mcguire_1981#
E. J. McGuire, “Two- and three-photon ionization in the noble gases”, Phys. Rev. A 24, 835-848 (1981)
Source record · Catalogue · Review register
Source kind: theory
Recorded technique: Lowest-order perturbation theory in a central potential: an approximation to the Hermann-Skillman potential (r V(r) as a series of straight lines) for which the Schrödinger equation is solvable in Whittaker functions and the characteristic (radial) Green’s function is exact, replacing the sum over intermediate states (p. 835, Eqs. 4 and 8; McGuire, Phys. Rev. A 23, 186 (1981), Ref. 17). jl coupling, ‘appropriate for the noble gases’ (p. 835): the intermediate and final states are labelled by the (np)5 core’s J_f (3/2 or 1/2), with K = J_f + l and J = K + 1/2; the continuum electron’s energy is 2 omega - E0 or 2 omega - E0 - Delta_so, Delta_so the ion’s ground-state spin-orbit splitting (p. 836). Dipole-length matrix elements (<n0 p| r |n1 l1>, Eqs. 2a-2d). Two-photon: eight Green’s functions (J_f = 3/2, 1/2; l1 = s, d; K1), final continua l_f = 1 and 3; circular and linear polarisation from Eqs. (3a) and (3b). Ne, Ar, Kr and Xe; two-photon from threshold to about 600 (Ne), 825 (Ar), 945 (Kr) and 1100 angstrom (Xe); three-photon also (Figs. 5-8, not taken). No numerical uncertainty of the calculation is stated.
Materials in structured entries: Ar, Kr, Ne, Xe
Dataset quantities: multiphoton_ionization_cross_section, multiphoton_ionization_polarization_ratio
Contents: 8 datasets; 0 formulas.
Curation notes#
Journal pp. 835-848 = PDF pages 1-14 (journal page = PDF page + 834). A scan: every page is one 1-bit image (4816 x 6367 pixels, about 600 dpi), no text layer. Identity checked on the first page (Physical Review A, volume 24, number 2, August 1981; E. J. McGuire, Sandia National Laboratories; received 22 August 1980, revised 24 March 1981) on 2026-10-08.
THE CROSS SECTION (p. 836, Eq. 1): ‘For two-photon ionization the cross sections sigma_2^C and sigma_2^L, for circularly and linearly polarized light, in units of cm^4 sec are given by sigma_2^i = 4 pi (Delta E / F0)^2 (M_2^i)^2’, Delta E the photon energy in Ry, the continuum orbital normalised per Ry, F0 = 3.22 x 10^34 / cm^2 sec (the factor’s dependence on the energy units is in Ref. 17). In cm^4 s the generalised cross section of the rate per atom W = sigma_2 Phi^2, Phi the photon flux in cm^-2 s^-1 (as uiterwaal_1998 and mckenna_2004): McCown et al. (mccown_1982) quote McGuire’s Xe value at 193 nm as a coefficient alpha = sigma_2 / (hbar omega), 8 x 10^-32 cm^4 W^-1, and alpha hbar omega at 1930 angstrom (8.23e-50 cm4 s) is 1.5 % below the curve read here (8.36e-50): their conversion, which is this definition, reproduces the figure. sigma_2^L is not drawn: it is sigma_2^C / R, from the two datasets of a figure at the same wavelength (not stored). From Eqs. (3a)-(3b), R = 3/2 where the l_f = 3 continuum dominates (its largest value), R = 1 at the (np)5 n’s resonances, and R can fall to 1/4 (nd, nd’) or 1/34 (nd’’) where the l_f = 1 continuum dominates (p. 837). Three-photon: sigma_3 = 8 pi (Delta E / F0)^3 (M_3)^2, cm^6 s^2 (Eq. 5).
THE ENERGY AXIS. The figures’ abscissa is the photon wavelength in angstrom (one photon; the two-photon energy is twice the photon energy). Its medium is not stated: taken as vacuum (the default; below 2000 angstrom the difference from an air wavelength is below 0.7 angstrom, under the reading’s resolution in every segment but the 1-angstrom ones of Figs. 1 and 3). The resonance positions are adjusted, not calculated: ‘The Green’s function contains one free parameter (the ionization energy). It can be adjusted to produce a resonance at its experimental value. But this choice fixes the energy of all other resonances with the same quantum numbers’ (p. 835). For the matrix element to diverge at the experimental level E1(J_f, n1 l1 K1 1) (Moore’s tables, Ref. 18), E0 in each Green’s function is changed to E0 - E(n1 l1) + E1, E(n1 l1) the model one-electron eigenvalue; ‘For a particular range in omega it is assumed that only the nearest resonance with a particular l value need have its resonance energy specified exactly. By changing E0, one shifts all the resonances with a given J_f, l1 and K1’ (p. 836): the lowest (or nearest) member of each series sits at its experimental position, the higher members move with it. ‘the free parameter was adjusted in different spectral ranges ... This led to match-up problems at the boundary of the spectral ranges, i.e., differences of as much as twenty-five percent, and the differences were smoothed over’ (p. 835): the drawn curves carry that smoothing. ‘Generally the adjustments are less than ten percent of the separation of corresponding levels, though there are exceptions’ (p. 836). The resonances are jl (J-resolved) levels: ns (K = 3/2) and ns’ (J_f = 1/2) separately, nd, nd’ and nd’’ (p. 837). In Ar the author’s LS-coupling variant (resonances relocated to the LS positions, the open circles of Fig. 2) does not remove a factor-of-2 difference from Pindzola and Kelly; he attributes it to the shift of the higher ns, ns’ resonances to longer wavelengths that the adjustment causes (p. 844). Xe (p. 844): ‘there is a step in both sigma_2^C and R at 1843 A. At longer wavelengths ionization to the (5p)5 2P1/2 channel is energetically forbidden. For lambda > 1843 A, Beutler structure should be present with large and interesting resonance effects. They have been neglected in these calculations.’ The autoionising resonances between the 2P3/2 and 2P1/2 limits are therefore absent in every gas (the curves between the two thresholds are smooth continua).
EXTRACTED (tools/extract/mcguire_1981.py), by data rule 8 (TC-699): no cross section or ratio is printed as a number; Figs. 1-4 (pp. 842-843) are read from the page images at native resolution. Each figure draws sigma_2^C (solid line, logarithmic left axis, cm^4 s) and R (crosses joined by a line, logarithmic right axis) on one frame. ‘The wavelength scale in the figures is not linear; it is compressed when the cross sections vary slowly and expanded near resonances’ (p. 837): the axis is calibrated segment by segment from its own ticks (labelled ticks, and in the compressed stretches the unlabelled minor ticks that divide the interval between two labels evenly), each segment a straight line checked through its ticks. Worst tick residuals, pixels, per segment: Fig. 1 (592-604 by 1, 604-610 by 1 (minor), 610-640 by 5, 640-700 by 10 (minor), 700-730 by 10 (minor), 730-750 by 5, 750-1150 by 50 angstrom) 1.9, 2.4, 1.6, 1.7, 2.3, 1.9, 2.2; Fig. 2 (825-910 by 5, 910-950 by 10, 1000-1040 by 10, 1040-1070 by 10, 1070-1100 by 10, 1100-1400 by 50) 1.7, 1.3, 1.8, 1.4, 0.7, 1.9; Fig. 3 (945-950 by 1, 950-1050 by 10, 1050-1100 by 10, 1160-1170 by 5, 1170-1200 by 10, 1200-1230 by 10, 1230-1240 by 5, 1250-1600 by 50) 1.6, 1.7, 1.7, 2.2, 0.9, 0.5, 0.3, 2.7; Fig. 4 (1100-1340 by 20 and 10, 1340-1400 by 20, 1460-1480 by 10, 1500-2000 by 100) 2.9, 0.4, 1.2, 1.3. LEFT OUT, stretches spanned by a single division between two labels, with no tick between them to check a scale: Fig. 2 950-1000; Fig. 3 1100-1150, 1150-1160 and 1240-1250; Fig. 4 1400-1460 and 1480-1500 angstrom. The frames’ left and right lines are ticks where a label stands at the corner (Fig. 1 592 and 1150, Fig. 2 825 and 1400, Fig. 3 945, Fig. 4 1100). The log axes are calibrated decade by decade from their ticks (every decade and 2-9 times it; worst residual 3.5 pixels left, 4.0 right, Fig. 3’s R decade 1-10); the decades of one figure differ in length by up to 3 % (Fig. 2: 288 to 296 pixels). The scan’s frames tilt by up to 0.005 (the frame lines fitted within 2 pixels); a pixel is referred to the bottom axis along the frame’s sides and to the left axis at the same height in the frame. The top axis’s ticks lie up to 12 pixels (median 2-5.5) to the right of where the frame’s sides carry the bottom ticks: a drawing offset, not the scan’s (the frame’s sides are straight); it is part of the wavelength uncertainty of the R curve, which runs near the top (at most 0.1 angstrom in the 1-angstrom segments, 6 angstrom in the 50-angstrom ones). The curves are traced column by column from seed pixels; sigma_2^C is sampled at regular wavelengths (every 0.2 to 20 angstrom by segment) where the line’s run is at most 18 pixels tall there and 3 columns either side (no steep flank, no resonance tip: the peaks and steep wings of the resonances are not read); R where the cluster of the crosses and line is at most 45 pixels tall and does not touch the R = 1.5 line (where the curve runs into that line, R is within a line width of it, about R > 1.4, and is not read), so R’s dips at the resonances and its stretches on the line are largely missing. Each value’s printed cell gives its pixel (column, row) in the page image. The values mapped back through the calibration and drawn on the page images follow the solid line and the R curve in every figure (overlays inspected 2026-10-08).
THE CHECKS (the script fails if one is missed). The Xe step ‘at 1843 A’ (p. 844): the drawn step reads 1843.1 angstrom. McCown et al.’s quotation of McGuire’s Xe value at 193 nm (mccown_1982 Table I, 8 x 10^-32 cm^4 W^-1 circular; ‘linear polarization is ~20 % lower’): alpha hbar omega = 8.23e-50 cm4 s, read 8.36e-50 at 1929.9 angstrom (+1.5 %); R read at 1840-1860 angstrom is 1.15-1.20, so sigma_L is 13-17 % below sigma_C there. The drawn ‘R = 1.5’ line, read on the right axis: Fig. 1 1.57, Fig. 2 1.62-1.65, Fig. 3 1.67-1.71, Fig. 4 1.50-1.52 (margin 15 %). DOUBT: the line and the right axis disagree by 3 to 8 pixels in Figs. 1-3 (R is at most 3/2 by Eqs. 3a-3b, yet Fig. 3’s curve reads up to 1.58 where it meets the line): the R values of Ne, Ar and Kr may be high by up to 5, 10 and 14 %. Whether the cross-section curves share the offset cannot be told from the figures (the left and right axes’ decade ticks agree within 5 pixels, referred to the frame); for Xe, where the line reads 1.51, McCown’s quotation agrees to 1.5 %. The text’s ‘In two-photon ionization, except for Ne, away from a resonance the ratio was R ~ 1.5’ (p. 845): read on the long-wavelength continua, Ar 1.15-1.47 (1100-1400 angstrom), Kr 1.12-1.52 (1250-1600), Xe 1.15-1.38 (1480-1840); the stretches nearest 1.5 touch the line and are not read. DOUBT: the text says Fig. 1 is drawn ‘at 1 A per division near the 3d resonances’ (p. 837); the axis is at 5 angstrom per division there (610-640) and at 1 angstrom per division from 592 to 604 (4d, 5s). The figure is followed.
DIGITISING UNCERTAINTY: sigma_2^C 5 % (one pixel is 0.7-0.9 % at 265-335 pixels per decade; the decade calibration within 3.5 pixels, the frame within 2; the 8-12 pixel line’s centre to a pixel; and on a slope of up to one pixel per column the wavelength uncertainty of 2-3 pixels); R the same, or the R = 1.5 line’s misreading where larger (each dataset’s notes). The paper states no uncertainty; the 25 % match-up differences smoothed over (p. 835) are the author’s indication of the calculation’s.
NOT TAKEN. The three-photon figures (Figs. 5-8, pp. 844-846: sigma_3^C in cm^6 s^2 and R = sigma_3^C / sigma_3^L, with enlarged 4f-4f’ and 5f-5f’ resonance insets on their own scales as dashed curves and circles): not read in this curation (two-photon first); they can be read the same way. Fig. 1’s dashed enlargement of the 3d’’ resonance on its own 0.02-angstrom scale (615.6-615.8 angstrom), and the solid line from 611 to 617 angstrom, which it crosses and meets. Fig. 2’s open circles (the author’s LS-coupling variant of the Ar calculation, about 15 markers from 910 to 1120 angstrom, several touching the curve) and open triangles (Pindzola and Kelly’s dipole-length sigma_2^L, Phys. Rev. A 11, 1543 (1975), converted to sigma_2^C by the author with his own R: reproduced and transformed, not the original). Tables I-IV (level designations, experimental and calculated binding energies below the ion’s 2P3/2 and 2P1/2 limits and their differences Delta, cm-1; the experimental ones from Moore’s tables): binding energies below a limit, not energies above the ground level (level_energy), and the calculated ones are the model’s; the adjustments are described above. Table V: algebraic expressions of R at the three-photon resonances. Table VI: Xe excited-state lifetimes (calculated, with other calculations and measurements quoted): no quantity of the vocabulary holds lifetimes, and they are not two-photon data.
FURTHER TWO-PHOTON DATA CITED: M. S. Pindzola and H. P. Kelly, Phys. Rev. A 11, 1543 (1975) (Ar, many-body perturbation theory, LS coupling; since curated, pindzola_1975); B. Ritchie, Phys. Rev. A 16, 2080 (1977) (ritchie_1977). Not in the library: G. A. Victor, Proc. Phys. Soc. London 91, 825 (1967); K. Aron and P. M. Johnson, J. Chem. Phys. 67, 5099 (1977); F. H. M. Faisal, R. Wallenstein and H. Zacharias, Phys. Rev. Lett. 39, 1138 (1977); the method: E. J. McGuire, Phys. Rev. A 23, 186 (1981), and the detailed expressions in Sandia report SAND80-1974 (unpublished).
Recorded bibliographic identity status: VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
mcguire_1981/fig1_sigma2_Ne#
{
"id": "fig1_sigma2_Ne",
"material": "Ne",
"file": "Ne/mcguire_1981__fig1_sigma2_Ne.csv",
"table": "fig_ce2be8a0b31b",
"digitised": "raster",
"quantity": "multiphoton_ionization_cross_section",
"unit": "cm4 s",
"abscissa_unit": "angstrom",
"use": "check",
"uncertainty": {
"relative": 0.05,
"level": "not stated"
},
"parameters": {
"photons": 2,
"polarization": "circular",
"gauge": "length",
"method": "lowest-order perturbation theory, central potential (Hermann-Skillman approximated by straight-line segments of rV), exact characteristic Green's function, jl coupling, resonances shifted to the experimental levels (E0 adjusted per Green's function and spectral range)",
"definition": "sigma_2 = 4 pi (Delta E / F0)^2 (M_2)^2 in cm^4 s (Eq. 1), Delta E the photon energy in Ry, F0 = 3.22e34 cm^-2 s^-1; the rate per atom W = sigma_2 Phi^2, Phi the photon flux in cm^-2 s^-1"
}
}
Fig. 1 (p. 842), solid line: the two-photon cross section of Ne for circularly polarised light, cm4 s, against the photon wavelength, read from the page image (the record’s notes), 593 to 1120 angstrom: the backgrounds and gentle wings between the 4d’, 4d/4d’, 5s’, 5s, 3d’’/3d/3d’, 4s’/4s, 3s’/3s resonances (5.9e-52 to 1.2e-50), not their peaks or steep flanks; 611-617 angstrom (the dashed 3d’’ enlargement) left out. Above the 3s resonance (750-1150 angstrom) a smooth continuum near 1e-51. 5 %: the digitising uncertainty (the record’s notes); the paper states none.
mcguire_1981/fig1_ratio_Ne#
{
"id": "fig1_ratio_Ne",
"material": "Ne",
"file": "Ne/mcguire_1981__fig1_ratio_Ne.csv",
"table": "fig_ce2be8a0b31b",
"digitised": "raster",
"quantity": "multiphoton_ionization_polarization_ratio",
"abscissa_unit": "angstrom",
"use": "check",
"uncertainty": {
"relative": 0.06,
"level": "not stated"
},
"parameters": {
"photons": 2,
"method": "lowest-order perturbation theory, central potential, exact characteristic Green's function, jl coupling, resonances shifted to the experimental levels; R from Eqs. (3a)-(3b)"
}
}
Fig. 1 (p. 842), crosses joined by a line: R = sigma_2^C / sigma_2^L of Ne against the photon wavelength, read from the page image (the record’s notes), 594 to 1100 angstrom, 0.79 to 1.40 where read. Not read where the curve touches the drawn R = 1.5 line or dives at the resonances (596-599, 605-623 and 635-680 angstrom; the dip-peak-dip structure of 3d’’, 3d, 3d’ that the text describes, p. 837, falls to about 0.4). The R = 1.5 line reads 1.57 on the right axis: the values may be high by up to 5 %. 6 %: the digitising uncertainty and that offset.
mcguire_1981/fig2_sigma2_Ar#
{
"id": "fig2_sigma2_Ar",
"material": "Ar",
"file": "Ar/mcguire_1981__fig2_sigma2_Ar.csv",
"table": "fig_0ad46010a4ff",
"digitised": "raster",
"quantity": "multiphoton_ionization_cross_section",
"unit": "cm4 s",
"abscissa_unit": "angstrom",
"use": "check",
"uncertainty": {
"relative": 0.05,
"level": "not stated"
},
"parameters": {
"photons": 2,
"polarization": "circular",
"gauge": "length",
"method": "lowest-order perturbation theory, central potential (Hermann-Skillman approximated by straight-line segments of rV), exact characteristic Green's function, jl coupling, resonances shifted to the experimental levels (E0 adjusted per Green's function and spectral range)",
"definition": "sigma_2 = 4 pi (Delta E / F0)^2 (M_2)^2 in cm^4 s (Eq. 1), Delta E the photon energy in Ry, F0 = 3.22e34 cm^-2 s^-1; the rate per atom W = sigma_2 Phi^2, Phi the photon flux in cm^-2 s^-1"
}
}
Fig. 2 (p. 842), solid line: the two-photon cross section of Ar for circularly polarised light, cm4 s, against the photon wavelength, read from the page image (the record’s notes), 829 to 1390 angstrom (1.5e-50 to 9.3e-50): the backgrounds and gentle wings between the 4d’’, 4d/6s, 4d’, 3d’’, 5s’, 3d, 5s, 3d’, 4s’, 4s resonances, not their peaks or steep flanks; 950-1000 angstrom (one unchecked division) left out. The open circles (the author’s LS-coupling variant) and triangles (Pindzola and Kelly, converted) are not read; where a circle touches the line the sample is dropped by the run-height rule. 5 % (the record’s notes).
mcguire_1981/fig2_ratio_Ar#
{
"id": "fig2_ratio_Ar",
"material": "Ar",
"file": "Ar/mcguire_1981__fig2_ratio_Ar.csv",
"table": "fig_0ad46010a4ff",
"digitised": "raster",
"quantity": "multiphoton_ionization_polarization_ratio",
"abscissa_unit": "angstrom",
"use": "check",
"uncertainty": {
"relative": 0.1,
"level": "not stated"
},
"parameters": {
"photons": 2,
"method": "lowest-order perturbation theory, central potential, exact characteristic Green's function, jl coupling, resonances shifted to the experimental levels; R from Eqs. (3a)-(3b)"
}
}
Fig. 2 (p. 842), crosses joined by a line: R = sigma_2^C / sigma_2^L of Ar against the photon wavelength, read from the page image (the record’s notes), 830 to 1390 angstrom, 1.04 to 1.48 where read; not read where the curve touches the drawn R = 1.5 line (836-858, 884-1010 with the unchecked 950-1000, and 1080-1160 angstrom). The R = 1.5 line reads 1.62-1.65 on the right axis: the values may be high by up to 10 %. 10 %: that offset with the digitising uncertainty.
mcguire_1981/fig3_sigma2_Kr#
{
"id": "fig3_sigma2_Kr",
"material": "Kr",
"file": "Kr/mcguire_1981__fig3_sigma2_Kr.csv",
"table": "fig_79c7e7519da3",
"digitised": "raster",
"quantity": "multiphoton_ionization_cross_section",
"unit": "cm4 s",
"abscissa_unit": "angstrom",
"use": "check",
"uncertainty": {
"relative": 0.05,
"level": "not stated"
},
"parameters": {
"photons": 2,
"polarization": "circular",
"gauge": "length",
"method": "lowest-order perturbation theory, central potential (Hermann-Skillman approximated by straight-line segments of rV), exact characteristic Green's function, jl coupling, resonances shifted to the experimental levels (E0 adjusted per Green's function and spectral range)",
"definition": "sigma_2 = 4 pi (Delta E / F0)^2 (M_2)^2 in cm^4 s (Eq. 1), Delta E the photon energy in Ry, F0 = 3.22e34 cm^-2 s^-1; the rate per atom W = sigma_2 Phi^2, Phi the photon flux in cm^-2 s^-1"
}
}
Fig. 3 (p. 843), solid line: the two-photon cross section of Kr for circularly polarised light, cm4 s, against the photon wavelength, read from the page image (the record’s notes), 960 to 1600 angstrom (4.0e-50 to 2.4e-49): the backgrounds and gentle wings between the 5d’, 6s/4d, 4d’, 5s’, 5s resonances, not their peaks or steep flanks; 945-960 angstrom (7s, 5d, 6s’, 4d’’ crowded) yields no sample, and 1100-1160 and 1240-1250 angstrom (unchecked divisions) are left out. 5 % (the record’s notes).
mcguire_1981/fig3_ratio_Kr#
{
"id": "fig3_ratio_Kr",
"material": "Kr",
"file": "Kr/mcguire_1981__fig3_ratio_Kr.csv",
"table": "fig_79c7e7519da3",
"digitised": "raster",
"quantity": "multiphoton_ionization_polarization_ratio",
"abscissa_unit": "angstrom",
"use": "check",
"uncertainty": {
"relative": 0.14,
"level": "not stated"
},
"parameters": {
"photons": 2,
"method": "lowest-order perturbation theory, central potential, exact characteristic Green's function, jl coupling, resonances shifted to the experimental levels; R from Eqs. (3a)-(3b)"
}
}
Fig. 3 (p. 843), crosses joined by a line (dashed beyond 1250 angstrom): R = sigma_2^C / sigma_2^L of Kr against the photon wavelength, read from the page image (the record’s notes), 946 to 1560 angstrom, 0.97 to 1.58 where read; not read where the curve touches the drawn R = 1.5 line (950-1044, 1090-1161, 1239-1270, 1300-1360 and 1400-1490 angstrom). The R = 1.5 line reads 1.67-1.71 on the right axis, and values above 1.5 (which Eqs. 3a-3b exclude) are read near it: the values may be high by up to 14 %. 14 %: that offset with the digitising uncertainty.
mcguire_1981/fig4_sigma2_Xe#
{
"id": "fig4_sigma2_Xe",
"material": "Xe",
"file": "Xe/mcguire_1981__fig4_sigma2_Xe.csv",
"table": "fig_b8ffcec227ce",
"digitised": "raster",
"quantity": "multiphoton_ionization_cross_section",
"unit": "cm4 s",
"abscissa_unit": "angstrom",
"use": "check",
"uncertainty": {
"relative": 0.05,
"level": "not stated"
},
"parameters": {
"photons": 2,
"polarization": "circular",
"gauge": "length",
"method": "lowest-order perturbation theory, central potential (Hermann-Skillman approximated by straight-line segments of rV), exact characteristic Green's function, jl coupling, resonances shifted to the experimental levels (E0 adjusted per Green's function and spectral range); autoionising (Beutler) structure above 1843 angstrom neglected",
"definition": "sigma_2 = 4 pi (Delta E / F0)^2 (M_2)^2 in cm^4 s (Eq. 1), Delta E the photon energy in Ry, F0 = 3.22e34 cm^-2 s^-1; the rate per atom W = sigma_2 Phi^2, Phi the photon flux in cm^-2 s^-1"
}
}
Fig. 4 (p. 843), solid line: the two-photon cross section of Xe for circularly polarised light, cm4 s, against the photon wavelength, read from the page image (the record’s notes), 1120 to 1940 angstrom (8.3e-50 to 5.2e-49): the backgrounds and gentle wings between the 6d, 6d’, 7s, 5d, 5d’, 6s’, 6s resonances, not their peaks or steep flanks; 1400-1460 and 1480-1500 angstrom (unchecked divisions) left out. The step at 1843 angstrom (the 2P1/2 channel closing; read 1843.1) drops the curve from 1.13e-49 (1840) to 8.8e-50 (1860); beyond it the Beutler autoionising structure is neglected (p. 844). At 1930 angstrom 8.36e-50, 1.5 % above McCown et al.’s quotation (mccown_1982). 5 % (the record’s notes).
mcguire_1981/fig4_ratio_Xe#
{
"id": "fig4_ratio_Xe",
"material": "Xe",
"file": "Xe/mcguire_1981__fig4_ratio_Xe.csv",
"table": "fig_b8ffcec227ce",
"digitised": "raster",
"quantity": "multiphoton_ionization_polarization_ratio",
"abscissa_unit": "angstrom",
"use": "check",
"uncertainty": {
"relative": 0.05,
"level": "not stated"
},
"parameters": {
"photons": 2,
"method": "lowest-order perturbation theory, central potential, exact characteristic Green's function, jl coupling, resonances shifted to the experimental levels; R from Eqs. (3a)-(3b)"
}
}
Fig. 4 (p. 843), crosses joined by a line: R = sigma_2^C / sigma_2^L of Xe against the photon wavelength, read from the page image (the record’s notes), 1152 to 1860 angstrom, 0.95 to 1.38 where read; not read where the curve touches the drawn R = 1.5 line (1100-1152, 1178-1274 and 1300-1460 angstrom). The R = 1.5 line reads 1.50-1.52 on the right axis. At 1840-1860 angstrom 1.15-1.20, so sigma_L is 13-17 % below sigma_C (McCown et al.: ‘~20 % lower’ at 193 nm). 5 %: the digitising uncertainty.
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.