talebpour_1997

A. Talebpour, S. Larochelle and S. L. Chin, “Dissociative ionization of NO in an intense laser field: a route towards enhanced ionization”, J. Phys. B: At. Mol. Opt. Phys. 30, 1927 (1997)

Source record · Catalogue · Review register

DOI: 10.1088/0953-4075/30/8/010

Source kind: measurement

Recorded technique: Ion yields against peak intensity of NO+, O+, N+, NO2+, O2+ and N2+ from NO in 200 fs (FWHM, transform limited), 800 nm, linearly polarised Ti:sapphire pulses focused with f/50 or f/100 optics (1 m lens) into an ultrahigh-vacuum chamber (2e-9 Torr); time-of-flight mass spectrometer (60 cm drift tube), curves combined from scans at fill pressures 1e-8 to 1e-4 Torr; covariance (triple-coincidence) maps of the fragment pairs over 3000 shots (pp. 1928-1932).

Materials in structured entries: None recorded.

Dataset quantities: None recorded.

Contents: 0 datasets; 0 formulas.

Curation notes

PDF pages 1-13: page 1 is the publisher’s cover sheet, PDF p. 2 = journal p. 1927 (pages cited are journal pages). Identity checked on the first page.

NOTHING IS TAKEN. NO is not a curated species; the paper’s data are NO’s ion yields (Fig. 1) and covariance maps (Figs. 2, 4), figures only, and its model (rescattering, dissociative recombination and enhanced ionisation) gives no rate or parameter of an in-scope gas. The only in-scope statements are qualitative (p. 1930): ‘In other experiments with CO, N2 and O2 it was found that the ratios S(N+)/S(N2+) and S(O+)/S(CO+) are independent of intensity and the ratio S(O+)/S(O2+) shows a slight intensity dependence’, without values.

THE INTENSITY CALIBRATION (pp. 1928-1929), the reason the roadmap asks for this paper (the calibration behind the Laval group’s effective charges, talebpour_1999, and talebpour_1998): ‘The intensity was determined by measuring the laser energy, the pulse width, and the focal spot size’: energy from a 4 % reflection off a wedged beam splitter after the interaction region, on a pyroelectric meter; pulse width from a second-order autocorrelator; the focal spot imaged (after attenuation by reflections from glass plates) with a microscope objective on a CCD camera, a Gaussian profile of roundness 0.95 and 1/e^2 diameter 49 um for the 2 cm beam. ‘We verified our absolute intensity calibration by comparing with the saturation intensity predicted by the ADK formula (Ammosov et al 1986) in the case of helium. As has already been observed (Walker et al 1994), near the saturation region, the experimentally measured He+ signal (using the Ti:sapphire laser) has an excellent overlap with the ion yield predicted by the ADK theory.’ No uncertainty of the intensity is stated. The ions are collected from a region (2 cm openings) shorter than the Rayleigh range (~6 cm for f/100).

ION-SIGNAL CALIBRATION (p. 1930): N = g n = 1.25e17 g int v(t) dt; at 7e13 W/cm^2 and 1e-4 Torr, about 2e8 ions in the collection volume for a signal of 4e-4 V s^-1, so g = 4e-6 and the detection limit 1e-11 V s^-1 is about five ions. The appearance intensity is the lowest intensity giving a detectable signal (1e-11 V s^-1) (p. 1932). The N+ and O+ to NO+ ratios vary as I^1.46 up to 4e13 W/cm^2, then level off (p. 1930).

FIGURES (not digitised): Fig. 1, the NO+, O+, N+, NO2+, O2+, N2+ yields against intensity (with the interaction region’s schematic); Figs. 2 and 4, r^2 covariance maps at 2e13 and 1e14 W/cm^2; Figs. 3 and 5, schematic potential surfaces of NO and NO+.

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 review register for the checks and decisions.