dura_2012#
J. Dura, A. Grün, P. K. Bates, S. M. Teichmann, T. Ergler, A. Senftleben, T. Pflüger, C. D. Schröter, R. Moshammer, J. Ullrich, A. Jaroń-Becker, A. Becker and J. Biegert, “Wavelength Dependence of the Suppressed Ionization of Molecules in Strong Laser Fields”, J. Phys. Chem. A 116, 2662-2668 (2012)
Source record · Catalogue · Review register
DOI: 10.1021/jp207257j
Source kind: measurement
Recorded technique: Reaction microscope (pp. 2663-2664): the laser ‘focused by a spherical on-axis mirror (f = 50 mm) onto a low density supersonic gas-jet target (~1 x 10^11 atoms/cm3)’, 30 um nozzle, 300 kPa stagnation pressure, skimmers of 200 and 400 um, background 7 x 10^-8 Pa; ‘A mass flow controller is used to guarantee the same gas density in the jet for the four different gases used’. Ions and electrons extracted by E ~ 3 V/cm and B ~ 0.5 mT onto chevron MCP detectors (80 mm, delay-line anodes), ‘The solid angle acceptance for ions and electrons is nearly 4 pi’; ions counted individually, ‘single ionization yield values ... obtained by integration of the corresponding TOF ion signals over the exposure time, which could vary from 2 x 10^3 to 4 x 10^3 laser shots’ (p. 2664). Each gas measured on its own (Ar, N2, Xe, O2), not in a mixture. Laser (p. 2663): ‘The Ti:sapphire system delivers 25 fs, 7 mJ pulses centered at 0.78 um with a repetition rate of 3 kHz’; the longer wavelengths from an OPA (Light Conversion He-TOPAS), signal 1.2-1.5 um and idler 1.7-2.5 um, ‘temporally characterized by a home-build second harmonic generation FROG (SHG-FROG) system’. The OPA pulses’ durations and the laser polarisation are not stated (the S-matrix theory is for ‘a linearly polarized strong laser field’, p. 2663).
Materials in structured entries: N2, O2
Dataset quantities: ionization_yield_ratio
Contents: 2 datasets; 0 formulas.
Curation notes#
J. Phys. Chem. A 116, 2662-2668 (2012), PDF pages 1-7 = journal pp. 2662-2668; published online 23 November 2011 (‘Published: November 23, 2011’, received July 29, revised October 18, 2011), in the 2012 issue (the PDF’s running head ‘J. Phys. Chem. A 2012, 116, 2662-2668’): the id uses the print year 2012, the library directory 2011. Identity checked on PDF p. 1 on 2026-10-01: ‘Wavelength Dependence of the Suppressed Ionization of Molecules in Strong Laser Fields’, J. Dura et al., ICFO, MPI fur Kernphysik, JILA; Special Issue Femto10.
WHAT IS MEASURED. ‘the experimental single ionization yields of Ar, N2, Xe, and O2 measured at four different wavelengths from 0.8 to 1.5 um’ (p. 2664), and their ratios O2/Xe and N2/Ar, Fig. 4 (p. 2665): ‘I = 3 x 10^13 W/cm2 experimental results ... Dots: experimental results (gray diamonds, O2/Xe ratio; black circles, N2/Ar ratio); error bars, standard deviation. Open dots: experimental results from literature’ (the caption). The figure’s axis is ‘ratio of signals’.
DETECTION EFFICIENCY (detection_correction = “Z/sqrt(M)”). ‘The electron multiplier efficiency of the ions’ MCP is proportional to Z/M^1/2, [ref. 48: C. Cornaggia et al., Phys. Rev. A 44, 4499 (1991)] where Z is the charge and M is the mass of the ion. Because the aim of the experiment is a comparison between ions with different masses, this factor needs to be taken into account in the final single ionization yield values’ (p. 2664). So the ratios are corrected for a mass-dependent efficiency, as Guo et al.’s and unlike DeWitt et al.’s (dewitt_2001, ref. 19 there: the correction ‘effectively reduced their O2:Xe ionization ratio by a factor of 2’). Not printed here, computed: dividing each yield by an efficiency ~ M^-1/2 lowers O2+/Xe+ by (M_Xe/M_O2)^1/2 = (131/32)^1/2 = 2.0 and N2+/Ar+ by (40/28)^1/2 = 1.2 against the uncorrected counts.
INTENSITY (model-tied). ‘The intensity is calibrated by fitting the Xe+ ionization yield at different intensities of the fundamental Ti:sapphire output, to experimental and calculated ionization yields of Xe+ under similar conditions and published elsewhere. [ref. 12, Guo et al., printed ‘Phys. Rev. Lett. 1998, 58, R4271’] Knowing pulse duration and laser power, the final laser intensity on target can be set equal for the whole range of wavelengths studied’ (p. 2664). The 3 x 10^13 W/cm2 is thus tied to Guo et al.’s Xe+ yields (measured and calculated) at 0.78 um and carried to the OPA wavelengths by the pulses’ durations and powers (neither printed). No uncertainty is stated.
WAVELENGTHS. Read from the figure: 800, 1300, 1400 and 1500 nm (O2/Xe has no 1500 nm point). The 0.8 um points are those of the Ti:sapphire fundamental, ‘centered at 0.78 um’ (p. 2663), drawn at 800 nm (on the 800 nm tick). Pulse duration: 25 fs at 0.78 um; at the OPA wavelengths not stated.
EXTRACTED (2026-10-01) by tools/extract/dura_2012.py from the image of Fig. 4 (1659 x 1004 pixels, lossless grey), whose docstring describes the reading. The ratio axis from 29 ticks (3 to 0.002), the wavelength axis from 4 (800, 900, 1000 and 2000 nm: only 1000 is labelled; the four lying on one log scale within 0.11 pixel checks the reading of the others); every tick within 0.16 pixel of the fitted scales. One pixel is 0.95 % of the ratio and 0.09 % of the wavelength.
CHECKS. (1) The text: ‘The O2/Xe single ionization ratio increases from ~0.1 to ~0.3 within the wavelength range 0.8-1.5 um, which corresponds to an increase of more than a factor 2’ (p. 2665): the points are 0.115, 0.239 and 0.273 at 0.8, 1.3 and 1.4 um (a factor 2.4); the figure has no O2/Xe point at 1.5 um. ‘Over the whole range of wavelengths the experimental N2/Ar ratio is close to 1 and varies between 0.8 to 1.4 um by less than 20%’ (p. 2665): the points are 0.711, 0.714 and 0.889 at 0.8, 1.3 and 1.4 um (the largest 25 % above the smallest, 11 % about their mean), and 0.500 +- 0.330 at 1.5 um. (2) The bars are symmetric in the ratio (standard deviations): for the five read at both ends the upper half over the lower is 0.94-1.03 in the ratio. (3) At 1.5 um the N2/Ar bar’s upper cap lies on the N2/Ar curve and is not read; the lower half mirrored puts it at row 154.7, where the cap’s rows (153-156) merge with the curve. (4) The extracted points and bar ends drawn on the image and inspected on 2026-10-01: each marker’s centre on the marker, the ends on the caps (at 0.8 um the lower caps are drawn over Guo et al.’s open symbols, and read there).
Recorded bibliographic identity status: VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
dura_2012/fig4_O2_Xe#
{
"id": "fig4_O2_Xe",
"material": "O2",
"file": "O2/dura_2012__fig4_O2_Xe.csv",
"table": "fig_13703c126cd6",
"digitised": "raster",
"quantity": "ionization_yield_ratio",
"unit": "1",
"abscissa": "wavelength",
"abscissa_unit": "nm",
"use": "check",
"uncertainty": {
"column": true,
"relative": 0.01,
"level": "1 sigma"
},
"parameters": {
"companion": "Xe",
"intensity_W_cm2": 30000000000000.0,
"polarization": "not stated",
"detection_correction": "Z/sqrt(M)",
"detection_correction_note": "'The electron multiplier efficiency of the ions' MCP is proportional to Z/M^1/2 ... this factor needs to be taken into account in the final single ionization yield values' (p. 2664, ref. 48)",
"intensity_calibration": "Xe+ yield fitted to Guo et al.'s measured and calculated Xe+ yields at the fundamental; carried to the OPA wavelengths by duration and power; no uncertainty stated",
"pulse_fs_note": "25 fs at 0.78 um (the 800 nm point); the OPA pulses' durations not stated",
"mixture": false
}
}
Fig. 4, p. 2665, gray diamonds: the O2+/Xe+ single-ionisation yield ratio at 3 x 10^13 W/cm2 against the wavelength, 3 points at 800, 1300 and 1400 nm, ratio 0.115, 0.239 and 0.273, read from the image (the record’s notes). sigma: half the bar, ‘standard deviation’ (0.042-0.094). Corrected for an MCP efficiency ~ Z/M^1/2 (the record’s notes). The intensity is tied to Guo et al.’s Xe+ yields. 1 %: the digitising (the centre to half a pixel, 0.95 % of the ratio per pixel). The text: ‘increases from ~0.1 to ~0.3 within the wavelength range 0.8-1.5 um’.
dura_2012/fig4_N2_Ar#
{
"id": "fig4_N2_Ar",
"material": "N2",
"file": "N2/dura_2012__fig4_N2_Ar.csv",
"table": "fig_13703c126cd6",
"digitised": "raster",
"quantity": "ionization_yield_ratio",
"unit": "1",
"abscissa": "wavelength",
"abscissa_unit": "nm",
"use": "check",
"uncertainty": {
"column": true,
"relative": 0.01,
"level": "1 sigma"
},
"parameters": {
"companion": "Ar",
"intensity_W_cm2": 30000000000000.0,
"polarization": "not stated",
"detection_correction": "Z/sqrt(M)",
"detection_correction_note": "'The electron multiplier efficiency of the ions' MCP is proportional to Z/M^1/2 ... this factor needs to be taken into account in the final single ionization yield values' (p. 2664, ref. 48)",
"intensity_calibration": "Xe+ yield fitted to Guo et al.'s measured and calculated Xe+ yields at the fundamental; carried to the OPA wavelengths by duration and power; no uncertainty stated",
"pulse_fs_note": "25 fs at 0.78 um (the 800 nm point); the OPA pulses' durations not stated",
"mixture": false
}
}
Fig. 4, p. 2665, black circles: the N2+/Ar+ single-ionisation yield ratio at 3 x 10^13 W/cm2 against the wavelength, 4 points at 800, 1300, 1400 and 1500 nm, ratio 0.711, 0.714, 0.889 and 0.500, read from the image (the record’s notes). sigma: half the bar, ‘standard deviation’: at 1400 nm empty (the caps lie on the marker and on the N2/Ar curve, not read); at 1500 nm the lower half-bar’s length (0.330; the upper cap lies on the curve). Corrected for an MCP efficiency ~ Z/M^1/2. The intensity is tied to Guo et al.’s Xe+ yields. 1 %: the digitising (the centre to half a pixel, 0.95 % of the ratio per pixel). The text: ‘close to 1 and varies between 0.8 to 1.4 um by less than 20%’ (the points: 25 % between the extremes).
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.