wu_2006#
J. Wu, H. Zeng, J. Wang and C. Guo, “Dynamics of triple-ionization-induced dissociation in diatomic molecules in strong fields”, Phys. Rev. A 73, 051402(R) (2006)
Source record · Catalogue · Review register
DOI: 10.1103/PhysRevA.73.051402
Source kind: measurement
Recorded technique: Ti:sapphire laser, 800 nm, 60 fs, about 1.2 mJ, 1 kHz, focused by a thin lens into a chamber at < 5.0 x 10^-10 Torr; linear polarisation parallel to the time-of-flight axis. Ions in a time-of-flight mass spectrometer (1 mm pinholes in the extraction plates), microchannel plate, boxcar ion yields or a multihit time digitiser (100 ps). Dissociation channels separated by ion-ion correlation (their ref. 13, Guo et al. 2000); the kinetic energy release from the flight-time separation of the forward and backward fragment peaks (p. 1-2).
Materials in structured entries: N2, O2
Dataset quantities: kinetic_energy_release
Contents: 2 datasets; 0 formulas.
Curation notes#
Journal pp. 051402-1 to -4 = pdf pages 1-4. Identity checked against pdf p. 1 (received 8 March 2006, published 19 May 2006). Curated 2026-10-09 (TC-959).
NOTATION: N(2,1) is the channel N2+ + N+ (from N2 3+), N(1,1) is N+ + N+ (from N2 2+); O(2,1) and O(1,1) likewise (p. 2).
THE INTENSITIES. Quoted in the text only as positions on Figs. 2-4: the N(2,1)/N(1,1) ratio depends weakly on intensity ‘below the intensity of 2.8 x 10^14 W/cm^2’ and more strongly above it (pp. 2-3); the O(2,1) yield ‘surpasses that of O(1,1) at intensities above 4.0 x 10^14 W/cm^2’ (p. 3). The intensity calibration is not described, and the intensity of the time-of-flight spectra from which the KERs come (Fig. 1) is not stated.
THE KINETIC ENERGY RELEASES (datasets). N(2,1): ‘determined to be 15.0 eV by summing the kinetic energy carried by the corresponding N2+ and N+ ions’ (p. 2), against ‘~26 eV’ expected for a vertical transition (refs. 1-2, soft x-ray and 248 nm) and 12-16 eV in the long-pulse experiments of refs. 3-6. O(2,1): ‘measured to be 13.8 eV [7], which is about 6.0 eV higher than the O(1,1) channel in our experiment’ (p. 3). The citation of Normand et al. 1991 (ref. 7, not in the library) after 13.8 eV leaves open whether the number is this experiment’s or ref. 7’s; the following sentence (the third ionisation at ‘about 2.4 A’, from ref. 7’s method) suggests ref. 7 supplies the method. The O(1,1) KER is thus about 7.8 eV, a difference not printed and not taken. No uncertainty is stated for either value.
THRESHOLDS PRINTED, NOT TAKEN (no quantity holds them as printed): - ‘The possible final excited states ... are N2+(4P) + N+(1S) and N2+(2Po) + N+(3Do), whose threshold energies are about 11.14 and 11.43 eV higher than the ground state of the dissociating channel N2+(2Po) + N+(3P)’ (pp. 2-3). These limits are measured from the ground limit of N2 3+, not from the ground state of a species, which dissociation_energy (kind threshold) requires; they are sums of atomic-ion excitation energies, cited to no source. - ‘the threshold energy for O(2,1) is about 35.12 eV above the O(1,1) channel’ (p. 3): the O(2,1) limit above the O(1,1) limit, the same difficulty. - ‘The ionization potentials obtained by this method in our experiment for N(1,1) and O(1,1) are 46.6 and 40.1 eV, respectively, above the ground states of the neutral molecule’ (p. 3), where the method sums ‘the energy necessary to dissociate the neutral molecule, the energy needed to ionize each atom to its specific charge state, and the released kinetic energy’ (ref. 13). They include the measured KER, so they are not dissociation limits (dissociation_energy) and not onsets (appearance_energy); the dissociation and ionisation energies used are not printed.
FINDINGS STATED: the O(2,1)/O(1,1) ratio falls monotonically with decreasing intensity, so O(2,1) forms through O(1,1) (nonvertically); N(2,1)/N(1,1) depends weakly on intensity below 2.8 x 10^14 W/cm^2, read as a vertical transition to excited N2 3+ limits, and more strongly above (pp. 2-3).
FIGURES (not digitised; raster images): Fig. 1, time-of-flight spectra of N+/N2+ and O+/O2+; Figs. 2 and 3, ion yields of N2+ from N(2,1) and N+ from N(1,1), and of O2+ from O(2,1) and O+ from O(1,1), against intensity; Fig. 4, the ratio curves N(2,1)/N(1,1) and O(2,1)/O(1,1) against intensity, the paper’s main result and a fragmentation_branching_ratio (reference: another channel) against intensity, worth digitising, with the uncalibrated intensity stated.
Recorded bibliographic identity status: VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
wu_2006/ker_N2_N2+N+#
{
"id": "ker_N2_N2+N+",
"material": "N2",
"table": "text",
"quantity": "kinetic_energy_release",
"unit": "eV",
"abscissa": "none",
"use": "primary",
"uncertainty": {
"level": "not stated"
},
"parameters": {
"channel": "N2 3+ -> N2+ + N+",
"kind": "peak",
"state": "N2 3+ (vertical, to N2+(4P) + N+(1S) or N2+(2Po) + N+(3Do) as proposed by the authors)",
"wavelength_nm": 800,
"pulse_fs": 60,
"polarization": "linear"
}
}
1 inline points in the source record.
p. 2 (and p. 3): the total KER of N2 3+ -> N2+ + N+, ‘determined to be 15.0 eV by summing the kinetic energy carried by the corresponding N2+ and N+ ions’, from the flight-time separation of the forward and backward peaks of Fig. 1 (so the peak of the distribution). Intensity of the measurement not stated (the ratio study spans the intensities of Figs. 2-4). No uncertainty stated. The authors assign it to a vertical transition to excited limits about 11 eV above the ground limit (the record’s notes).
wu_2006/ker_O2_O2+O+#
{
"id": "ker_O2_O2+O+",
"material": "O2",
"table": "text",
"quantity": "kinetic_energy_release",
"unit": "eV",
"abscissa": "none",
"use": "check",
"uncertainty": {
"level": "not stated"
},
"parameters": {
"channel": "O2 3+ -> O2+ + O+",
"kind": "peak",
"kind_note": "not stated; taken as the peak of the flight-time spectrum, as for N(2,1)",
"state": "O2 3+ (reached nonvertically through O+ + O+, per the authors)",
"wavelength_nm": 800,
"pulse_fs": 60,
"polarization": "linear"
}
}
1 inline points in the source record.
p. 3: ‘The kinetic energy release of the O(2,1) channel is measured to be 13.8 eV [7], which is about 6.0 eV higher than the O(1,1) channel in our experiment.’ Whether 13.8 eV is this experiment’s or that of ref. 7 (Normand et al., Phys. Rev. A 44, 475 (1991), not in the library) is not clear from the sentence: use = check. Peak or mean not stated. No uncertainty.
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 review register for the checks and decisions.