Science Daily May 20, 2021
It has so far been difficult to gain a more accurate picture of the course of chemical reactions at the atomic level. An international team of researchers (Germany, USA – UC Berkeley, UC San Diego, SLAC National Accelerator Laboratory, France) has shown second harmonic generation on a table-top extreme ultraviolet source. To investigate the surface of titanium sample down to the atomic level they set up a special focusing geometry, consisting of an elliptically shaped mirror to concentrate the laser radiation onto a small area. They focused the radiation with a wavelength of 32.8 nanometres on an ultra-thin titanium foil and analysed its non-linear interaction with the matter particles. With a spectrometer, they separated the radiation resulting from the interaction with the titanium foil and recorded it using a camera. By comparing simulations with the measurement results, they were also able to show that the resulting radiation originates on the surface of the titanium foil and not within the material. The findings open more accessible opportunities for the study of element-specific dynamics in multicomponent systems where surface, interfacial, and bulk-phase asymmetries play a driving role…read more. Open Access TECHNICAL ARTICLEÂ
The linear absorption spectrum from a broadband HHG source of the Ti foil. Credit: Science Advances 19 May 2021: Vol. 7, no. 21, eabe2265Â