Abstract
We have successfully determined the internuclear distance of I2 molecules in an alignment laser field by applying our molecular structure determination methodology to an I 2p X-ray photoelectron diffraction profile observed with femtosecond X-ray free electron laser pulses. Using this methodology, we have found that the internuclear distance of the sample I2 molecules in an alignment Nd:YAG laser field of 6 × 1011 W/cm2 is elongated by from 0.18 to 0.30 Å “in average” relatively to the equilibrium internuclear distance of 2.666 Å. Thus, the present experiment constitutes a critical step towards the goal of femtosecond imaging of chemical reactions and opens a new direction for the study of ultrafast chemical reaction in the gas phase.
Highlights
We have applied the ultrafast X-ray photoelectron diffraction (UXPD) method to a simple I2 molecule to determine its structure ‒in other words, its internuclear distance ‒in the alignment-laser field. In this Article, we report on the profile of I 2p photoelectron diffraction from I2 molecules with a higher degree of alignment compared with our previous work[14], which was obtained using X-ray free-electron lasers (XFELs) pulses from SPring-8 Ångström Compact free-electron LAser (SACLA)
A pulsed supersonic molecular beam of sample I2 was introduced into the interaction region between facing velocity-map imaging spectrometers (VMIs) and was intersected by collinear pulsed lasers (Nd:YAG laser and XFEL)[14]
Electrons produced by the XFEL pulses were accelerated towards the one VMI, which was operating in a velocity focusing mode, and detected by a microchannel plate (MCP) detector backed by a phosphor screen
Summary
A fundamental question arises: whether the structure of a molecule in an intense alignment-laser field is the same as that in its ground state or not To answer this question, we have applied the UXPD method to a simple I2 molecule to determine its structure ‒in other words, its internuclear distance ‒in the alignment-laser field. We have applied the UXPD method to a simple I2 molecule to determine its structure ‒in other words, its internuclear distance ‒in the alignment-laser field In this Article, we report on the profile of I 2p photoelectron diffraction from I2 molecules with a higher degree of alignment compared with our previous work[14], which was obtained using XFEL pulses from SACLA. We have established that the internuclear distance of I2 in the laser field is slightly elongated relatively to the equilibrium internuclear distance
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have