gornik_1982 =========== W\. Gornik, E\. Matthias and D\. Schmidt, "Two\-photon excitation of the lowest g states in Xe2\*", J\. Phys\. B\: At\. Mol\. Phys\. 15, 3413\-3422 \(1982\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1088/0022\-3700/15/19/011 `__ **Source kind:** measurement **Recorded technique:** Two\-photon excitation spectra of xenon at 50\-500 Torr over 62 500\-70 200 cm^\-1 \(two\-photon scale; laser 320\-285 nm\) with a frequency\-doubled pulsed dye laser \(UV pulse about 3 ns, bandwidth 25 GHz, 'approximately 20 MW cm^\-2' at the focus, excitation volume about 4 x 10^\-5 cm^3\), linear and circular polarisation; VUV fluorescence \(110\-190 nm, solar\-blind EMR 541 G photomultiplier, photon counting, detected fraction 5 x 10^\-4\), first and second continua separated by a quartz cut\-off filter\. Tuning accuracy 'better than 10 cm^\-1 on the two\-photon scale', intensity scale about 10 % \(p\. 3414\)\. **Materials in structured entries:** Xe **Dataset quantities:** collisional\_quenching\_rate\_coefficient, level\_energy **Contents:** 2 datasets; 0 formulas. Curation notes -------------- J\. Phys\. B\: At\. Mol\. Phys\. 15, 3413\-3422 \(1982\) = PDF pages 2\-11 \(PDF page 1 is the IOP download cover; journal page = PDF page \+ 3411\)\. Identity checked on the first page of the article \(PDF p\. 2\: title, authors, Freie Universität Berlin; received 12 March 1982, in final form 9 June 1982\) on 2026\-10\-09\. The numbers below were read on the rendered pages 3414, 3416 and 3420\. The paper is about the Xe2 g states \(0g\+\(3P1\), 1g\(3P1\), 1g\(3P2\)\); Xe2 is not a material of optmat, so its molecular results are not taken \(band positions 67 450\-69 000 cm^\-1, the polarisation ratios Gamma\_c / Gamma\_p = 0\.4, 1\.50\(20\) and 1\.45\(20\), Figs\. 1\-5, the quoted excimer lifetimes \(0u\+ about 5 ns, 1u about 100 ns\), the vibrational relaxation k = 7 x 10^\-11 cm^3 s^\-1 and the 1u \-\> 0u\+ mixing 4\.6 x 10^\-15 cm^3 s^\-1\)\. THE ATOMIC VALUES \(p\. 3414, 3416\)\. 'The weak single line at 67 073 cm^\-1 shows a linear pressure dependence\. Within the experimental error it coincides with the atomic 3P2 level of Xe I at 67 068 cm^\-1 \(Moore 1958\)'\: the dipole\-forbidden 5p6 1S0 \-\> 5p5 6s 3P2 two\-photon transition \(NIST 5p5\(2P\*3/2\)6s 2\[3/2\]\* J = 2, 67067\.547 cm^\-1\)\. Its rate, from about one count per pulse at 50 Torr, 'W\(5p6 1S0; 5p5 6s 3P2\) = 1 x 10^\-2 s^\-1', 'in error by a factor of three'; with W = sigma^\(2\) I / hbar omega and 'alpha = sigma^\(2\) / I', 'alpha\(5p6 1S0; 5p5 6s 3P2\) = 2 x 10^\-35 cm^4 W^\-1', 'about seven orders of magnitude smaller than for typical dipole\-allowed two\-photon transitions to levels of the 5p5 6p configuration \(Gornik et al 1981, Pindzola et al 1981\)'\. TAKEN \(inline, p\. 3414\)\: the line position, 67 073 cm^\-1, as level\_energy of 6s\[3/2\]2 \(use = check\: tuning accuracy 'better than 10 cm^\-1', held as a bound; NIST 67067\.547, 5\.5 cm^\-1 lower; Moore 67 068\)\. The quoted three\-body rate coefficient of the atomic 3P1 and 3P2 levels, 'both atomic states decay via three\-body collisions with an approximate rate constant of k3 = 5 x 10^\-32 cm^6 s^\-1 \(e\.g\. Bonifield et al 1980\), forming higher vibrational 0u\+\(3P1\) and 1u, 0u\-\(3P2\) states' \(p\. 3420\), as collisional\_quenching\_rate\_coefficient \(order 3, perturber self; use = check, assumed = true\: a quoted model input of the relaxation scheme, Fig\. 6\)\. NOT TAKEN \(no quantity\)\: alpha = 2 x 10^\-35 cm^4 W^\-1 and W = 10^\-2 s^\-1 for 6s\[3/2\]2\. alpha is the rate per atom times hbar omega / I^2 at the 25 GHz laser's line centre, a linewidth\-dependent peak coefficient, not the frequency\-integrated two\_photon\_excitation\_cross\_section; the paper states no line shape \(its Ref\. gornik\_1981 does\: a Gaussian with Delta omega^2 = 2 Delta omega\_L^2 \+ Delta omega\_D^2\), and the transition is not one of TC\-952's dipole\-allowed levels\. Checked\: alpha I^2 / hbar omega at 20 MW cm^\-2 and 298\.2 nm \(half of 67 073 cm^\-1\) is 1\.2 x 10^\-2 s^\-1, the printed W\. FINDINGS \(held records, for Q1 of OEP 8\)\. gornik\_1981 \(TC\-922\)\: its measured 6p rates, 3\.2 x 10^4 \(6p\[1/2\]0\) and 3\.5 x 10^3 s^\-1 \(6p\[3/2\]2\) at 1\.8 MW/cm^2 and 2\.8 GHz, are in this paper's convention alpha = W hbar omega / I^2 = 7\.9 x 10^\-27 and 8\.5 x 10^\-28 cm^4 W^\-1 \(as gornik\_1981's notes compute for 6p\[3/2\]2\), 4 x 10^8 and 4 x 10^7 times this paper's 2 x 10^\-35\: 'about seven orders' holds for 6p\[3/2\]2 \(the bandwidths differ, 2\.8 against 25 GHz, which alone moves the peak coefficient by about 9\)\. No 6p\[1/2\]0 strength is given\. TWO\-PHOTON DATA CITED\: M\. S\. Pindzola, M\. G\. Payne and W\. R\. Garrett, Phys\. Rev\. A 24, 3115 \(1981\) \(Xe 6p two\-photon strengths\), held as pindzola\_1981b\. NOT IN THE LIBRARY\: W\. M\. McClain, J\. Chem\. Phys\. 55, 2789 \(1971\) and D\. L\. Andrews and W\. A\. Ghoul, J\. Chem\. Phys\. 75, 530 \(1981\) \(polarisation ratios\); T\. D\. Bonifield et al\., J\. Chem\. Phys\. 72, 2914 \(1980\) \(Xe excimer kinetics, the k3 above\)\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- gornik\_1982/level\_6s32\_2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "level_6s32_2", "material": "Xe", "table": "text", "quantity": "level_energy", "unit": "cm-1", "abscissa": "label", "use": "check", "uncertainty": { "column": true, "level": "bound" }, "parameters": { "configuration": "5p5.(2P*<3/2>).6s", "term": "2[3/2]*", "j": "2", "method": "two-photon excitation spectrum (frequency-doubled dye laser, 25 GHz), VUV fluorescence; the laser calibrated by a monochromator on atomic lines" } } 1 inline points in the source record. p\. 3414\: 'The weak single line at 67 073 cm^\-1', the dipole\-forbidden two\-photon 5p6 1S0 \-\> 5p5 6s 3P2 line \(NIST 5p5\(2P\*3/2\)6s 2\[3/2\]\* J = 2, 67067\.547 cm^\-1\), at 50\-500 Torr; 'The accuracy of the dye laser tuning was better than 10 cm^\-1 on the two\-photon scale' \(p\. 3414\), held as a bound\. A check\: NIST is 5\.5 cm^\-1 lower, within the bound\. gornik\_1982/k3\_self\_Xe ~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "k3_self_Xe", "material": "Xe", "table": "text", "quantity": "collisional_quenching_rate_coefficient", "unit": "cm6/s", "scale": 1e-32, "abscissa": "label", "use": "check", "reproduced_from": [ "T. D. Bonifield, F. H. K. Rambow, G. K. Walters, M. V. McCusker, D. C. Lorents and R. A. Gutcheck, J. Chem. Phys. 72, 2914 (1980)" ], "uncertainty": { "level": "not stated" }, "parameters": { "perturber": "self", "order": 3, "channel": "Xe2* excimer formation (0u+(3P1) from 3P1; 1u, 0u-(3P2) from 3P2)", "assumed": true, "method": "quoted from Bonifield et al. (1980) as approximate" } } 2 inline points in the source record. p\. 3420\: 'both atomic states decay via three\-body collisions with an approximate rate constant of k3 = 5 x 10^\-32 cm^6 s^\-1 \(e\.g\. Bonifield et al 1980\)', one value for both 3P1 \(NIST 5p5\(2P\*3/2\)6s 2\[3/2\]\* J = 1, 68045\.156 cm^\-1\) and 3P2 \(J = 2, 67067\.547\), forming 0u\+\(3P1\) and 1u, 0u\-\(3P2\) excimers respectively; a quoted, approximate model input of the relaxation scheme \(Fig\. 6\), 50\-500 Torr, room temperature\. 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.