liggett_1968 ============ G\. Liggett and J\. S\. Levinger, J\. Opt\. Soc\. Am\. 58, 109 \(1968\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1364/josa\.58\.000109 `__ **Source kind:** theory **Recorded technique:** Kramers\-Kronig calculation of delta\(E\) = Re\(n \- 1\) of neon and argon from photoabsorption cross sections \(Ederer and Tomboulian, Samson, Lukerskii, Allen\) and calculated discrete oscillator strengths \(Cooper, Sewell; for Ar 3p\-4s the average 0\.28 of Cooper, Knox, Geiger, Stacey and Vaughan\), scaled so that the TRK sum rule and the accepted static polarizability are reproduced; x\-ray region by Parratt and Hempstead's integrals over power\-law cross sections\. **Materials in structured entries:** Ar, Ne **Dataset quantities:** cauchy\_moment, polarizability, refractivity **Contents:** 18 datasets; 7 formulas. Curation notes -------------- Scaling \(pp\. 2\-3\)\: for neon the discrete strengths were multiplied by 0\.85 and the continuum by 0\.96; for argon all but the 3p\-4s strength by 1\.04\. The corrected neon oscillator strengths \(p\. 2\) are 2p\-3s 0\.138, 2p\-4s 0\.022, 2p\-5s 0\.008, 2p\-3d 0\.032, 2s\-3p 0\.067, 2s\-4p 0\.024, 2s\-5p 0\.011; argon \(p\. 3\)\: 3p\-4s 0\.28, 3p\-3d,5s 0\.239, 3p\-4d,6s 0\.127, 3p\-5d,7s 0\.071\. These are not extracted as datasets because the paper prints no transition wavelengths \(the package keys an oscillator strength to its wavelength\); they are recorded here\. Figures 1\-6 \(delta\(E\) from 0\.1 to 1000 Ry\) are not digitised\. Tables IV and V give delta\(E\) x 10^8 of neon \(302\-502 Ry\: \-1\.09 \.\.\. \-0\.40 'normal', \-1\.13 \.\.\. \-0\.40 this paper, \-1\.13 \.\.\. \-0\.41 Parratt\) and argon \(20\-4246 Ry\: e\.g\. at 20 Ry \-441\., \-107\., \-124\.; at 1415 Ry \-0\.090, \-0\.091, \-0\.091\) in the x\-ray region, where n \- 1 is negative; the 'normal' column is the free\-electron term \-CZN/E^2 \(Eq\. \(7\)\)\. They are not extracted\: the package's refractivity datasets must imply a positive polarizability\. Accuracy\: the results 'generally agree with existing theoretical calculations and experimental measurements to within 10 %' \(abstract\); the cross sections are 'known experimentally to an accuracy of about 5 %'\. The library marks Table II's caption as unmatched \(CAPTION\_UNMATCHED\)\: it is printed in the text above the table\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- liggett\_1968/mu4\_cuthbertson\_Ne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "mu4_cuthbertson_Ne", "material": "Ne", "file": "Ne/liggett_1968__mu4_cuthbertson_Ne.csv", "table": "tbl_699c13f7b3b4", "quantity": "cauchy_moment", "unit": "au", "scale": 16, "abscissa": "order", "abscissa_unit": "1", "use": "reproduced", "reproduced_from": [ "cuthbertson_1910", "cuthbertson_1932" ] } Table II, the negative fourth moment mu\_\-4 = sum f E^\-4 \+ R int sigma E^\-4 dE with energies in rydbergs \(Eq\. \(2\)\); since E\(Ry\) = 2 E\(hartree\), S\(\-4\) in atomic units is 16 mu\_\-4 \(scale 16; e\.g\. argon's 1\.76 x 16 = 28\.16, Langhoff and Karplus's S\(\-4\)\)\. 'Determined from the index of refraction, see Refs\. 3, 4 and Eq\. \(3\)' \(note a\)\: the Cauchy slope of C\. and M\. Cuthbertson's visible data, 'whose accuracy is about 10 %' \(p\. 1\)\. liggett\_1968/mu4\_ingersoll\_Ne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "mu4_ingersoll_Ne", "material": "Ne", "file": "Ne/liggett_1968__mu4_ingersoll_Ne.csv", "table": "tbl_699c13f7b3b4", "quantity": "cauchy_moment", "unit": "au", "scale": 16, "abscissa": "order", "abscissa_unit": "1", "use": "reproduced", "reproduced_from": [ "L. R. Ingersoll and D. H. Liebenberg, J. Opt. Soc. Am. 46, 538 (1956); J. Opt. Soc. Am. 44, 566 (1954)" ] } Table II, the negative fourth moment mu\_\-4 = sum f E^\-4 \+ R int sigma E^\-4 dE with energies in rydbergs \(Eq\. \(2\)\); since E\(Ry\) = 2 E\(hartree\), S\(\-4\) in atomic units is 16 mu\_\-4 \(scale 16; e\.g\. argon's 1\.76 x 16 = 28\.16, Langhoff and Karplus's S\(\-4\)\)\. 'Determined from the Verdet constant' measured by Ingersoll and Liebenberg \(note b\)\. liggett\_1968/mu4\_dalgarno\_Ne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "mu4_dalgarno_Ne", "material": "Ne", "file": "Ne/liggett_1968__mu4_dalgarno_Ne.csv", "table": "tbl_699c13f7b3b4", "quantity": "cauchy_moment", "unit": "au", "scale": 16, "abscissa": "order", "abscissa_unit": "1", "use": "reproduced", "reproduced_from": [ "A. Dalgarno (as quoted by F. Marmo in a private communication); A. Dalgarno and A. E. Kingston, Proc. Roy. Soc. (London) A259, 424 (1960)" ] } Table II, the negative fourth moment mu\_\-4 = sum f E^\-4 \+ R int sigma E^\-4 dE with energies in rydbergs \(Eq\. \(2\)\); since E\(Ry\) = 2 E\(hartree\), S\(\-4\) in atomic units is 16 mu\_\-4 \(scale 16; e\.g\. argon's 1\.76 x 16 = 28\.16, Langhoff and Karplus's S\(\-4\)\)\. 'Calculation by extrapolation from other moments, see Ref\. 21' \(note c; Ref\. 21 is Dalgarno as quoted by Marmo; the text, p\. 3, attributes the value to 'Dalgarno's and Kingston's calculated value', Ref\. 20\)\. liggett\_1968/mu4\_theory\_Ne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "mu4_theory_Ne", "material": "Ne", "file": "Ne/liggett_1968__mu4_theory_Ne.csv", "table": "tbl_699c13f7b3b4", "quantity": "cauchy_moment", "unit": "au", "scale": 16, "abscissa": "order", "abscissa_unit": "1", "use": "check" } Table II, the negative fourth moment mu\_\-4 = sum f E^\-4 \+ R int sigma E^\-4 dE with energies in rydbergs \(Eq\. \(2\)\); since E\(Ry\) = 2 E\(hartree\), S\(\-4\) in atomic units is 16 mu\_\-4 \(scale 16; e\.g\. argon's 1\.76 x 16 = 28\.16, Langhoff and Karplus's S\(\-4\)\)\. 'This paper'\: from the corrected cross sections and oscillator strengths, a check of them \(p\. 3\)\. liggett\_1968/mu4\_cuthbertson\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "mu4_cuthbertson_Ar", "material": "Ar", "file": "Ar/liggett_1968__mu4_cuthbertson_Ar.csv", "table": "tbl_699c13f7b3b4", "quantity": "cauchy_moment", "unit": "au", "scale": 16, "abscissa": "order", "abscissa_unit": "1", "use": "reproduced", "reproduced_from": [ "cuthbertson_1910", "cuthbertson_1932" ] } Table II, the negative fourth moment mu\_\-4 = sum f E^\-4 \+ R int sigma E^\-4 dE with energies in rydbergs \(Eq\. \(2\)\); since E\(Ry\) = 2 E\(hartree\), S\(\-4\) in atomic units is 16 mu\_\-4 \(scale 16; e\.g\. argon's 1\.76 x 16 = 28\.16, Langhoff and Karplus's S\(\-4\)\)\. 'Determined from the index of refraction, see Refs\. 3, 4 and Eq\. \(3\)' \(note a\)\: the Cauchy slope of C\. and M\. Cuthbertson's visible data, 'whose accuracy is about 10 %' \(p\. 1\)\. liggett\_1968/mu4\_ingersoll\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "mu4_ingersoll_Ar", "material": "Ar", "file": "Ar/liggett_1968__mu4_ingersoll_Ar.csv", "table": "tbl_699c13f7b3b4", "quantity": "cauchy_moment", "unit": "au", "scale": 16, "abscissa": "order", "abscissa_unit": "1", "use": "reproduced", "reproduced_from": [ "L. R. Ingersoll and D. H. Liebenberg, J. Opt. Soc. Am. 46, 538 (1956); J. Opt. Soc. Am. 44, 566 (1954)" ] } Table II, the negative fourth moment mu\_\-4 = sum f E^\-4 \+ R int sigma E^\-4 dE with energies in rydbergs \(Eq\. \(2\)\); since E\(Ry\) = 2 E\(hartree\), S\(\-4\) in atomic units is 16 mu\_\-4 \(scale 16; e\.g\. argon's 1\.76 x 16 = 28\.16, Langhoff and Karplus's S\(\-4\)\)\. 'Determined from the Verdet constant' measured by Ingersoll and Liebenberg \(note b\)\. liggett\_1968/mu4\_dalgarno\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "mu4_dalgarno_Ar", "material": "Ar", "file": "Ar/liggett_1968__mu4_dalgarno_Ar.csv", "table": "tbl_699c13f7b3b4", "quantity": "cauchy_moment", "unit": "au", "scale": 16, "abscissa": "order", "abscissa_unit": "1", "use": "reproduced", "reproduced_from": [ "A. Dalgarno (as quoted by F. Marmo in a private communication); A. Dalgarno and A. E. Kingston, Proc. Roy. Soc. (London) A259, 424 (1960)" ] } Table II, the negative fourth moment mu\_\-4 = sum f E^\-4 \+ R int sigma E^\-4 dE with energies in rydbergs \(Eq\. \(2\)\); since E\(Ry\) = 2 E\(hartree\), S\(\-4\) in atomic units is 16 mu\_\-4 \(scale 16; e\.g\. argon's 1\.76 x 16 = 28\.16, Langhoff and Karplus's S\(\-4\)\)\. 'Calculation by extrapolation from other moments, see Ref\. 21' \(note c; Ref\. 21 is Dalgarno as quoted by Marmo; the text, p\. 3, attributes the value to 'Dalgarno's and Kingston's calculated value', Ref\. 20\)\. liggett\_1968/mu4\_theory\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "mu4_theory_Ar", "material": "Ar", "file": "Ar/liggett_1968__mu4_theory_Ar.csv", "table": "tbl_699c13f7b3b4", "quantity": "cauchy_moment", "unit": "au", "scale": 16, "abscissa": "order", "abscissa_unit": "1", "use": "check" } Table II, the negative fourth moment mu\_\-4 = sum f E^\-4 \+ R int sigma E^\-4 dE with energies in rydbergs \(Eq\. \(2\)\); since E\(Ry\) = 2 E\(hartree\), S\(\-4\) in atomic units is 16 mu\_\-4 \(scale 16; e\.g\. argon's 1\.76 x 16 = 28\.16, Langhoff and Karplus's S\(\-4\)\)\. 'This paper'\: from the corrected cross sections and oscillator strengths, a check of them \(p\. 3\)\. liggett\_1968/lyman\_marmo\_Ne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "lyman_marmo_Ne", "material": "Ne", "file": "Ne/liggett_1968__lyman_marmo_Ne.csv", "table": "tbl_7b2a63bc8b39", "quantity": "refractivity", "scale": 0.0001, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "reproduced", "reproduced_from": [ "F. Marmo, Bull. Am. Phys. Soc. 9, 626 (1964); 10, 691 (1965), and private communication" ] } Table III, delta\(E\) = n \- 1 \(x 10^4\) at the hydrogen Lyman alpha line \(the paper names the line, 0\.75 Ry; wavelength 1215\.67 A as printed by Mahon et al\. 1979\)\. The paper does not state the density N of its Eq\. \(1\); taken as NTP, as the measurements compared are\. 'Measurement from Rayleigh scattering, Ref\. 7' \(Marmo, unpublished\)\: the original is not available, so this reproduction may be fitted; no uncertainty given\. Rayleigh scattering gives \|n \- 1\| \(p\. 1\)\. liggett\_1968/lyman\_marmo\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "lyman_marmo_Ar", "material": "Ar", "file": "Ar/liggett_1968__lyman_marmo_Ar.csv", "table": "tbl_7b2a63bc8b39", "quantity": "refractivity", "scale": 0.0001, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "reproduced", "reproduced_from": [ "F. Marmo, Bull. Am. Phys. Soc. 9, 626 (1964); 10, 691 (1965), and private communication" ] } Table III, delta\(E\) = n \- 1 \(x 10^4\) at the hydrogen Lyman alpha line \(the paper names the line, 0\.75 Ry; wavelength 1215\.67 A as printed by Mahon et al\. 1979\)\. The paper does not state the density N of its Eq\. \(1\); taken as NTP, as the measurements compared are\. Marmo's Rayleigh\-scattering value \(unpublished; see lyman\_marmo\_Ne\)\. Marmo's Ne/Ar ratio, 0\.152, is reproduced by Leonard 1974 \(Table III\(b\), Ref\. 40\)\. liggett\_1968/lyman\_dalgarno\_Ne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "lyman_dalgarno_Ne", "material": "Ne", "file": "Ne/liggett_1968__lyman_dalgarno_Ne.csv", "table": "tbl_7b2a63bc8b39", "quantity": "refractivity", "scale": 0.0001, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "reproduced", "reproduced_from": [ "A. Dalgarno (as quoted by F. Marmo in a private communication)" ] } Table III, delta\(E\) = n \- 1 \(x 10^4\) at the hydrogen Lyman alpha line \(the paper names the line, 0\.75 Ry; wavelength 1215\.67 A as printed by Mahon et al\. 1979\)\. The paper does not state the density N of its Eq\. \(1\); taken as NTP, as the measurements compared are\. 'Calculation, Ref\. 21' \(Dalgarno, private communication via Marmo\)\. liggett\_1968/lyman\_theory\_Ne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "lyman_theory_Ne", "material": "Ne", "file": "Ne/liggett_1968__lyman_theory_Ne.csv", "table": "tbl_7b2a63bc8b39", "quantity": "refractivity", "scale": 0.0001, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "check" } Table III, delta\(E\) = n \- 1 \(x 10^4\) at the hydrogen Lyman alpha line \(the paper names the line, 0\.75 Ry; wavelength 1215\.67 A as printed by Mahon et al\. 1979\)\. The paper does not state the density N of its Eq\. \(1\); taken as NTP, as the measurements compared are\. 'This paper'\: the Kramers\-Kronig calculation with cross sections and oscillator strengths scaled to the accepted polarizability and the TRK sum rule; results 'generally agree \.\.\. to within 10 %' \(abstract\)\. liggett\_1968/lyman\_dalgarno\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "lyman_dalgarno_Ar", "material": "Ar", "file": "Ar/liggett_1968__lyman_dalgarno_Ar.csv", "table": "tbl_7b2a63bc8b39", "quantity": "refractivity", "scale": 0.0001, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "reproduced", "reproduced_from": [ "A. Dalgarno (as quoted by F. Marmo in a private communication)" ] } Table III, delta\(E\) = n \- 1 \(x 10^4\) at the hydrogen Lyman alpha line \(the paper names the line, 0\.75 Ry; wavelength 1215\.67 A as printed by Mahon et al\. 1979\)\. The paper does not state the density N of its Eq\. \(1\); taken as NTP, as the measurements compared are\. 'Calculation, Ref\. 21' \(Dalgarno, private communication via Marmo\)\. liggett\_1968/lyman\_theory\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "lyman_theory_Ar", "material": "Ar", "file": "Ar/liggett_1968__lyman_theory_Ar.csv", "table": "tbl_7b2a63bc8b39", "quantity": "refractivity", "scale": 0.0001, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "check" } Table III, delta\(E\) = n \- 1 \(x 10^4\) at the hydrogen Lyman alpha line \(the paper names the line, 0\.75 Ry; wavelength 1215\.67 A as printed by Mahon et al\. 1979\)\. The paper does not state the density N of its Eq\. \(1\); taken as NTP, as the measurements compared are\. 'This paper'\: the Kramers\-Kronig calculation with cross sections and oscillator strengths scaled to the accepted polarizability and the TRK sum rule; results 'generally agree \.\.\. to within 10 %' \(abstract\)\. liggett\_1968/lyman\_heddle\_1963\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "lyman_heddle_1963_Ar", "material": "Ar", "file": "Ar/liggett_1968__lyman_heddle_1963_Ar.csv", "table": "tbl_7b2a63bc8b39", "quantity": "refractivity", "scale": 0.0001, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "reproduced", "reproduced_from": [ "heddle_1963" ] } Table III, delta\(E\) = n \- 1 \(x 10^4\) at the hydrogen Lyman alpha line \(the paper names the line, 0\.75 Ry; wavelength 1215\.67 A as printed by Mahon et al\. 1979\)\. The paper does not state the density N of its Eq\. \(1\); taken as NTP, as the measurements compared are\. 'Measurement using Cherenkov radiation, Ref\. 8'\: Heddle et al\.'s value at 1210 \+\- 30 A, listed here under Lyman alpha; identical to heddle\_1963/experiment\_Ar at 1210 A\. liggett\_1968/lyman\_kingston\_1964\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "lyman_kingston_1964_Ar", "material": "Ar", "file": "Ar/liggett_1968__lyman_kingston_1964_Ar.csv", "table": "tbl_7b2a63bc8b39", "quantity": "refractivity", "scale": 0.0001, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "reproduced", "reproduced_from": [ "kingston_1964" ] } Table III, delta\(E\) = n \- 1 \(x 10^4\) at the hydrogen Lyman alpha line \(the paper names the line, 0\.75 Ry; wavelength 1215\.67 A as printed by Mahon et al\. 1979\)\. The paper does not state the density N of its Eq\. \(1\); taken as NTP, as the measurements compared are\. 'Calculation, Ref\. 2' \(Kingston 1964\)\. Kingston's own value at 1216 A is 5\.30 \(his Table III; 5\.542 at 1200 A in Table I\); 5\.20 is not in his paper as printed \(unexplained\)\. liggett\_1968/accepted\_polarizability\_Ne ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "accepted_polarizability_Ne", "material": "Ne", "table": "text", "quantity": "polarizability", "unit": "au", "abscissa_unit": "angstrom", "use": "reproduced", "reproduced_from": [ "cuthbertson_1932" ] } 1 inline points in the source record. p\. 2\: 'the accepted value, alpha = 2\.70 atomic units' \(Ref\. 4, C\. and M\. Cuthbertson 1932\), to which the neon oscillator strengths and cross sections were scaled\. liggett\_1968/accepted\_polarizability\_Ar ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "accepted_polarizability_Ar", "material": "Ar", "table": "text", "quantity": "polarizability", "unit": "au", "abscissa_unit": "angstrom", "use": "reproduced", "reproduced_from": [ "cuthbertson_1932" ] } 1 inline points in the source record. p\. 3\: 'the accepted values \.\.\. alpha = 11\.1 atomic units' \(Ref\. 4\), to which the argon cross sections were scaled\. Formulas -------- liggett\_1968/cross\_section\_Ne\_13p0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "cross_section_Ne_13p0", "material": "Ne", "equation": "Table I, p. 2", "printed": "1.12 \\times 10^{3}E^{-2.59} (MB)", "variable": "E: photon energy in rydbergs; sigma in megabarns", "state": "per atom", "density": "unknown", "range": "13.0-63.7 Ry", "coefficients": { "A": "1.12e3", "p": "2.59" }, "check": "Not checkable against printed values (the cross sections enter only the Kramers-Kronig integral)." } Photoionisation cross\-section power law sigma = A E^\-p used above 11 Ry for neon \(compiled by Piech and Levinger 1964, Ref\. 10; Table I note b\); Table I note a\: 'Allen, Ref\. 16 and Lukerskii, Ref\. 15'\. Not a refractivity formula; recorded because the x\-ray refractivities of Tables IV\-V follow from it through Parratt and Hempstead's integrals\. liggett\_1968/cross\_section\_Ne\_63p7 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "cross_section_Ne_63p7", "material": "Ne", "equation": "Table I, p. 2", "printed": "3.24 \\times 10^{4}E^{-2.72} (MB)", "variable": "E: photon energy in rydbergs; sigma in megabarns", "state": "per atom", "density": "unknown", "range": "63.7-227.8 Ry", "coefficients": { "A": "3.24e4", "p": "2.72" }, "check": "Not checkable against printed values (the cross sections enter only the Kramers-Kronig integral)." } Photoionisation cross\-section power law sigma = A E^\-p used above 11 Ry for neon \(compiled by Piech and Levinger 1964, Ref\. 10; Table I note b\); Table I note a\: 'Allen, Ref\. 16 and Lukerskii, Ref\. 15'\. Not a refractivity formula; recorded because the x\-ray refractivities of Tables IV\-V follow from it through Parratt and Hempstead's integrals\. liggett\_1968/cross\_section\_Ne\_227p8 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "cross_section_Ne_227p8", "material": "Ne", "equation": "Table I, p. 2", "printed": "1.10 \\times 10^{5}E^{-2.89} (MB)", "variable": "E: photon energy in rydbergs; sigma in megabarns", "state": "per atom", "density": "unknown", "range": "227.8-911.3 Ry", "coefficients": { "A": "1.10e5", "p": "2.89" }, "check": "Not checkable against printed values (the cross sections enter only the Kramers-Kronig integral)." } Photoionisation cross\-section power law sigma = A E^\-p used above 11 Ry for neon \(compiled by Piech and Levinger 1964, Ref\. 10; Table I note b\); Table I note a\: 'Allen, Ref\. 16 and Lukerskii, Ref\. 15'\. Not a refractivity formula; recorded because the x\-ray refractivities of Tables IV\-V follow from it through Parratt and Hempstead's integrals\. liggett\_1968/cross\_section\_Ar\_18p2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "cross_section_Ar_18p2", "material": "Ar", "equation": "Table I, p. 2", "printed": "1.13 \\times 10^{5}E^{-2.75} (MB)", "variable": "E: photon energy in rydbergs; sigma in megabarns", "state": "per atom", "density": "unknown", "range": "18.2-21.6 Ry", "coefficients": { "A": "1.13e5", "p": "2.75" }, "check": "Not checkable against printed values (the cross sections enter only the Kramers-Kronig integral)." } Photoionisation cross\-section power law sigma = A E^\-p used beyond the K edge region for argon, fitted by the authors to Allen's compilation \(Ref\. 16\) and Lukerskii \(Ref\. 15\); Table I note a\: 'Allen, Ref\. 16 and Lukerskii, Ref\. 15'\. Not a refractivity formula; recorded because the x\-ray refractivities of Tables IV\-V follow from it through Parratt and Hempstead's integrals\. liggett\_1968/cross\_section\_Ar\_21p6 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "cross_section_Ar_21p6", "material": "Ar", "equation": "Table I, p. 2", "printed": "5.94 \\times 10^{4}E^{-2.40} (MB)", "variable": "E: photon energy in rydbergs; sigma in megabarns", "state": "per atom", "density": "unknown", "range": "21.6-60.7 Ry", "coefficients": { "A": "5.94e4", "p": "2.40" }, "check": "Not checkable against printed values (the cross sections enter only the Kramers-Kronig integral)." } Photoionisation cross\-section power law sigma = A E^\-p used beyond the K edge region for argon, fitted by the authors to Allen's compilation \(Ref\. 16\) and Lukerskii \(Ref\. 15\); Table I note a\: 'Allen, Ref\. 16 and Lukerskii, Ref\. 15'\. Not a refractivity formula; recorded because the x\-ray refractivities of Tables IV\-V follow from it through Parratt and Hempstead's integrals\. liggett\_1968/cross\_section\_Ar\_60p7 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "cross_section_Ar_60p7", "material": "Ar", "equation": "Table I, p. 2", "printed": "1.48 \\times 10^{5}E^{-2.61} (MB)", "variable": "E: photon energy in rydbergs; sigma in megabarns", "state": "per atom", "density": "unknown", "range": "60.7-235.9 Ry", "coefficients": { "A": "1.48e5", "p": "2.61" }, "check": "Not checkable against printed values (the cross sections enter only the Kramers-Kronig integral)." } Photoionisation cross\-section power law sigma = A E^\-p used beyond the K edge region for argon, fitted by the authors to Allen's compilation \(Ref\. 16\) and Lukerskii \(Ref\. 15\); Table I note a\: 'Allen, Ref\. 16 and Lukerskii, Ref\. 15'\. Not a refractivity formula; recorded because the x\-ray refractivities of Tables IV\-V follow from it through Parratt and Hempstead's integrals\. liggett\_1968/cross\_section\_Ar\_235p9 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "cross_section_Ar_235p9", "material": "Ar", "equation": "Table I, p. 2", "printed": "3.30 \\times 10^{6}E^{-2.75} (MB)", "variable": "E: photon energy in rydbergs; sigma in megabarns", "state": "per atom", "density": "unknown", "range": "235.9-4564.5 Ry", "coefficients": { "A": "3.30e6", "p": "2.75" }, "check": "Not checkable against printed values (the cross sections enter only the Kramers-Kronig integral)." } Photoionisation cross\-section power law sigma = A E^\-p used beyond the K edge region for argon, fitted by the authors to Allen's compilation \(Ref\. 16\) and Lukerskii \(Ref\. 15\); Table I note a\: 'Allen, Ref\. 16 and Lukerskii, Ref\. 15'\. Not a refractivity formula; recorded because the x\-ray refractivities of Tables IV\-V follow from it through Parratt and Hempstead's integrals\. 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.