guo_1998#
C. Guo, M. Li, J. P. Nibarger and G. N. Gibson, “Single and double ionization of diatomic molecules in strong laser fields”, Phys. Rev. A 58, R4271 (1998)
Source record · Catalogue · Review register
DOI: 10.1103/PhysRevA.58.R4271
Source kind: measurement
Recorded technique: Single and double ion yields of N2, Ar, O2 and Xe against peak intensity, 2 x 10^13 to 8 x 10^14 W/cm^2: Ti:sapphire laser, 800 nm, 30 fs, 1 kHz, over 400 uJ; linear (LP) and circular (CP) polarisation; on-axis parabolic mirror; base pressure < 5 x 10^-10 torr; ions extracted through a 1 mm pinhole into a time-of-flight mass spectrometer, microchannel plate, individual ion counting (signal kept between 10^-5 and 10^-1 counts/shot by the gas pressure); fragment ions (N+ + N+, O+ + O, O+ + O+) recorded too (p. 2).
Materials in structured entries: O2
Dataset quantities: ionization_model_parameter
Contents: 1 dataset; 0 formulas.
Curation notes#
Journal pp. R4271-R4274 = pdf pages 1-4. Identity checked against pdf p. 1 (C. Guo, M. Li, J. P. Nibarger and G. N. Gibson; received 31 August 1998).
WHY NO YIELDS ARE TAKEN. The ion yields are in figures only, as ion signal in counts/(shot torr) against intensity: Fig. 1 N2+, N2 2+, N+ + N+ and Ar+, Ar2+ (LP and CP); Fig. 2 O2+, O2 2+, O+ + O, O+ + O+ and Xe+, Xe2+ (LP); Fig. 3 O2 and Xe (CP); Fig. 4 the double/single ratios of N2, Ar, O2, Xe (LP). None is printed as a number, and none is digitised. ‘The N2+ data are slightly reduced at the highest intensities due to detector saturation’ (Fig. 1 caption).
CALIBRATION (p. 2). Intensity: ‘The intensity was calibrated by fitting the Ar+ LP ion yield to the ADK model. The rate was integrated over the measured pulse duration and focal volume. The adjustable parameters in the fit are the beam waist, detection efficiency, and extraction pinhole diameter’; ‘The absolute intensity based on fitting the Ar+ ion yield agreed with the intensity calculated from the measured beam-spot size, pulse duration, and energy also to within a factor of 2. All of the other ADK curves (Figs. 1-3) use the experimental parameters determined from the Ar+ LP data.’ So every intensity here is ADK’s Ar+ intensity, and the agreement of Xe and N2 with ADK is relative to Ar. Detection efficiency: ‘independently measured to be 0.5-1 % using correlation techniques’; ‘The fitted detection efficiency agrees with this measured value within a factor of 2’; the electron-multiplier efficiency is taken as proportional to Z/M^(1/2) (Cornaggia et al., ref. 16). Volume: because of the pinhole the volume saturation ‘does not follow the usual I^(3/2) dependency’. Thermal O+ contamination of the O2 2+ signal measured and ‘negligible’ (p. 3).
FINDINGS STATED (numbers in the text). N2 behaves like Ar (similar ionisation potentials) in single, double and nonsequential double ionisation, for LP and CP; N2+ dissociation ‘quite small’ (p. 3). ‘the O2+ LP ion yield is roughly ten times below Xe+ in the unsaturated range of the data’ (p. 3), the same with CP (Fig. 3), so the suppression is not dissociative recombination; ‘the O2+ ion yield can be fit reasonably well to an ADK rate if we use an ionization potential of 15 eV ... this ionization potential falls between the two ionization limits of O2, leading to the X and A state of O2+, 12.06 and 16 eV, respectively’ (pp. 3-4; the dashed curve of Fig. 2): the dataset ip_adk_O2. The ratio N2 2+/N2+ and Ar2+/Ar+ is weakly intensity dependent between 1.2 x 10^14 and 3 x 10^14 W/cm^2 (nonsequential), approaching the sequential yield above 3 x 10^14 W/cm^2 (p. 3); Xe’s NSDI rate is ‘about five times higher’ (Fig. 4, p. 4); O2 shows NSDI ‘with a rate much lower than the other three gases’ (p. 4).
VALUES QUOTED WITHOUT A SOURCE (not taken as data): ionisation potentials (single and double, p. 1): N2 15.58 and 27.12 eV, Ar 15.76 and 27.63, O2 12.06 and 24.14, Xe 12.13 and 21.21; polarizabilities (p. 3): Xe 4.04 x 10^-24 cm^3, O2 1.58 x 10^-24 cm^3.
Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
guo_1998/ip_adk_O2#
{
"id": "ip_adk_O2",
"material": "O2",
"table": "text",
"quantity": "ionization_model_parameter",
"unit": "eV",
"abscissa": "none",
"use": "check",
"parameters": {
"model": "adk",
"parameter": "I_p"
}
}
1 inline points in the source record.
Text pp. 3-4 and Fig. 2 caption (‘The dashed curve fitting the O2+ data uses an ionization potential of 15 eV’): the ionisation potential with which the ADK rate (Ammosov et al. 1986, their ref. 6; the rate integrated over pulse and volume with the parameters of the Ar+ fit) fits the O2+ yield ‘reasonably well’ at 800 nm, 30 fs, linear polarisation. An effective value of the model, not O2’s ionisation energy (12.06 eV, p. 1); the ADK quantum numbers used for O2 are not stated. No uncertainty is stated. It plays the part talebpour_1999’s Z_eff = 0.53 (with 12.55 eV, PPT) plays there: both lower the rate of O2 below that of an atom with its ionisation energy.
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.