1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Correlation between a photoelectron and a fragment ion in dissociative ionization of ethanol in intense near-infrared laser fields
Rent:
Rent this article for
USD
10.1063/1.4805085
/content/aip/journal/jcp/138/20/10.1063/1.4805085
http://aip.metastore.ingenta.com/content/aip/journal/jcp/138/20/10.1063/1.4805085
View: Figures

Figures

Image of FIG. 1.
FIG. 1.

Schematic energy level diagram of CHOH measured from the ground state of neutral CHOH. A thick and open arrow in the upward direction denotes one photon absorption and a thin arrow in the downward direction denotes photoelectron emission. In the early stage of the laser pulse, multiphoton absorption and photoelectron emission proceed, and further photoabsorption can proceed within the same laser pulse to produce electronically excited CHOH. The threshold energies for yielding the respective product ions are shown with short horizontal bars on the right side of the figure.

Image of FIG. 2.
FIG. 2.

Experimental setup for the photoelectron photoion coincidence momentum imaging. The counter-plot of the electric field applied by the electrostatic lenses is drawn. In the top right, the directions of the coordinates (, , and ) are shown.

Image of FIG. 3.
FIG. 3.

(a)–(d) 2D cuts of 3D momentum distributions of product ions with (a) CHOH, (b) CHOH, (c) CHOH, and (d) CH . (e)–(h) 2D sliced images of the 3D momentum distribution of photoelectrons detected in coincidence with (e) CHOH, (f) CHOH, (g) CHOH, and (h) CH . The laser peak intensity and pulse duration are = 9 TW/cm and = 35 fs. The vertical () axis is along the laser polarization direction. The unit of the coordinates is the atomic unit (a.u.) in both electron and ion images. On the top axes in (a)–(d), the velocity unit (km/s) is shown as a reference. An atomic unit of the momentum is equal to 1.198 km/s. In (a)–(d), is defined as | | = ( + ), and the image in the area of < 0 is a mirror image of that in the area of > 0. , , and stand for the momentum of the product ions along the , , and axes (See Fig. 2 ). In (e)–(h), and stand for the momentum of the photoelectrons along the and axes. The pixel size is set to be 3.0 a.u × 3.0 a.u. in (a)–(d) and 0.01 a.u. × 0.01 a.u. in (e)–(h).

Image of FIG. 4.
FIG. 4.

Photoelectron spectra for the formation of CHOH, CHOH, CHOH, and CH (from the top) at the laser peak intensities of = (a) 9, (b) 17, and (c) 23 TW/cm with the pulse duration of = 35 fs. The spectra for the CHOH and CH formation are multiplied by 0.5 and 10, respectively.

Image of FIG. 5.
FIG. 5.

Photoelectron spectra for the formation of CHOH, CHOH, CHOH, and CH (from the top) at the laser peak intensity in the range between = 17 and 19 TW/cm. The laser pulse is positively chirped with the pulse duration of (a) 200 and (b) 800 fs, and negatively chirped with the pulse duration of (c) 200 and (d) 800 fs.

Image of FIG. 6.
FIG. 6.

Energy correlation maps of a photoelectron and a fragment ion detected in coincidence for the formation of (a) CHOH and (b) CH . The laser peak intensity and pulse duration are = 9 TW/cm and = 35 fs. The numbers of the observed events plotted in the maps are 70 857 and 3473 for CHOH and CH , respectively.

Image of FIG. 7.
FIG. 7.

Kinetic energy distributions (circles) of CHOH fragment ion when the photoelectron energies are (a) 0.2, (b) 0.8, and (c) 1.5 eV. These distributions are extracted from Fig. 6(a) and reproduced well by a Boltzmann-type distribution, proportional to exp(− /) (thick gray lines), where is a translational temperature of CHOH. The fitting results are (CHOH) = 462(6), 284(6), and 465(6) K in (a)–(c), respectively.

Image of FIG. 8.
FIG. 8.

Translational temperature of CHOH, (CHOH), as a function of when = 35 fs and = (a) 9, (b) 17, and (c) 23 TW/cm.

Image of FIG. 9.
FIG. 9.

Kinetic energy distributions (circles) of CH fragment ion when the photoelectron energies are (a) 0.2, (b) 0.8, and (c) 1.5 eV. These distributions are extracted from Fig. 6(b) and reproduced well by a Boltzmann-type distribution (see the caption of Fig. 7 ). The fitting results are (CH ) = 1799(104), 2077(151), and 2077(175) K in (a)–(c), respectively.

Image of FIG. 10.
FIG. 10.

Translational temperature of CH , (CH ), as a function of when = 35 fs and = (a) 9, (b) 17, and (c) 23 TW/cm. The large fluctuation in (a) is mainly ascribed to the fact that the number of the accumulated events for the channel yielding CH is not large enough.

Image of FIG. 11.
FIG. 11.

Translational temperature of CHOH ((a) and (b)) and CH ((c) and (d)) as a function of when the pulse duration is 200 fs ((a) and (c)) and 800 fs ((b) and (d)). The laser peak intensity is kept to be in the range between = 17 and 19 TW/cm. Open red circles and solid black squares indicate the results by the positively and negatively chirped pulses, respectively.

Image of FIG. 12.
FIG. 12.

Laser intensity dependence of temperature of (a) CHOH and (b) CH when = 35 fs, and laser pulse duration dependence of temperature of (c) CHOH and (d) CH when the laser peak intensity is kept to be in the range between = 17 and 19 TW/cm. The pulse duration is stretched with the negative (open blue square) and positive (open red circle) chirp rates. The plotted temperatures are obtained through the least-squares fit of the kinetic energy distributions of CHOH and CH integrated for all the range of .

Image of FIG. 13.
FIG. 13.

Yield ratios of the six product ions, CHOH, CHOH, CHOH, CH , CH , and CH , when = 35 fs and = (a) 9, (b) 17, and (c) 23 TW/cm. The ratios are normalized so that the sum of the yields of the six product ions is unity.

Image of FIG. 14.
FIG. 14.

Yield ratios of the six product ions, CHOH, CHOH, CHOH, CH , CH , and CH , when = (a) 35, (b) 200, and (c) 800 fs. The laser intensity is kept to be in the range between = 17 and 19 TW/cm. In (b) and (c), the laser pulse duration is stretched with the negative (black bar) and positive (gray bar) chirp rate. The ratios are normalized so that the sum of the yields of the six product ions is unity.

Loading

Article metrics loading...

/content/aip/journal/jcp/138/20/10.1063/1.4805085
2013-05-22
2014-04-19
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Correlation between a photoelectron and a fragment ion in dissociative ionization of ethanol in intense near-infrared laser fields
http://aip.metastore.ingenta.com/content/aip/journal/jcp/138/20/10.1063/1.4805085
10.1063/1.4805085
SEARCH_EXPAND_ITEM