marinero_1982 ============= E\. E\. Marinero, C\. T\. Rettner and R\. N\. Zare, "Quantum\-state\-specific detection of molecular hydrogen by three\-photon ionization", Phys\. Rev\. Lett\. 48, 1323 \(1982\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1103/PhysRevLett\.48\.1323 `__ **Source kind:** measurement **Recorded technique:** \(2 \+ 1\) resonance\-enhanced multiphoton ionisation of H2 through single rotational levels of E,F 1Sigma\_g\+, the two photons from anti\-Stokes orders of a Raman shifter\: a Nd\:YAG\-pumped rhodamine 6G dye laser \(Quanta\-Ray, 568\.7\-577\.5 nm\) frequency doubled, the doubled light and the residual fundamental focused into an H2 Raman cell \(60 cm, 100 psi\), all orders focused by an f = 10 cm MgF2 lens \(the chamber window\) into flowing H2 \(15\-100 mTorr; to above 1 Torr for the O and S branches\), the pairs 3AS \+ 4AS, 3AS \+ 3AS and 2AS \+ 3AS reaching the E,F \- X \(0,0\), \(0,1\) and \(0,2\) bands; ions collected on a coaxial electrode \(1 MOhm, boxcar\); the anti\-Stokes energies measured by pyroelectric joulemeters after a Pellin\-Broca prism; the sample heated to 295\-748 K \(pp\. 1323\-1324\)\. **Materials in structured entries:** None recorded. **Dataset quantities:** None recorded. **Contents:** 0 datasets; 0 formulas. Curation notes -------------- Phys\. Rev\. Lett\. 48\(19\), 1323\-1326 \(10 May 1982\) = PDF pages 1\-4 \(journal page = PDF page \+ 1322\); a scan with a text layer\. Identity checked against the first page \(VOLUME 48, NUMBER 19, PHYSICAL REVIEW LETTERS, 10 MAY 1982; received 26 February 1982; Marinero, Rettner and Zare, Stanford\) on 2026\-10\-09\. The lower half of PDF page 4 is the start of the next Letter in the issue \(P\. Hannaford and G\. W\. Series, on level\-crossing optogalvanic spectroscopy of 89Y, p\. 1326\), which the library's paper\.md appends; it is not part of this paper\. Numbers read on the rendered pages \(pp\. 1323\-1325\) and Table I's image\. NO DATASET\. The paper is a detection method; the numbers it prints are relative signals, others' values or line positions deduced from others' tables\. WHAT THE PAPER ESTABLISHES \(quoted\)\. \(1\) The E,F state 'has a radiative lifetime of 100 \+\- 20 ns' \(p\. 1323, Refs\. 9, 10\: Kligler and Rhodes 1978; kligler\_1980\), quoted\: held as kligler\_1980's tau\_EF\_v2 \(reproduced from the 1978 Letter\); not taken twice\. \(2\) The ion yield in the limit of complete ionisation of the excited molecules \('expected for I \> 10^8 W cm\-2'\), Eq\. \(1\), i\(J''\) = pi alpha E1 E2 N\(0, J''\) / \(2 h c t\_p\), with alpha 'the two\-photon absorption cross section' and 'a calculated value \[12\] for alpha of 1\.6 x 10^\-30 cm4 W\-1 \(for a measured one\-photon laser bandwidth of 0\.92 cm\-1\)', E1 = 13 uJ, E2 = 49 uJ, N\(0, J''\) ~ 2\.2 x 10^14 cm^\-3, t\_p = 2 ns\: about 8\.8 x 10^6 ions per pulse against 8\.4 x 10^6 measured \(an ion current of 1\.35 x 10^\-11 A on Q1\) \(p\. 1324\)\. NOT TAKEN\: alpha is a peak coefficient for one laser bandwidth \(cm4/W, rate alpha I^2 / hbar omega\), not the frequency\-integrated two\_photon\_excitation\_cross\_section \(a conversion needs the line shape\), and it is reproduced from Bischel et al\. \(Ref\. 12 = bischel\_1979, TC\-917\), which prints for H2 E,F \(v = 2\) at 193 nm an estimate of 9 x 10^\-33 cm4/W for a 100 cm^\-1 line \(that record's notes\); scaled inversely with the bandwidth that would be 9\.8 x 10^\-31 at 0\.92 cm^\-1, 0\.6 of the 1\.6 x 10^\-30 quoted here, but the \(0,0\) band at 202 nm is a different transition from the \(2,0\) band at 193 nm, so this is no check\. \(3\) No three\-photon ionisation cross section is printed\: the third photon is assumed to saturate the ionisation \(above\), so the ion signal measures the two\-photon rate\. \(4\) Table I \(p\. 1325, tbl\_7a5fdcf34d41\)\: Q\-branch ion signals normalised to Q0 at 295, 560 and 748 K, the Boltzmann ratios, and their weighted ratio R\_J'' \(Q1 0\.98 \+\- 0\.03, Q2 1\.14 \+\- 0\.05, Q3 1\.07 \+\- 0\.03, Q4 1\.07 \+\- 0\.08, Q5 1\.39 \+\- 0\.2\), the relative two\-photon rotational line strengths of the E,F \- X \(0,0\) Q branch for linear polarisation, compared with Eq\. \(3\) \(Bray and Hochstrasser\) with \(mu\_S / mu\_I\)^2 ~ 1, 'the predominant intermediate state must have Pi rather than Sigma character', the C 1Pi\_u state; the rotational temperatures from Fig\. 3, 291 \+\- 5, 582 \+\- 19 and 730 \+\- 24 K against 295, 560 and 748 K\. NOT TAKEN\: no quantity holds relative rotational line strengths, and they are of interest for diagnostics, not for the gas's response\. \(5\) Two\-photon band ranges, 98 350\-99 156 cm^\-1 \(\(0,0\)\), 94 995\-95 261 \(\(0,1\)\) and 90 646\-91 074 \(\(0,2\)\) \(p\. 1324\), and Fig\. 2's Q\-line positions, Q3 98 829\.31, Q2 98 992\.19, Q1 99 101\.12, Q0 99 156\.76 cm^\-1, 'deduced from the experimental assignments of Dieke' \(Ref\. 11, Crosswhite's edition of Dieke's tables, 1972\)\. NOT TAKEN\: reproduced from tables not in the library; Q0\(0,0\) would be the T0 of E,F \(electronic\_state\_energy, kind T0\), but see the finding\. FINDING \(the E,F energies from Dieke's tables\)\. Q1\(0,0\) = 99 101\.12 cm^\-1 here is 8\.61 cm^\-1 below the EF \(0, N = 1\) \- X \(0, N = 1\) interval 99 109\.731 39\(18\) cm^\-1 of Hannemann et al\. 2006 that liu\_2009 \(TC\-575\) records in its notes \(Table II, \(2\)\); and Q0\(0,0\) = 99 156\.76 is 7\.8 cm^\-1 below the T0 that the band origins in nist\_webbook\_2026 \(TC\-863, Huber and Herzberg\) give, E \-\> B 8961\.23 plus B \-\> X 90 203\.35 = 99 164\.58 cm^\-1\. The Dieke\-based positions printed here are therefore about 8 cm^\-1 low; kligler\_1980's E,F \(v = 2\) levels come from the same tables\. Not resolved here \(Dieke's tables are not in the library\)\. FURTHER DATA CITED\: D\. J\. Kligler and C\. K\. Rhodes, Phys\. Rev\. Lett\. 40, 309 \(1978\), held as kligler\_1978b \(TC\-1043\)\. NOT IN THE LIBRARY\: The Hydrogen Molecule Wavelength Tables of Gerhard Dieke, ed\. H\. M\. Crosswhite \(Wiley, 1972\); R\. G\. Bray and R\. M\. Hochstrasser, Mol\. Phys\. 31, 1199 \(1976\) \(two\-photon rotational line strengths\); J\. B\. Halpern, H\. Zacharias and R\. Wallenstein, J\. Mol\. Spectrosc\. 79, 1 \(1980\)\. In the library\: kligler\_1980 \(Ref\. 10\) and bischel\_1979 \(Ref\. 12\)\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- No datasets are recorded. 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.