduced cross section against the pump frequency squared, H2 and O2\) only\: not digitized\. Figure 5 is the calculated steady\-state gain of H2 Q\(1\) against wavelength\. TABLE 1 \(p\. 186, 'Single resonance fit to Raman scattering cross sections', dsigma/dOmega = A nu\_s^4/\(nu\_i^2 \- nu\_p^2\)^2; the library's unlabelled tbl\_377daa8e19f8; CSV = image\)\: per gas the Raman shift \(cm\-1\), A \(x 10^\-28 cm2 sr\-1\), nu\_i \(x 10^4 cm\-1\) and lambda\_i \(nm\) = 1/nu\_i\. The fits are the formulas below; the shifts are the datasets shift\_\* \(check\: the shifts that define nu\_s, not measured here\)\. 'We have fit our data to Equation 2 using a single effective intermediate state \.\.\. where the parameters A and nu\_i are determined from the x intercept and slope \.\.\. The solid lines plotted in Figures 1 and 3 were calculated with these parameters and they fit our data to within our experimental uncertainty' \(p\. 184\)\. ERRATUM\: Table 1 prints CH4's shift as 2986 cm\-1, D2's value on the row above; the text gives 'CH4 \(2917 cm\-1\)' \(p\. 181\), the nu1 band \(corrected below\)\. UNCERTAINTY\: 'our error bars of \+\-10%' \(p\. 183\); the lamps agree 'to better than 10%'; the N2 reference 'known to better than \+\-5%'\. For H2\: 'Except in the visible, our experimental values agree with the theoretical calculation \[Huo\] to better than our error bars of \+\-10% \.\.\. The discrepancy in the visible of approximately 10% is currently being studied' \(p\. 183\)\. 'The results for visible pump wavelengths agree with previous experiments to better than 5%' \(p\. 182\)\. No uncertainty is given for A and nu\_i\. RESONANCE\: 'at 193 nm, the \[H2\] cross section shows a resonant enhancement of approximately 2\.4' over the lambda\_s^4 scaling \(normalized at 532 nm, Fig\. 2\); 'At 193 nm, the O2 cross section shows a resonant enhancement of 22 over than expected from the lambda\_s^4 scaling law', near the Schumann\-Runge bands \(p\. 183\)\. The Eq\. \(1\)\-\(2\) reduction \(nu\_p ~ nu\_s\) is expected to be off by 'of order 10%' 'only for H2 using pump lasers in the visible' \(p\. 184\)\. OTHER TEXT VALUES \(notes only\)\: the H2 Rayleigh\-to\-Raman cross\-section ratio \(from Huo, ref\. 4, W\. Huo, private communication\) 'for lambda\_p = 600 nm, R = 155 and for lambda\_p = 200 nm R = 50' \(p\. 186\)\. The text cites 'recent Raman linewidth measurements made in our laboratory and elsewhere' as ref\. 6 \(p\. 184\), but the reference list ends at ref\. 5\: this paper holds no linewidth\. Refs\.\: 2 = Schroetter and Kloeckner in Raman Spectroscopy of Gases and Liquids, A\. Weber, ed\. \(Springer, 1979\); 4 = W\. Huo, private communication\. WAVELENGTHS\: nu\_p and nu\_s are 'frequencies' in cm\-1; the paper does not say whether the pump wavenumbers are vacuum \(the laser wavelengths are nominal\: 193, 248, 217\.8\-532\.0 nm\)\. The fits are checked below with nu\_p = 1/lambda\_p\. REPRODUCTIONS ELSEWHERE \(re\-pointed to this record 2026\-09\-27\)\: ottusch\_1988's dsigma\_H2, dsigma\_D2, dsigma\_CH4 \(532 nm\), everall\_1987's dsigma\_CH4, dsigma\_H2, dsigma\_O2, dsigma\_N2 \(248 nm\) and bischel\_1986b's formula cross\_section\_eq5 \(Ref\. 20 there\)\. Their values are formula evaluations or readings of the figures, not printed here\: see the formulas' checks\. hanna\_1986 cites 'Bischel and Black 1983 with Owyoung 1983' for its H2 51 MHz/atm linewidth\: this paper has no linewidth \(ref\. 6 above\), so that citation can only be to Owyoung's part\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- bischel\_1983/shift\_H2 ~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_H2", "material": "H2", "file": "H2/bischel_1983__shift_H2.csv", "table": "tbl_377daa8e19f8", "quantity": "raman_shift", "unit": "cm-1", "abscissa": "label", "use": "check", "parameters": { "transition": "v=0-1 Q branch" } } Table 1 \(p\. 186\), 'Raman Shift' of the H2 Q branch used in the fit \(4155; the text p\. 181 says 4156\)\: the shift defining nu\_s = nu\_p \- shift, not measured here\. bischel\_1983/shift\_D2 ~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_D2", "material": "D2", "file": "D2/bischel_1983__shift_D2.csv", "table": "tbl_377daa8e19f8", "quantity": "raman_shift", "unit": "cm-1", "abscissa": "label", "use": "check", "parameters": { "transition": "v=0-1 Q branch" } } Table 1 \(p\. 186\), 'Raman Shift' of the D2 Q branch used in the fit\: not measured here\. bischel\_1983/shift\_N2 ~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_N2", "material": "N2", "file": "N2/bischel_1983__shift_N2.csv", "table": "tbl_377daa8e19f8", "quantity": "raman_shift", "unit": "cm-1", "abscissa": "label", "use": "check", "parameters": { "transition": "v=0-1 Q branch" } } Table 1 \(p\. 186\), 'Raman Shift' of the N2 Q branch used in the fit\: not measured here\. bischel\_1983/shift\_O2 ~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_O2", "material": "O2", "file": "O2/bischel_1983__shift_O2.csv", "table": "tbl_377daa8e19f8", "quantity": "raman_shift", "unit": "cm-1", "abscissa": "label", "use": "check", "parameters": { "transition": "v=0-1 Q branch" } } Table 1 \(p\. 186\), 'Raman Shift' of the O2 Q branch used in the fit\: not measured here\. bischel\_1983/shift\_CH4 ~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_CH4", "material": "CH4", "file": "CH4/bischel_1983__shift_CH4.csv", "table": "tbl_377daa8e19f8", "quantity": "raman_shift", "unit": "cm-1", "abscissa": "label", "use": "check", "parameters": { "transition": "nu1 Q branch" } } Table 1 \(p\. 186\), 'Raman Shift' of CH4 \(nu1\) used in the fit, printed 2986 \(D2's value\)\: corrected to the text's 2917 by the erratum below\. Not measured here\. Formulas -------- bischel\_1983/single\_resonance\_H2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "single_resonance_H2", "material": "H2", "equation": "Table 1, p. 186 (Eq. 3, p. 184)", "printed": "dsigma/dOmega = A nu_s^4/(nu_i^2 - nu_p^2)^2; H2: Raman shift 4155 cm-1, A = 8.74 (x 10^-28) cm2 sr-1, nu_i = 8.48 (x 10^4 cm-1), lambda_i = 117.9 nm", "variable": "nu_p: the pump wavenumber, nu_s = nu_p - 4155: the Stokes wavenumber, nu_i: the effective intermediate state, all in cm-1 (nu_s^4/(nu_i^2 - nu_p^2)^2 is dimensionless); dsigma/dOmega: the absolute differential cross section of the whole vibrational Q branch in cm2 sr-1, per molecule, 90 deg scattering", "state": "room temperature (not stated); normal H2", "density": "unknown", "range": "pump 193-532 nm (the data; the title says 200-600 nm)", "coefficients": { "A": "8.74e-28", "nu_i": "8.48e4", "lambda_i": "117.9", "shift": "4155" }, "check": "Scratch (2026-09-27), nu_p = 1/lambda_p: lambda_i = 1/nu_i = 117.92 nm (printed 117.9). At 532 nm 8.59e-31 cm2/sr (ottusch_1988 quotes 0.81e-30 for Q(1) from this paper: 6 % lower; with bischel_1986b's R = 0.99, 8.51e-31); at 248.0/248.4 nm 4.83/4.79e-29 (everall_1987 quotes 4.8e-29). The 193 nm resonance factor over 532 nm, [(nu_i^2 - nu_532^2)/(nu_i^2 - nu_193^2)]^2 = 2.30 (text: 'approximately 2.4'). bischel_1986b's Eq. (5) uses these A and nu_i, and its Eq. (11) reproduces that paper's Table 1 to 0.25 %." } The single\-resonance form of Eq\. \(2\) \(p\. 184\), which assumes nu\_p ~ nu\_s; 'We expect small deviations \(of order 10%\) from the wavelength scaling given in Equation 2 only for H2 using pump lasers in the visible' \(p\. 184\)\. The fit is of the Q\-branch cross section; bischel\_1986b \(Eqs\. 6\-7\) describes it as the thermal average over the Q branch for linear pump polarization and no analyser and multiplies by R = 0\.99 for Q\(1\) with parallel polarizations\. Uncertainty of the data \+\-10 % \(p\. 183\); the absolute scale rests on Schroetter and Kloeckner's N2 cross section \(ref\. 2, \+\-5 %\)\. bischel\_1983/single\_resonance\_D2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "single_resonance_D2", "material": "D2", "equation": "Table 1, p. 186 (Eq. 3, p. 184)", "printed": "dsigma/dOmega = A nu_s^4/(nu_i^2 - nu_p^2)^2; D2: Raman shift 2986 cm-1, A = 3.90 (x 10^-28) cm2 sr-1, nu_i = 7.81 (x 10^4 cm-1), lambda_i = 128.0 nm", "variable": "nu_p: the pump wavenumber, nu_s = nu_p - 2986: the Stokes wavenumber, nu_i: the effective intermediate state, all in cm-1; dsigma/dOmega: the Q-branch differential cross section in cm2 sr-1, per molecule, 90 deg scattering", "state": "room temperature (not stated); normal D2", "density": "unknown", "range": "pump 193-532 nm (the data)", "coefficients": { "A": "3.90e-28", "nu_i": "7.81e4", "lambda_i": "128.0", "shift": "2986" }, "check": "Scratch (2026-09-27): lambda_i = 1/nu_i = 128.04 nm (printed 128.0). At 532 nm 7.38e-31 cm2/sr; ottusch_1988 quotes 0.79e-30 for D2 Q(2) from this paper (7 % higher than the Q-branch formula; not explained there)." } Figure 3 holds the D2 data \(not digitized\)\. Uncertainty of the data \+\-10 % \(p\. 183\)\. bischel\_1983/single\_resonance\_N2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "single_resonance_N2", "material": "N2", "equation": "Table 1, p. 186 (Eq. 3, p. 184)", "printed": "dsigma/dOmega = A nu_s^4/(nu_i^2 - nu_p^2)^2; N2: Raman shift 2331 cm-1, A = 3.02 (x 10^-28) cm2 sr-1, nu_i = 8.95 (x 10^4 cm-1), lambda_i = 111.8 nm", "variable": "nu_p: the pump wavenumber, nu_s = nu_p - 2331: the Stokes wavenumber, nu_i: the effective intermediate state, all in cm-1; dsigma/dOmega: the Q-branch differential cross section in cm2 sr-1, per molecule, 90 deg scattering", "state": "room temperature (not stated)", "density": "unknown", "range": "pump 193-532 nm (the data)", "coefficients": { "A": "3.02e-28", "nu_i": "8.95e4", "lambda_i": "111.8", "shift": "2331" }, "check": "Scratch (2026-09-27): 1/nu_i = 111.73 nm against the printed 111.8 (nu_i rounded: 111.8 nm is 8.945e4 cm-1). At 248.0/248.4 nm 1.54/1.53e-29 (everall_1987 quotes 1.52e-29); at 532 nm 3.79e-31 cm2/sr; at 488.0 nm 5.70e-31 cm2/sr, against the absolute values of danichkin_1981 (recommended 5.5 +- 0.2e-31) and hyatt_1973 (5.4 +- 0.3e-31): 4 % and 6 % higher." } The absolute scale of all five fits comes from the N2 cross section of Schroetter and Kloeckner \(ref\. 2\) at 532 nm \(p\. 182\), so this formula at 532 nm restates that reference rather than measuring it\. Figure 3 holds the N2 data \(not digitized\)\. bischel\_1983/single\_resonance\_O2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "single_resonance_O2", "material": "O2", "equation": "Table 1, p. 186 (Eq. 3, p. 184)", "printed": "dsigma/dOmega = A nu_s^4/(nu_i^2 - nu_p^2)^2; O2: Raman shift 1555 cm-1, A = 0.459 (x 10^-28) cm2 sr-1, nu_i = 5.69 (x 10^4 cm-1), lambda_i = 175.7 nm", "variable": "nu_p: the pump wavenumber, nu_s = nu_p - 1555: the Stokes wavenumber, nu_i: the effective intermediate state, all in cm-1; dsigma/dOmega: the Q-branch differential cross section in cm2 sr-1, per molecule, 90 deg scattering", "state": "room temperature (not stated)", "density": "unknown", "range": "pump 193-532 nm (the data); near-resonant below 250 nm (the Schumann-Runge bands)", "coefficients": { "A": "0.459e-28", "nu_i": "5.69e4", "lambda_i": "175.7", "shift": "1555" }, "check": "Scratch (2026-09-27): 1/nu_i = 175.75 nm (printed 175.7). At 248.0/248.4 nm 3.99/3.94e-29 (everall_1987 quotes 3.88e-29); at 532 nm 4.88e-31 (1.29 times N2's, as fenner_1973's Table II ratio 1.3). DOUBT: the resonance factor at 193 nm over 532 nm is 27.2 (26.4 at 193.3 nm) from the fit, against the text's 'resonant enhancement of 22' (p. 183): the fit is 20 % above the stated 193 nm enhancement, while the paper says the fits reproduce the data within the uncertainty." } Figures 3 and 4 hold the O2 data \(not digitized\)\. Uncertainty of the data \+\-10 % \(p\. 183\)\. bischel\_1983/single\_resonance\_CH4 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "single_resonance_CH4", "material": "CH4", "equation": "Table 1, p. 186 (Eq. 3, p. 184)", "printed": "dsigma/dOmega = A nu_s^4/(nu_i^2 - nu_p^2)^2; CH4 (nu1): Raman shift 2986 [misprint for 2917] cm-1, A = 10.4 (x 10^-28) cm2 sr-1, nu_i = 7.23 (x 10^4 cm-1), lambda_i = 138.3 nm", "variable": "nu_p: the pump wavenumber, nu_s = nu_p - 2917 (the text's shift; Table 1 prints 2986): the Stokes wavenumber, nu_i: the effective intermediate state, all in cm-1; dsigma/dOmega: the nu1 Q-branch differential cross section in cm2 sr-1, per molecule, 90 deg scattering", "state": "room temperature (not stated)", "density": "unknown", "range": "pump 193-532 nm (the data)", "coefficients": { "A": "10.4e-28", "nu_i": "7.23e4", "lambda_i": "138.3", "shift": "2917" }, "check": "Scratch (2026-09-27): 1/nu_i = 138.31 nm (printed 138.3). At 532 nm 2.78e-30 with the shift 2917 (2.74e-30 with the misprinted 2986); ottusch_1988 quotes 2.7e-30. At 248.0/248.4 nm 15.7/15.5e-29 (everall_1987 quotes 15.3e-29)." } The shift coefficient is the corrected 2917 cm\-1 \(the erratum of dataset shift\_CH4\: Table 1 prints 2986, D2's value; the text p\. 181 gives 2917\)\. Figure 3 holds the CH4 data \(not digitized\)\. Corrections ----------- .. code-block:: text [ { "dataset": "shift_CH4", "row": "nu1 Q branch", "column": "value", "printed": "2986", "corrected": "2917", "reason": "Table 1 prints CH4 (nu1)'s Raman shift as 2986 cm-1, the D2 shift of the row above; the CH4 nu1 Q branch is at 2917 cm-1.", "evidence": "The text lists the transitions studied as 'H2 (4156 cm-1), D2 (2986 cm-1), CH4 (2917 cm-1), N2 (2331 cm-1), and O2 (1555 cm-1)' (p. 181); the table image (tbl_377daa8e19f8) shows 2986 for both D2 and CH4. Every curated source puts CH4 nu1 at 2914-2917 cm-1 (fenner_1973 2914, danichkin_1981 2917, hanna_1986 2917). Checked 2026-09-27." } ] 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.