eshel_2016 ========== B\. Eshel, C\. A\. Rice and G\. P\. Perram, "Pressure broadening and shift rates for Ar \(s\-p\) transitions observed in an Ar\-He discharge", J\. Quant\. Spectrosc\. Radiat\. Transfer 179, 40\-50 \(2016\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1016/j\.jqsrt\.2016\.03\.006 `__ **Source kind:** measurement **Recorded technique:** Tunable diode laser absorption spectroscopy \(New Focus Velocity 6314, 792\-802 nm, 300 kHz linewidth, wavemeter against a stabilised HeNe to 10 MHz, below saturation\) of the metastable\- and resonance\-level absorption lines 801\.699 nm \(s5 \-\> p8\), 800\.836 nm \(s4 \-\> p6\) and 795\.036 nm \(s3 \-\> p4\) of argon in a 13\.56 MHz capacitively coupled discharge \(10 W, alumina tube 0\.15 in i\.d\., flowing 99\.999 % Ar\-He mixtures of 2\.5, 5, 10 and 25 % Ar\) at 10\-160 Torr total pressure \(tables; 10\-200 Torr in the text\)\. Each absorbance profile is fitted with a Voigt profile, the Doppler width constrained to 888 \+\- 25 MHz \(440 \+\- 20 K, the mean of the unconstrained fits below 60 Torr\); the Lorentzian FWHM and the line centre are fitted linearly against the total pressure\. Uncertainties are the 95 % confidence intervals of the linear fits\. **Materials in structured entries:** Ar **Dataset quantities:** pressure\_line\_coefficient **Contents:** 10 datasets; 0 formulas. Curation notes -------------- J\. Quant\. Spectrosc\. Radiat\. Transfer 179, 40\-50 \(2016\) = PDF pages 1\-11 \(journal page = PDF page \+ 39\)\. Identity checked on the first page \(PDF p\. 1\: journal, volume, pages, title, authors, Air Force Institute of Technology; received 7 December 2015, accepted 1 March 2016, available online 17 March 2016; DOI\) on 2026\-10\-12\. Tables 1 and 2 checked cell by cell against their images\. ONE\-PHOTON 4s\-4p LINES, NOT OEP 8's COHERENCE\. These are one\-photon absorption lines from the 4s levels to the 4p levels, broadened and shifted by an Ar\-He mixture\. OEP 8 needs the dephasing of the ground\-to\-4p two\-photon coherence by argon; the 4s\-4p line width also contains the 4s level's broadening and the Ar\-He mixture's helium part, so nothing for the two\-photon coherence is derived from these values\. LEVELS \(Fig\. 1, Paschen and Racah labels with NIST's energies; NIST Ar\_I\_levels\.tsv\)\. s5 = 4s\[3/2\]2 = 3p5\(2P\*3/2\)4s 2\[3/2\]\* J = 2 \(93143\.76 cm\-1\); s4 = 4s\[3/2\]1 = 3p5\(2P\*3/2\)4s 2\[3/2\]\* J = 1 \(93750\.60\); s3 = 4s'\[1/2\]0 = 3p5\(2P\*1/2\)4s 2\[1/2\]\* J = 0 \(94553\.67\); p8 = 4p\[5/2\]2 = 3p5\(2P\*3/2\)4p 2\[5/2\] J = 2 \(105617\.27\); p6 = 4p\[3/2\]2 = 3p5\(2P\*3/2\)4p 2\[3/2\] J = 2 \(106237\.55\); p4 = 4p'\[3/2\]1 = 3p5\(2P\*1/2\)4p 2\[3/2\] J = 1 \(107131\.71\)\. The upper levels p8 and p6 are two of OEP 8's two\-photon levels \(4p\[5/2\]2 and 4p\[3/2\]2\); p4 is one of baig\_2008's photoionised levels\. The printed wavelengths are NIST's vacuum wavelengths \(801\.6990, 800\.8359, 795\.0362 nm; Ar\_I\_lines\_nir\.tsv; script report\)\. The paper misprints the lines as '794\.036 nm' \(pp\. 47\-49\), '800\.036 nm' \(Fig\. 6 and 10 captions\) and '801\.669' \(p\. 45\)\. WIDTH CONVENTION\. Eq\. \(2\) writes the Lorentzian with \(Delta nu\_L / 2\)^2, so Delta nu\_L is the FWHM in ordinary frequency, and Eq\. \(9\) defines the rate by Delta nu\_L = gamma P; Table 1's heading calls the rate '2 gamma'\. The tabulated values are the slopes of the Lorentzian FWHM \(Fig\. 6, whose caption gives the 10 % row\), so width = fwhm; the '2 gamma' label is the convention in which gamma is the half width\. Eq\. \(10\)\: nu\_c = nu\_0 \+ beta P, beta positive for a blue shift \(Table 2\: 'Negative rates are red\-shifts'\), the vocabulary's sign\. Rates are per Torr of total pressure of the mixture\. TAKEN \(tools/extract/eshel\_2016\.py; Tables 1 and 2, 'This work' rows\)\: broadening\_mix\* and shift\_mix\* for 2\.5, 5, 10 and 25 % Ar in He, rows the three lines \(800\.836 nm not measured at 25 %\), use primary, uncertainties the 95 % confidence intervals as printed\. Inline \(p\. 47 and Fig\. 9 caption\)\: the authors' separation of the broadening into Ar\-Ar and Ar\-He rates by a linear fit in the Ar fraction, gamma = gamma\_Ar f\_Ar \+ gamma\_He \(1 \- f\_Ar\), 'Ar\-Ar rates of 8, 38 and 12 MHz/Torr and Ar\-He rates of 16, 16 and 19 MHz/Torr' \(broadening\_self\_fit, broadening\_He\_fit\), use check\: the authors call it 'an estimate', the Ar\-Ar rates are an extrapolation from 2\.5\-25 % Ar to pure argon, and no uncertainty is given\. No shift separation is given \(the paper says shift rates in a mixture do not add, p\. 49\)\. CHECKED \(2026\-10\-12\)\. The 10 % Ar rows against the abstract and the captions of Figs\. 6 and 7 \(script check\)\. The Ar\-He decomposition against Table 1's Ar\-He literature row \(Copley, ref\. 22, 460 K\)\: 801\.699 nm 16\.40 \+\- 1\.64 against the fit's 16; 795\.036 nm 13\.88 \+\- 1\.39 against 19\. FINDINGS\. The fitted Ar\-Ar rate of the 801\.699 and 795\.036 nm lines \(8 and 12 MHz/Torr at 440 K\) is about half their Ar\-He rate; the 800\.836 nm line \(resonance lower level s4\) has the larger Ar\-Ar rate, 38 MHz/Torr, which the paper ascribes to resonance broadening of s4\. The paper's literature rows of Ar\-Ar broadening at 353\-3900 K, scaled to 440 K by T^\-0\.7, give 9\.6\-14\.9 MHz/Torr for 801\.699 and 795\.036 nm \(fit\: 8 and 12\) and 20\.1\-25\.0 for 800\.836 nm \(fit\: 38\); the authors call the separation 'in good agreement' after scaling\. The Einstein A values used \(p\. 42; 1\.86e7, 4\.90e6, 9\.28e6 s\-1, ref\. 35, '25 %'\) are NIST's \(1\.86e7, 4\.9e6, 9\.3e6\) and are not taken\. NOT TAKEN\. The literature rows of Tables 1 and 2 \(refs\. 21\-24, 27\: Copley and Camm 1974, Copley 1976, Vallee et al\. 1977, Moussounda and Ranson 1987, Aeschliman et al\. 1976\), quoted with the authors' T^\-0\.7 scaling; the Lorentzian and Doppler widths and shift at 100 Torr \(1879 \+\- 2 MHz, 889 MHz, 610\.9 \+\- 0\.6 MHz, p\. 44\); the zero\-pressure widths \(117 \+\- 44 to 227 \+\- 33 MHz\); the line\-centre cross sections \(p\. 43\); the Stark estimates \(p\. 45\); Figs\. 3\-10 \(the rates are printed\); the phase\-changing cross sections of Fig\. 10 \(no quantity\)\. No two\-photon data\. **Recorded bibliographic identity status:** VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- eshel\_2016/broadening\_mix2p5 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "broadening_mix2p5", "material": "Ar", "file": "Ar/eshel_2016__broadening_mix2p5.csv", "table": "tbl_45fc5023b655", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "primary", "uncertainty": { "column": true, "level": "95 % confidence" }, "parameters": { "effect": "broadening", "transition": "the rows: 801.699 nm (s5 -> p8, 4s[3/2]2 - 4p[5/2]2), 800.836 nm (s4 -> p6, 4s[3/2]1 - 4p[3/2]2), 795.036 nm (s3 -> p4, 4s'[1/2]0 - 4p'[3/2]1), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "fwhm", "frequency_variable": "ordinary", "perturber": "Ar-He mixture, 2.5 % Ar in He (rate per unit total pressure)", "temperature_k": 440, "pressure_range": "10-160 Torr", "method": "tunable diode laser absorption in an RF discharge, Voigt fits with the Doppler width fixed (440 K), linear fit against pressure" } } Table 1 \(p\. 47\), 'Pressure broadening rate, 2 gamma \(MHz/Torr\)', row '2\.5% Ar' \(this work\)\: 801\.699, 800\.836 and 795\.036 nm, per Torr of the total pressure of the 2\.5 % Ar in He mixture at 440 \+\- 20 K, 10\-160 Torr\. The Lorentzian FWHM rate in ordinary frequency \(record notes\)\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/broadening\_mix5 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "broadening_mix5", "material": "Ar", "file": "Ar/eshel_2016__broadening_mix5.csv", "table": "tbl_45fc5023b655", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "primary", "uncertainty": { "column": true, "level": "95 % confidence" }, "parameters": { "effect": "broadening", "transition": "the rows: 801.699 nm (s5 -> p8, 4s[3/2]2 - 4p[5/2]2), 800.836 nm (s4 -> p6, 4s[3/2]1 - 4p[3/2]2), 795.036 nm (s3 -> p4, 4s'[1/2]0 - 4p'[3/2]1), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "fwhm", "frequency_variable": "ordinary", "perturber": "Ar-He mixture, 5 % Ar in He (rate per unit total pressure)", "temperature_k": 440, "pressure_range": "10-160 Torr", "method": "tunable diode laser absorption in an RF discharge, Voigt fits with the Doppler width fixed (440 K), linear fit against pressure" } } Table 1 \(p\. 47\), 'Pressure broadening rate, 2 gamma \(MHz/Torr\)', row '5% Ar' \(this work\)\: 801\.699, 800\.836 and 795\.036 nm, per Torr of the total pressure of the 5 % Ar in He mixture at 440 \+\- 20 K, 10\-160 Torr\. The Lorentzian FWHM rate in ordinary frequency \(record notes\)\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/broadening\_mix10 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "broadening_mix10", "material": "Ar", "file": "Ar/eshel_2016__broadening_mix10.csv", "table": "tbl_45fc5023b655", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "primary", "uncertainty": { "column": true, "level": "95 % confidence" }, "parameters": { "effect": "broadening", "transition": "the rows: 801.699 nm (s5 -> p8, 4s[3/2]2 - 4p[5/2]2), 800.836 nm (s4 -> p6, 4s[3/2]1 - 4p[3/2]2), 795.036 nm (s3 -> p4, 4s'[1/2]0 - 4p'[3/2]1), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "fwhm", "frequency_variable": "ordinary", "perturber": "Ar-He mixture, 10 % Ar in He (rate per unit total pressure)", "temperature_k": 440, "pressure_range": "10-160 Torr", "method": "tunable diode laser absorption in an RF discharge, Voigt fits with the Doppler width fixed (440 K), linear fit against pressure" } } Table 1 \(p\. 47\), 'Pressure broadening rate, 2 gamma \(MHz/Torr\)', row '10% Ar' \(this work\)\: 801\.699, 800\.836 and 795\.036 nm, per Torr of the total pressure of the 10 % Ar in He mixture at 440 \+\- 20 K, 10\-160 Torr\. The Lorentzian FWHM rate in ordinary frequency \(record notes\)\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/broadening\_mix25 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "broadening_mix25", "material": "Ar", "file": "Ar/eshel_2016__broadening_mix25.csv", "table": "tbl_45fc5023b655", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "primary", "uncertainty": { "column": true, "level": "95 % confidence" }, "parameters": { "effect": "broadening", "transition": "the rows: 801.699 nm (s5 -> p8, 4s[3/2]2 - 4p[5/2]2), 800.836 nm (s4 -> p6, 4s[3/2]1 - 4p[3/2]2), 795.036 nm (s3 -> p4, 4s'[1/2]0 - 4p'[3/2]1), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "fwhm", "frequency_variable": "ordinary", "perturber": "Ar-He mixture, 25 % Ar in He (rate per unit total pressure)", "temperature_k": 440, "pressure_range": "10-160 Torr", "method": "tunable diode laser absorption in an RF discharge, Voigt fits with the Doppler width fixed (440 K), linear fit against pressure" } } Table 1 \(p\. 47\), 'Pressure broadening rate, 2 gamma \(MHz/Torr\)', row '25% Ar' \(this work\)\: 801\.699 and 795\.036 nm \(800\.836 nm\: '\-'\), per Torr of the total pressure of the 25 % Ar in He mixture at 440 \+\- 20 K, 10\-160 Torr\. The Lorentzian FWHM rate in ordinary frequency \(record notes\)\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/shift\_mix2p5 ~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_mix2p5", "material": "Ar", "file": "Ar/eshel_2016__shift_mix2p5.csv", "table": "tbl_6d2606d4248c", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "primary", "uncertainty": { "column": true, "level": "95 % confidence" }, "parameters": { "effect": "shift", "transition": "the rows: 801.699 nm (s5 -> p8, 4s[3/2]2 - 4p[5/2]2), 800.836 nm (s4 -> p6, 4s[3/2]1 - 4p[3/2]2), 795.036 nm (s3 -> p4, 4s'[1/2]0 - 4p'[3/2]1), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "none", "frequency_variable": "ordinary", "perturber": "Ar-He mixture, 2.5 % Ar in He (rate per unit total pressure)", "temperature_k": 440, "pressure_range": "10-160 Torr", "method": "tunable diode laser absorption in an RF discharge, Voigt fits with the Doppler width fixed (440 K), linear fit against pressure" } } Table 2 \(p\. 49\), 'Pressure shifting rate, beta \(MHz/Torr\)', negative = red, row '2\.5% Ar' \(this work\)\: 801\.699, 800\.836 and 795\.036 nm, per Torr of the total pressure of the 2\.5 % Ar in He mixture at 440 \+\- 20 K, 10\-160 Torr\. The line\-centre shift in ordinary frequency, positive to the blue\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/shift\_mix5 ~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_mix5", "material": "Ar", "file": "Ar/eshel_2016__shift_mix5.csv", "table": "tbl_6d2606d4248c", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "primary", "uncertainty": { "column": true, "level": "95 % confidence" }, "parameters": { "effect": "shift", "transition": "the rows: 801.699 nm (s5 -> p8, 4s[3/2]2 - 4p[5/2]2), 800.836 nm (s4 -> p6, 4s[3/2]1 - 4p[3/2]2), 795.036 nm (s3 -> p4, 4s'[1/2]0 - 4p'[3/2]1), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "none", "frequency_variable": "ordinary", "perturber": "Ar-He mixture, 5 % Ar in He (rate per unit total pressure)", "temperature_k": 440, "pressure_range": "10-160 Torr", "method": "tunable diode laser absorption in an RF discharge, Voigt fits with the Doppler width fixed (440 K), linear fit against pressure" } } Table 2 \(p\. 49\), 'Pressure shifting rate, beta \(MHz/Torr\)', negative = red, row '5% Ar' \(this work\)\: 801\.699, 800\.836 and 795\.036 nm, per Torr of the total pressure of the 5 % Ar in He mixture at 440 \+\- 20 K, 10\-160 Torr\. The line\-centre shift in ordinary frequency, positive to the blue\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/shift\_mix10 ~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_mix10", "material": "Ar", "file": "Ar/eshel_2016__shift_mix10.csv", "table": "tbl_6d2606d4248c", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "primary", "uncertainty": { "column": true, "level": "95 % confidence" }, "parameters": { "effect": "shift", "transition": "the rows: 801.699 nm (s5 -> p8, 4s[3/2]2 - 4p[5/2]2), 800.836 nm (s4 -> p6, 4s[3/2]1 - 4p[3/2]2), 795.036 nm (s3 -> p4, 4s'[1/2]0 - 4p'[3/2]1), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "none", "frequency_variable": "ordinary", "perturber": "Ar-He mixture, 10 % Ar in He (rate per unit total pressure)", "temperature_k": 440, "pressure_range": "10-160 Torr", "method": "tunable diode laser absorption in an RF discharge, Voigt fits with the Doppler width fixed (440 K), linear fit against pressure" } } Table 2 \(p\. 49\), 'Pressure shifting rate, beta \(MHz/Torr\)', negative = red, row '10% Ar' \(this work\)\: 801\.699, 800\.836 and 795\.036 nm, per Torr of the total pressure of the 10 % Ar in He mixture at 440 \+\- 20 K, 10\-160 Torr\. The line\-centre shift in ordinary frequency, positive to the blue\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/shift\_mix25 ~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "shift_mix25", "material": "Ar", "file": "Ar/eshel_2016__shift_mix25.csv", "table": "tbl_6d2606d4248c", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "primary", "uncertainty": { "column": true, "level": "95 % confidence" }, "parameters": { "effect": "shift", "transition": "the rows: 801.699 nm (s5 -> p8, 4s[3/2]2 - 4p[5/2]2), 800.836 nm (s4 -> p6, 4s[3/2]1 - 4p[3/2]2), 795.036 nm (s3 -> p4, 4s'[1/2]0 - 4p'[3/2]1), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "none", "frequency_variable": "ordinary", "perturber": "Ar-He mixture, 25 % Ar in He (rate per unit total pressure)", "temperature_k": 440, "pressure_range": "10-160 Torr", "method": "tunable diode laser absorption in an RF discharge, Voigt fits with the Doppler width fixed (440 K), linear fit against pressure" } } Table 2 \(p\. 49\), 'Pressure shifting rate, beta \(MHz/Torr\)', negative = red, row '25% Ar' \(this work\)\: 801\.699 and 795\.036 nm \(800\.836 nm\: '\-'\), per Torr of the total pressure of the 25 % Ar in He mixture at 440 \+\- 20 K, 10\-160 Torr\. The line\-centre shift in ordinary frequency, positive to the blue\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/broadening\_self\_fit ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "broadening_self_fit", "material": "Ar", "table": "text", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "check", "uncertainty": { "level": "not stated" }, "parameters": { "effect": "broadening", "transition": "the rows: 801.699 nm (s5 -> p8), 800.836 nm (s4 -> p6), 795.036 nm (s3 -> p4), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "fwhm", "frequency_variable": "ordinary", "perturber": "self", "temperature_k": 440, "pressure_range": "10-160 Torr (mixtures of 2.5-25 % Ar)", "method": "linear fit of the mixtures' broadening rates against the Ar fraction (Ar-Ar part)" } } 3 inline points in the source record. p\. 47 and Fig\. 9's caption\: 'Ar\-Ar rates of 8, 38 and 12 MHz/Torr' for 801\.699, 800\.836 and 795\.036 nm, from the linear fit gamma = gamma\_Ar f\_Ar \+ gamma\_He \(1 \- f\_Ar\) to the mixtures' broadening rates \(Table 1, 2\.5\-25 % Ar\); the authors' 'estimate', no uncertainty; an extrapolation to pure argon\. Use check \(record notes\)\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. eshel\_2016/broadening\_He\_fit ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "broadening_He_fit", "material": "Ar", "table": "text", "quantity": "pressure_line_coefficient", "unit": "MHz/torr", "abscissa": "label", "use": "check", "uncertainty": { "level": "not stated" }, "parameters": { "effect": "broadening", "transition": "the rows: 801.699 nm (s5 -> p8), 800.836 nm (s4 -> p6), 795.036 nm (s3 -> p4), vacuum wavelengths", "photons": 1, "frequency_scale": "transition", "width": "fwhm", "frequency_variable": "ordinary", "perturber": "He", "temperature_k": 440, "pressure_range": "10-160 Torr (mixtures of 2.5-25 % Ar)", "method": "linear fit of the mixtures' broadening rates against the Ar fraction (Ar-He part)" } } 3 inline points in the source record. p\. 47 and Fig\. 9's caption\: 'Ar\-He rates of 16, 16 and 19 MHz/Torr' for 801\.699, 800\.836 and 795\.036 nm, from the linear fit gamma = gamma\_Ar f\_Ar \+ gamma\_He \(1 \- f\_Ar\) to the mixtures' broadening rates \(Table 1, 2\.5\-25 % Ar\); the authors' 'estimate', no uncertainty; an extrapolation to pure helium\. Use check \(record notes\)\. One\-photon 4s\-4p lines, not the ground\-to\-4p two\-photon coherence\. 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.