Ultrafast streak camera system for mapping atomic motions with ultrabright electrons

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The PI's group has achieved the fundamental space-time limit to imaging chemistry and has unearthed the basic physics that leads to the reduction in dimensionality in the transition state region that makes chemistry a transferable concept. This long held dream experiment in chemistry was achieved through the development of ultrabright electron sources capable of literally lighting up atomic motions in real time. This ultrabright electron source depends on the use of photo injection using femtosecond lasers for both triggering the chemistry of interest and in generating perfectly timed femtosecond electron probe pulses. The requested rf components and laser system for the ultrafast streak camera will make it possible to employ a single long electron pulse (a few picoseconds) to encode the entire time-varying structural information after photoexcitation in a single shot, i.e., single shot full molecular movies. The time resolution will be in the 10 fs domain, which is sufficient and along with the dramatic increase in signal to noise ratio will make it possible to directly observe the effect of changes in electron distribution with excitation faster than nuclear motions. This observation provides the electron density gradients or forces responsible for collapsing the enormous number of possible nuclear permutations and fluctuations to just a few key reaction modes. We have the opportunity to separate the electronic and nuclear degrees of freedom to come to a full understanding of the mechanism leading to the enormous reduction in dimensionality responsible for the generalized properties for the different classes of reaction mechanisms. The requested instrumentation holds the promise to reveal the physics that has enabled chemistry to scale in complexity all the way to biological systems and makes chemistry a transferrable concept. The requested instrumentation is essential to enter this new domain in space-time resolution, and equally important to achieve sensitivity, for observing the very essence of chemistry. It should be noted that the PI has transitioned back to the University of Toronto in 2020 after successfully co-founding a new Max Planck Institute in Hamburg Germany and the Centre for Ultrafast Imaging for the University of Hamburg. His secondment to the Max Planck from 2010 to 2020 was part of a research partnership based on the above research program. It was not possible to move the needed laser equipment in the labs the PI developed in Hamburg due to Max Planck policies on retaining equipment for internal use. Without the requested equipment, there is no prospect for advancing the PI's program to realize this grand objective to directly imaging the fundamental driving forces for chemistry.