tonkyn_1989
===========

R\. G\. Tonkyn, J\. W\. Winniczek and M\. G\. White, "Rotationally resolved photoionization of O2\+ near threshold", Chem\. Phys\. Lett\. 164, 137 \(1989\)

`Source record <https://github.com/LupoLab/optmat/blob/main/src/optmat/data/sources/tonkyn_1989.toml>`__ · :doc:`Catalogue </the-data/sources>` · :doc:`Review register </register>`

DOI: `10\.1016/0009\-2614\(89\)85005\-5 <https://doi.org/10.1016/0009-2614%2889%2985005-5>`__

**Source kind:** measurement

**Recorded technique:** Delayed pulsed\-field ionisation of high Rydberg states \(n \>= 100, within about 10 cm^\-1 of each threshold\) with coherent VUV light \(UV near 308 nm tripled in a pulsed argon jet; bandwidth 2\.1 cm^\-1, about 1e9 photons per pulse\) in a time\-of\-flight photoelectron spectrometer; O2 from a 40 um nozzle 3 cm from the interaction region; field\-ionisation pulse 0\.3\-3 V after 250\-2000 ns delay\. The energy scale was calibrated against the ionisation potential of Xe \(Yoshino & Freeman 1985\) present in trace amounts\. The rotational structure of the X 2Pi\_g \<\- X 3Sigma\_g\- \(0,0\) ionising transition was fitted with Buckingham, Orr & Sichel's rotationally resolved cross sections and the literature rotational and spin\-orbit constants \(Huber & Herzberg\), which 'did not require any refinement' \(pp\. 138\-140\)\.

**Materials in structured entries:** O2

**Dataset quantities:** ionization\_energy

**Contents:** 2 datasets; 0 formulas.

Curation notes
--------------

PDF pages 1\-6 = journal pages 137\-142\. Identity checked on the first page\. Oxygen only\.

THE IONISATION ENERGY \(pp\. 137, 140, 141\)\: the fit gave 'T0 = 97348 \+\- 2 cm^\-1' \(p\. 140\), 'which we define as the energy for the transition X 2Pi\_g, F1\(v = 0, J = 1/2\) \<\- X 3Sigma\_g\-, F2\(v = 0, J = 1\)' \(p\. 141\)\. By the paper's footnote \#1 \(p\. 140\), F1 is the Omega = 1/2 spin\-orbit component of the ion \(K = J \- 1/2\), so the final level is O2\+ X 2Pi\_\(1/2\)g, v\+ = 0, J\+ = 1/2; the initial level is the neutral's F2 \(J = N\) level with J = 1, i\.e\. N = 1\. The confidence level of \+\-2 cm^\-1 is not stated\. In eV \(not printed; hc = 1\.239841984e\-4 eV cm\)\: 97348 cm^\-1 = 12\.069614 eV \(\+\-0\.00025 eV\)\.

OTHER FIT RESULTS \(p\. 140\)\: intensity coefficients \(C1, C2, C3, C4\) = \(0\.16, 1\.0, 0\.87, 0\.86\); rotational temperature 220 \+\- 20 K; effective linewidth 3\.0 \+\- 0\.3 cm^\-1\. The authors say the temperature and C\_i 'cannot be considered to accurately reflect the populations', only 'a qualitative description' \(p\. 141\)\. The M branches require an important l = 3 partial wave \(p\. 141\)\.

THE ACCEPTED VALUE THEN \(pp\. 138, 141\)\: '97362 \+\- 9 cm^\-1 obtained by Samson and Gardner \[16\] from high resolution photoelectron spectroscopy', by modelling the rotational contour of the v\+ = 0 photoelectron band; recorded as a reproduced value\. Tonkyn et al\.'s branch intensities contradict Samson and Gardner's \(P, R\)\:Q = 0 \(p\. 141\)\.

NOT EXTRACTED\: the unlabelled table \(p\. 140, tbl\_3a97762d1a0c\)\: the Delta K branch designations of a 2Pi \<\- 3Sigma ionising transition for each photoelectron l and lambda \(l = 0\: O\-R \(F1'\), P\-S \(F2'\); l = 1\: N\-S, O\-T; l = 2\: M\-T, N\-U; l = 3\: L\-U, M\-V; branches L \.\.\. V are Delta K = \-5 \.\.\. \+5\)\. Branch labels, not values\. The xenon field\-ionisation study \(Fig\. 1\) and the spectra \(Figs\. 2\-3\) are figures only\.

**Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets
--------

tonkyn\_1989/ie\_O2
~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "id": "ie_O2",
     "material": "O2",
     "table": "text",
     "quantity": "ionization_energy",
     "unit": "cm-1",
     "abscissa": "label",
     "use": "primary",
     "parameters": {
       "kind": "adiabatic",
       "final_state": "X 2Pi_(1/2)g (F1, Omega = 1/2), v+ = 0, J+ = 1/2",
       "initial_state": "X 3Sigma_g- F2, v = 0, J = 1 (N = 1)"
     },
     "uncertainty": {
       "column": true,
       "level": "not stated"
     }
   }

1 inline points in the source record.

pp\. 137, 140, 141\: '97348 \+\- 2 cm^\-1, which we define as the energy for the transition X 2Pi\_g, F1\(v = 0, J = 1/2\) \<\- X 3Sigma\_g\-, F2\(v = 0, J = 1\)'\. F1 is Omega = 1/2 \(footnote \#1, p\. 140\)\. Calibrated against the Xe ionisation potential\. = 12\.069614 eV\. Level of \+\-2 not stated\.

tonkyn\_1989/samson\_1975\_O2
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "id": "samson_1975_O2",
     "material": "O2",
     "table": "text",
     "quantity": "ionization_energy",
     "unit": "cm-1",
     "abscissa": "label",
     "use": "reproduced",
     "reproduced_from": [
       "J. A. Samson and J. L. Gardner, Can. J. Phys. 53, 1948 (1975)"
     ],
     "parameters": {
       "kind": "adiabatic",
       "final_state": "X 2Pi_g (v+ = 0)"
     },
     "uncertainty": {
       "column": true,
       "level": "not stated"
     }
   }

1 inline points in the source record.

pp\. 138 and 141\: 'the presently accepted value of 97362 \+\- 9 cm^\-1 obtained by Samson and Gardner \[16\] from high resolution photoelectron spectroscopy', from a rotational\-contour model of the v\+ = 0 band\. The levels it refers to are not stated here\.

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 </register>` for the checks and decisions.