Slice imaging and velocity mapping using a single field

Abstract

A 4D wave packet study of the CH3I photodissociation in the A-band. Comparison with femtosecond velocity map imaging experiments J. Chem. Phys. 135, 154306 (2011); 10.1063/1.3650718 Conformer specific dissociation dynamics of iodocyclohexane studied by velocity map imaging J. Chem. Phys. 135, 094312 (2011); 10.1063/1.3628682Determining the CH 3 SO 2 → CH 3 + SO 2 barrier from methylsulfonyl chloride photodissociation at 193 nm using velocity map imagingIn this study we demonstrate that it is possible to perform velocity mapping and slice imaging of charged particle products using a single field ͑two electrodes͒ improving on the multielectrode geometries of the past. The performance of this new geometry is competitive to the multielectrode ones, presently limited by detector "spot" resolution. For imaging both photoelectrons and photofragments a resolution of ϳ1% in velocity is achieved without further software manipulation such as event counting. The advantages of this new design are its ability to focus large volumes, its achromaticity ͑very little sensitivity on photofragment velocities͒, independence of the laser beam position in the field perpendicular to the extraction field, and compactness. Using this new design we have studied the photodissociation dynamics of pyrrole at 243 nm and show that internal conversion of electronically excited state molecules to the ground state is important even at such low excitation energies.

The photodissociation of CH3I in the red edge of the A-band: Comparison between slice imaging experiments and multisurface wave packet calculations

“…We used delayed pulsed extraction slicing 50 in the single field configuration developed by Kitsopoulos and Papadakis and described in detail in Ref. 51. Briefly, the delayed pulsed extraction allows the ion cloud to spread in velocities so that the arrival time of the ion packet at the detector has a width of several hundreds of nanoseconds.…”

Velocity-map imaging at low extraction fields

“…10,11 Alternatively, Papadakis and Kitsopoulos have shown that the arrangement can be simplified using only two specifically shaped electrodes to generate the desired electrostatic lens and a single field. 12 Although differa) j.r.r.verlet@durham.ac.uk.…”

A velocity-map imaging study of methyl non-resonant multiphoton ionization from the photodissociation of CH 3 I in the A-band

“…However, images were also recorded (not shown) using a perpendicular polarization set-up of both lasers in order to check the detector response as well as the possible rotational angular momentum alignment of the fragment. The CH 3 + images are recorded using our VMI apparatus in the single-field configuration [29,30]. [31], prior to extracting the translational energy and angular distributions.…”