Investigation of structural dynamics of substances using ultrafast electron diffraction and microscopy (50th anniversary of the Institute of Spectroscopy, Russian Academy of Sciences)

The structural dynamics of matter, induced by powerful and most often femtosecond laser pulses, is manifested in an’atomic-molecular ‘movie’, a collection of processes, the exploration of which is of immense interest for today's natural sciences. Studying this global phenomenon requires an ultra-high spatio-temporal resolution that involves the development of dedicated research methods. Laser spectroscopy may be applied to determine energy states of samples and track their evolution in time; however, the structural dynamics of matter can only be disclosed from that information by indirect methods. We present here direct techniques for studying laser-perturbed substances in the spatio-temporal continuum where matter is probed with ultrashort electron and X-ray pulses. We also describe the first series of experiments performed with the aid of a femtosecond electron diffractometer and picosecond transmission electron microscope at the Institute of Spectroscopy of the Russian Academy of Sciences based in Troitsk, Moscow.