alnaser_2005 ============ A\. S\. Alnaser, M\. Zamkov, X\. M\. Tong, C\. M\. Maharjan, P\. Ranitovic, C\. L\. Cocke and I\. V\. Litvinyuk, "Resonant excitation during strong\-field dissociative ionization", Phys\. Rev\. A 72, 041402\(R\) \(2005\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1103/PhysRevA\.72\.041402 `__ **Source kind:** measurement **Recorded technique:** COLTRIMS of O\+ \+ O\+ pairs from O2 \(p\. 2\)\: a TOPAS optical parametric amplifier pumped by a Ti\:sapphire multipass amplifier \(790 nm, 35 fs, 1\.5 mJ, 1 kHz\), with frequency doubling or sum\-frequency mixing, gives tunable 500\-2300 nm pulses of about 50 fs and up to 100 uJ, focused by an f = 7\.5 cm spherical mirror onto a supersonic O2 jet; ion pairs with zero total momentum selected as O2 2\+ \-\> O\+ \+ O\+, their KER histogrammed\. Intensities 1\.0\-2\.8 x 10^14 W/cm^2 \(Fig\. 2\), 'in the nonsequential regime well below saturation for single ionization of O2' \(p\. 2\); the polarisation is not stated in the text\. **Materials in structured entries:** None recorded. **Dataset quantities:** None recorded. **Contents:** 0 datasets; 0 formulas. Curation notes -------------- Journal pp\. 041402\-1 to \-3 = pdf pages 1\-3\. Identity checked against pdf p\. 1 \(received 3 June 2005; published 11 October 2005\)\. Curated 2026\-10\-09 \(TC\-964\)\. NOTHING IS TAKEN\: no number of a quantity is printed in the text or a table\. The KER bands of O2 2\+ \-\> O\+ \+ O\+ were assigned to states of O2 2\+ in Voss et al\., J\. Phys\. B 37, 4239 \(2004\) \(their ref\. 15, not in the library\), and are shown here only in Figs\. 1\-2; the B 3Pi\_g band is the window 'KER = 10\.5\-12\.7' eV of the ratio's axis label \(Fig\. 2, lower panel\), an integration window, not a KER value\. THE FINDING\. The yield of the B 3Pi\_g band of O2 2\+ relative to all other bands \('Ratio\(KER = 10\.5\-12\.7 / KER all\)', Fig\. 2\) depends resonantly on the photon energy, 'peaking at 1\.4 eV' \(p\. 3; 'around 890 nm' in the abstract\), from about 0\.02 at 2\.25 eV to about 0\.3 near 1\.5 eV \(read from the figure, not taken\)\. The other bands' angular distributions follow molecular ADK with recollision excitation; B 3Pi\_g's does not\. Proposed pathway \(p\. 3\)\: a resonant 3sigma\_g \-\> 1pi\_g excitation of neutral O2 near 8\.6 eV \(six photons at 890 nm; their refs\. 18\-19\), then removal of two electrons\. The intensity differs between wavelengths \(1\.0\-2\.8 I\_0, I\_0 = 10^14 W/cm^2\) and its calibration is not described; the authors 'made our best effort to compare the results at different wavelengths but the same intensity' \(pp\. 1\-2\)\. FIGURES \(not digitised; raster images\)\: Fig\. 2 \(lower panel\), the B 3Pi\_g / all ratio against photon energy at eight wavelengths with error bars and a guiding curve, a fragmentation\_branching\_ratio of O2 2\+ \(channel\: the B 3Pi\_g band; reference\: all O\+ \+ O\+ bands\) against the photon's energy at the stated intensities, worth digitising; Fig\. 2 \(upper panels\), KER spectra at 550\-1500 nm; Fig\. 1, a KER spectrum at 800 nm and about 2 x 10^14 W/cm^2 with angular distributions\. **Recorded bibliographic identity status:** VALIDATED. 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.