peck_1966 ========= E\. R\. Peck and B\. N\. Khanna, J\. Opt\. Soc\. Am\. 56, 1059 \(1966\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` No DOI is recorded. **Source kind:** measurement **Recorded technique:** Corner\-reflector interferometer with a 24 cm gas cell in one arm and two light sources at once \(a visible reference line and a second line\), fringes counted as the gas is admitted and pumped out and interpolated to 0\.001 order; refractivity ratios independent of cell length and density\. Pressure by wide\-bore mercury manometer \(local g = 980\.302 cm/s^2\), temperature by thermocouple\. Matheson N2, 99\.996 %, through a dry\-ice cold trap\. **Materials in structured entries:** N2 **Dataset quantities:** refractivity, verdet\_constant\_ratio **Contents:** 5 datasets; 9 formulas. Curation notes -------------- Identity\: the library record is UNVERIFIED; the text is 'Dispersion of Nitrogen' by Edson R\. Peck and Baij Nath Khanna \(Northwestern University, received 3 December 1965\), file josa\-56\-8\-1059\.pdf, which matches the citation J\. Opt\. Soc\. Am\. 56, 1059\-1063 \(1966\) given for it by Griesmann \(1999\) and Peck & Huang \(1977\)\. No DOI is recorded \(the library has none\)\. Reduction\: to one atmosphere at T0 with the factor K of Eq\. \(2\), the real\-gas compressibility Z = 1 \- p \(317\.60 \- T\) 1e\-5 \(Eq\. 1, p in atm, from Hilsenrath's tables, 'developed under the old convention of 0 C = 273\.16 K'\) and a small Lorentz\-Lorenz correction\: density = real\. Wavelengths are vacuum \(Table I heading\)\. Table I gives relative values\: 'a nominal value of 10^8 \(n \- 1\) = 28 352\.40 at 15 C is taken for the mercury green line at vacuum wavelength 5462\.258 A; other values of refractivity are expressed in terms of this as a standard' \(p\. 1060\)\. The absolute measurement at 5462\.258 A is 28 352\.4 \+\- 1\.6 at 15 C and 1 atm \(statistical standard deviation of 22 sets of runs\), 'significant only to about four digits'; with 'a realistic estimate of total error', 10^6 \(n \- 1\) = 299\.14 \+\- 0\.10 at 0 C \(p\. 1060\)\. The relative values are about two orders of magnitude more precise\: the rms deviation of the 16 fitted points from Eq\. \(3\) is 0\.083e\-8, 'considered to be a better representation of precision than the individual standard deviations' \(p\. 1061\)\. Hence per point absolute = 0\.083 \(rms\) and systematic\_relative = 3\.3e\-4 \(0\.10 / 299\.14, the realistic total error, level not stated, taken as one sigma\)\. The 0 C absolute value is the same measurement converted, so it is not a separate dataset\. Three points \(5087\.242, 7034\.352, 13507\.884 A\) are printed in parentheses and were omitted from the fit as 'excessively far from the trend' \(the 7034 A neon line has an unresolved weak neighbour, p\. 1061\)\. Table II gives the dispersion of the Verdet constant as ratios to its value at 5780 A \(air wavelengths\), computed from Eq\. \(3\) and measured by Ingersoll & Liebenberg \(1954\); the computed column is a check of the formula, the measured one a reproduction\. Other results\: n\_inf \- 1 = 293\.77e\-6 at 0 C from Eq\. \(4\) \(p\. 1062; all formulas agree within 0\.01e\-6\); Verdet factor r = 0\.636 at 5462 A; the Rayleigh cross section 0\.5182e\-28 cm^2 at 30 degrees, 6945\.165 A in vacuo \(p\. 1063\)\. Svensson's air formula \(p\. 1061\) is skipped \(air is not a species\)\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- peck\_1966/experiment ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "experiment", "material": "N2", "file": "N2/peck_1966__experiment.csv", "table": "tbl_c2970086b7ad", "quantity": "refractivity", "scale": 1e-08, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_15C", "density": "real", "use": "primary", "uncertainty": { "absolute": 0.083, "level": "rms", "systematic_relative": 0.00033 } } The 16 fitted points, standardised to 28352\.40 at 5462\.258 A \(the absolute scale, \+\-3\.3e\-4, is the systematic uncertainty\)\. peck\_1966/experiment\_excluded ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "experiment_excluded", "material": "N2", "file": "N2/peck_1966__experiment_excluded.csv", "table": "tbl_c2970086b7ad", "quantity": "refractivity", "scale": 1e-08, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_15C", "density": "real", "use": "excluded" } The three values printed in parentheses, 0\.42, 1\.44 and 0\.65 \(x 1e\-8\) from Eq\. \(3\), omitted from the fit; 'the more correct value is given by the formula' \(p\. 1061\)\. peck\_1966/eq3 ~~~~~~~~~~~~~~ .. code-block:: text { "id": "eq3", "material": "N2", "file": "N2/peck_1966__eq3.csv", "table": "tbl_c2970086b7ad", "quantity": "refractivity", "scale": 1e-08, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_15C", "density": "real", "use": "check" } Table I 'Calculated refractivity'\: Eq\. \(3\) at the measured wavelengths\. peck\_1966/verdet\_ratio\_eq3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "verdet_ratio_eq3", "material": "N2", "file": "N2/peck_1966__verdet_ratio_eq3.csv", "table": "tbl_029c38d597ef", "quantity": "verdet_constant_ratio", "unit": "1", "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": "1atm_15C", "density": "real", "use": "check", "parameters": { "reference_wavelength_nm": 578.0 } } Table II 'Computed ratio'\: V\(lambda\)/V\(5780 A\) from Eq\. \(3\) through V/r proportional to sigma dn/dsigma \(p\. 1062\), with r constant\. The ratio is independent of the state to first order; the state is Eq\. \(3\)'s\. Row '5460\-61' placed at 5460\.5 A\. peck\_1966/verdet\_ratio\_ingersoll\_liebenberg ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "verdet_ratio_ingersoll_liebenberg", "material": "N2", "file": "N2/peck_1966__verdet_ratio_ingersoll_liebenberg.csv", "table": "tbl_029c38d597ef", "quantity": "verdet_constant_ratio", "unit": "1", "abscissa_unit": "angstrom", "wavelength_medium": "standard_air", "state": "1atm_15C", "density": "unknown", "use": "reproduced", "reproduced_from": [ "L. Ingersoll and D. Liebenberg, J. Opt. Soc. Am. 44, 566 (1954)" ], "parameters": { "reference_wavelength_nm": 578.0 } } Table II 'Ratio measured by Ingersoll and Liebenberg'\: V\(lambda\)/V\(5780 A\)\. The ratio to the dispersion formula \(the factor r of the Becquerel\-Serber relation\) is constant within 4\.4 % over 3635\-9875 A \(p\. 1063\); r itself is 0\.636 at 5462 A, so these ratios constrain dn/dsigma only through an assumed constant r\. The state is nominal \(the ratio does not depend on it to first order\)\. Formulas -------- peck\_1966/eq3 ~~~~~~~~~~~~~~ .. code-block:: text { "id": "eq3", "form": "dn_sigma2", "terms": { "scale": "1e-8", "A": "6497.378", "B": [ "3073864.9" ], "C": [ "144" ] }, "range_nm": [ 467.9, 2058.7 ], "material": "N2", "equation": "Eq. (3), p. 1061", "printed": "10^8 (n - 1) = 6497.378 + 3073864.9/(144 - sigma^2) (15 C)", "variable": "sigma: vacuum wavenumber in um^-1", "state": "1atm_15C", "density": "real", "range": "4679-20587 A (the data)", "coefficients": { "A": "6497.378", "B": "3073864.9", "C": "144" }, "check": "Reproduces Table I's calculated column to 0.01 at all 19 wavelengths; rms 0.083 over the 16 fitted points as stated (checked 2026-09-24)." } The paper's representation of its data\. 'A slightly better statistical fit is obtained by using a constant of 143\.647215' \(p\. 1061\), not given in full\. peck\_1966/eq4 ~~~~~~~~~~~~~~ .. code-block:: text { "id": "eq4", "form": "dn_sigma2", "terms": { "scale": "1e-8", "A": "6855.200", "B": [ "3243157.0" ], "C": [ "144" ] }, "range_nm": [ 467.9, 2058.7 ], "material": "N2", "equation": "Eq. (4), p. 1061", "printed": "10^8 (n - 1) = 6855.200 + 3243157.0/(144 - sigma^2) (0 C)", "variable": "sigma: vacuum wavenumber in um^-1", "state": "1atm_0C", "density": "real", "range": "4679-20587 A", "coefficients": { "A": "6855.200", "B": "3243157.0", "C": "144" }, "check": "Eq. (3) times 1.05507 in both coefficients, the real-gas density ratio 288.16/273.16 x Z(15 C)/Z(0 C) = 1.055071 from Eq. (1); n_inf - 1 = 293.77e-6 as stated (checked 2026-09-24)." } Eq\. \(3\) referred to 0 C\: not independent\. peck\_1966/eq5 ~~~~~~~~~~~~~~ .. code-block:: text { "id": "eq5", "material": "N2", "equation": "Eq. (5), p. 1061", "printed": "10^8 (n - 1) = 5109702.9/(183.69459 - sigma^2) + 212.949/(7.74396 + sigma^2) (15 C)", "variable": "sigma: vacuum wavenumber in um^-1", "state": "1atm_15C", "density": "real", "range": "4679-20587 A", "coefficients": { "B1": "5109702.9", "C1": "183.69459", "B2": "212.949", "C2": "-7.74396" }, "check": "rms 0.075 over the 16 fitted points as stated (checked 2026-09-24)." } The second term has '\+ sigma^2' in its denominator as printed \(a pole at imaginary wavenumber\); coefficient C2 is given with the sign that makes it a standard B/\(C \- sigma^2\) term\. peck\_1966/eq6 ~~~~~~~~~~~~~~ .. code-block:: text { "id": "eq6", "material": "N2", "equation": "Eq. (6), p. 1061", "printed": "10^8 (n - 1) = 5189259.2/(186.3764 - sigma^2) (15 C)", "variable": "sigma: vacuum wavenumber in um^-1", "state": "1atm_15C", "density": "real", "range": "4679-20587 A", "coefficients": { "B": "5189259.2", "C": "186.3764" }, "check": "rms 0.364 over the 16 points (paper: 0.363) (checked 2026-09-24)." } Single\-term fit, systematic trend; used for the effective oscillator \(732\.5 A, f = 4\.54\)\. peck\_1966/eq7 ~~~~~~~~~~~~~~ .. code-block:: text { "id": "eq7", "material": "N2", "equation": "Eq. (7), p. 1061", "printed": "10^8 (n - 1) = 5475062.8/(186.3764 - sigma^2) (0 C)", "variable": "sigma: vacuum wavenumber in um^-1", "state": "1atm_0C", "density": "real", "range": "4679-20587 A", "coefficients": { "B": "5475062.8", "C": "186.3764" }, "check": "Eq. (6) times 1.05508 (checked 2026-09-24)." } Eq\. \(6\) referred to 0 C\. peck\_1966/cuthbertson\_1910 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "cuthbertson_1910", "material": "N2", "equation": "p. 1062 (text)", "printed": "10^8 (n - 1) = 5.5939 x 10^6/(189.944 - sigma^2) (Cuthbertson and Cuthbertson)", "variable": "sigma: vacuum wavenumber in um^-1 (converted by Peck & Khanna assuming c = 3e10 cm/s in the original)", "state": "1atm_0C", "range": "not stated", "coefficients": { "B": "5.5939e6", "C": "189.944" }, "reproduced_from": [ "C. Cuthbertson and M. Cuthbertson, Proc. Roy. Soc. (London) 83A, 151 (1910)" ], "check": "Not checked." } Converted by Peck & Khanna from the original frequency form; state as for their comparison with Eq\. \(7\) \(0 C\), not stated explicitly\. peck\_1966/tausz\_1931 ~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "tausz_1931", "material": "N2", "equation": "p. 1062 (text)", "printed": "10^8 (n - 1) = 5.3607 x 10^6/(182.585 - sigma^2) (Tausz and Gorlacher)", "variable": "sigma: vacuum wavenumber in um^-1 (converted with the modern c)", "state": "1atm_0C", "range": "not stated", "coefficients": { "B": "5.3607e6", "C": "182.585" }, "reproduced_from": [ "J. Tausz and H. Gorlacher, Z. Tekhn. Phys. 12, 19, 123 (1931)" ], "check": "Not checked." } Converted by Peck & Khanna; state not stated explicitly \(compared with Eq\. 7\)\. peck\_1966/koch\_1913 ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "koch_1913", "material": "N2", "equation": "p. 1062 (text)", "printed": "(3/2) 10^8 (n^2 - 1)/(n^2 + 2) = 3953450/(152.294 - sigma^2) + 837340/(240.651 + sigma^2) (Koch)", "variable": "sigma: wavenumber in um^-1", "range": "not stated", "coefficients": { "B1": "3953450", "C1": "152.294", "B2": "837340", "C2": "-240.651" }, "reproduced_from": [ "J. Koch, Arkiv Math. Astron. Fysik 9 (No. 6), 1 (1913)" ], "check": "Not checked." } Fits the Lorentz\-Lorenz function, not n \- 1; '\+ sigma^2' in the second denominator as printed\. peck\_1966/wilkinson\_1960 ~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "wilkinson_1960", "material": "N2", "equation": "p. 1062 (text)", "printed": "10^8 (n - 1) = 6.3622 x 10^4/(45.989 - sigma^2) + 32453 x 10^6/(1065.11 - sigma^2) (Wilkinson)", "variable": "sigma: vacuum wavenumber in um^-1 (converted by Peck & Khanna)", "range": "Wilkinson's far-ultraviolet data", "coefficients": { "B1": "6.3622e4", "C1": "45.989", "B2": "32453e6", "C2": "1065.11" }, "reproduced_from": [ "P. G. Wilkinson, J. Opt. Soc. Am. 50, 1002 (1960)" ], "check": "Not checked. Griesmann & Burnett (1999) find it valid only between 180 and 200 nm." } Peck & Khanna also give a refit of Wilkinson's data, 10^8 \(n \- 1\) = 3\.76527e5/\(58\.0332 \- sigma^2\) \+ 2\.48645e6/\(83\.7400 \+ sigma^2\), which lowers the rms and mean absolute deviations to 87 % and 92 % \(p\. 1062\)\. 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.