kramer_1985 =========== S\. D\. Kramer, M\. G\. Payne and C\. H\. Chen, "Vacuum\-ultraviolet refractive\-index measurement in a negatively dispersive region of xenon", J\. Opt\. Soc\. Am\. B 2, 1284 \(1985\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1364/josab\.2\.001284 `__ **Source kind:** measurement **Recorded technique:** Phase matching of resonant four\-wave sum mixing, omega\_3 = 2 omega\_1 \+ omega\_2, in Xe\-Ar mixtures \(Oak Ridge\)\: lambda\_1 = 252\.5 nm \(two\-photon resonant with Xe 5p5 6p\[3/2\]2; 0\.2 mJ, 5 ns, about 1e7 W/cm2 at the focus\) and lambda\_2 = 1\.33\-1\.62 um \(second Stokes of a dye laser in a high\-pressure H2 Raman cell\), focused \(f = 40 cm\) into a 15 cm cell; the VUV \(1\-500 nJ, calculated bandwidth 1\.5 cm\-1\) detected by ionisation of NO behind a LiF window\. Xe 10\-150 Torr, Ar 100\-1800 Torr \(capacitance manometer, \+\-0\.1 %\), room temperature\. For each density ratio R = N\(Ar\)/N\(Xe\) the wavelength lambda\_3 of maximum VUV output is found \(\+\-7 cm\-1\), and Eq\. \(1\), n\_3\(Xe\) = lambda\_3 \(alpha R \+ beta\), gives xenon's refractivity per atom at lambda\_3 from argon's and xenon's known indices at the other wavelengths \(alpha, beta; p\. 2\)\. **Materials in structured entries:** Xe **Dataset quantities:** refractivity\_per\_density **Contents:** 1 dataset; 0 formulas. Curation notes -------------- Journal pages 1284\-1286 = PDF pages 1\-3; the PDF is a scan \(one image per page, 400 dpi\)\. Identity checked against the first page\. THE MEASUREMENT \(pp\. 1\-2\)\. Eq\. \(1\)\: n\_3\(Xe\) = lambda\_3 \(alpha R \+ beta\), with alpha = 2\[n\_1\(Ar\) \- n\_2\(Ar\)\]/lambda\_1 \+ \[n\_2\(Ar\) \- n\_3\(Ar\)\]/lambda\_3 and beta = 2\[n\_1\(Xe\) \- n\_2\(Xe\)\]/lambda\_1 \+ n\_2\(Xe\)/lambda\_3; n\_i\(A\) is the 'refractive index per atom' of gas A at lambda\_i \(the mixture's n\_i = 1 \+ N\(Ar\) n\_i\(Ar\) \+ N\(Xe\) n\_i\(Xe\)\), i\.e\. \(n \- 1\)/N in the dilute limit, cm^3\. The phase\-matching condition derives from Delta k = 0 as printed \(reproduced here\)\. With the near\-UV and infrared indices 'known to better than \+\-3 %' and Chashchina's argon VUV index \(other values within about 5 %\), alpha = \-9\.0\(\+\-0\.9\)e\-19 cm^2 and beta = 2\.6\(\+\-0\.1\)e\-18 cm^2 at 116\.23 nm; alpha varies from \-8\.4e\-19 at 117\.02 nm to \-9\.9e\-19 at 115\.24 nm, beta negligibly \(p\. 2\)\. 'The error limits are due almost entirely to the uncertainty in the value for alpha' \(p\. 2\)\: a common \(systematic\) error, since alpha rests on argon's index at lambda\_3\. The package reproduces alpha and beta independently from fit/Ar and fit/Xe \(TC\-713\)\: alpha = \-1\.019e\-18, \-9\.32e\-19, \-8\.72e\-19 cm^2 at 115\.24, 116\.23, 117\.02 nm \(3\-4 % more negative than printed, within the \+\-10 %\), beta = 2\.56e\-18 \(1\.4 % below\)\. Checks made by the authors \(p\. 2\)\: Xe2 is below 0\.12 % of the atoms and no dimer band lies in the region; lambda\_3 did not change with the Xe pressure at fixed R\: R = 4\.00, 115\.41 \+\- 0\.01 nm \(Xe 50\-150 Torr\); R = 40\.0, 116\.94 \+\- 0\.01 nm \(Xe 10\-40 Torr\); R = 9\.11, '106\.23 \+\- 0\.01 nm' at 150 and 12\.4 Torr and '106\.28' at 0\.99 Torr, where Eq\. \(1\) no longer holds\. 106\.23 nm is outside the tuning range \(115\-117 nm\) and must be 116\.23 nm, the centre of the range where alpha and beta are quoted \(the page image prints '106\.23'\)\. No change with laser intensity \(excited Xe below 0\.1 %\)\. Fig\. 2's two tuning curves \(60 Torr Xe with 340 and 550 Torr Ar, R = 5\.67 and 9\.17\) peak near 116\.04 and 116\.49 nm \(read by eye from its top axis\)\: the second disagrees with the text's R = 9\.11 at 116\.23 nm \(below\)\. DATASET\: fig3\_Xe, the 26 measured points of Fig\. 3 \('The refractive index per xenon atom', cm^3, all negative\), read from the page image by data rule 8 \(TC\-699; the extraction script's docstring gives the calibration and the rule\), use check\: the paper prints no n\_3 value, only the three \(R, lambda\_3\) pairs above\. The sigma column is the paper's uncertainty, 0\.1 \|n\_3 \- lambda\_3 beta\| \(alpha's 10 % through Eq\. \(1\)\), combined with 2 % for the reading; the upper ends of the error bars drawn at 115\.23, 115\.41 and 115\.81 nm agree with it to 1\-9 % \(the script fails beyond 15 %\)\. The overlay of the 26 extracted centres on the page image matches every marker \(inspected 2026\-09\-29\)\. It is mostly common to all points\. The wavelength's own uncertainty, \+\-7 cm\-1 \(\+\-0\.0094 nm\), is not in the sigma\: near 117\.0 nm it moves n\_3 by 20 % or more\. The state is nominal \(0 degrees C, 1 atm\), as for the other per\-atom values \(mahon\_1979, ferrell\_1987\)\: the reduction then adds a Lorentz\-Lorenz factor of at most 0\.8 % \(at 117\.03 nm, n \- 1 = \-0\.046 at that density\), which the paper's linear definition does not have\. CHECKED against the text\: the pairs R = 4\.00 at 115\.41 nm and R = 40\.0 at 116\.94 nm with the printed alpha \(interpolated\) and beta give \-1\.498e\-23 and \-3\.654e\-22, 2\.4 % and 0\.8 % from the figure interpolated there \(\-1\.463e\-23, \-3\.684e\-22; the script fails beyond 6 %\)\. R = 9\.11 at 116\.23 nm gives \-6\.51e\-23, 23 % more negative than the figure's point at 116\.229 nm \(\-5\.28e\-23\), 1\.5 of its sigma; Fig\. 2's R = 9\.17 at 116\.49 nm gives \-6\.37e\-23, against the figure's \-7\.12e\-23 there\. The paper's R = 9\.11 wavelength \(or R\) may be misprinted beyond the '106'; it is not used\. NOT TRANSCRIBED\: Fig\. 2 \(the two tuning curves\: VUV energy per pulse against the dye wavelength, raster\); Fig\. 3's curve \(Mahon's semiempirical calculation, unpublished details; 'A recent calculation by Payne gives a similar result'\); Fig\. 1 \(the level scheme\)\. The paper says the difference between the calculation and the points at short wavelength arises because 'the discrete and continuum contributions to the refractive index are almost equal in magnitude but opposite in sign' there \(p\. 3\), and that the points agree with Ferrell's then\-unpublished nonlinear measurements \(ferrell\_1987 prints no xenon refractivity in this region\)\. THE REGION\. The points lie on the short\-wavelength side of the Xe 5p5 7s\[3/2\]1 line \(117\.04 nm; arrow in Fig\. 3\), which dominates near 117 nm \(n\_3 = \-1\.7e\-21 cm^3 at 117\.03 nm, n \- 1 = \-0\.046 at 1 atm\), above the 5d\[3/2\]1 line \(119\.20 nm\) whose strength makes the index negative\: beyond xenon's first resonance, far outside fit/Xe's range \(148 nm and longer\) and between lines of euv/Xe \(TC\-713\)\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- kramer\_1985/fig3\_Xe ~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "fig3_Xe", "material": "Xe", "file": "Xe/kramer_1985__fig3_Xe.csv", "table": "fig_26507279fdf6", "digitised": "raster", "quantity": "refractivity_per_density", "unit": "cm3", "abscissa_unit": "nm", "wavelength_medium": "vacuum", "state": "1atm_0C", "density": "unknown", "use": "check", "uncertainty": { "column": true, "level": "not stated" }, "parameters": { "beyond_resonance": true } } Fig\. 3 \(p\. 3\)\: n\_3\(Xe\), the refractivity per atom in the dilute limit \(cm^3, negative\), 115\.23\-117\.03 nm, read from the page image \(the extraction script\)\. Beyond the first resonance; negative\. Sigma\: the paper's alpha uncertainty through Eq\. \(1\) with 2 % for the reading \(the record's notes\); the wavelength's \+\-7 cm\-1 is not included\. 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.