Научный семинар по ядерной физике имени Б.С. Ишханова НИИЯФ МГУ

The understanding of the electronic structure of matter is largely based on studies of the interaction of matter with electromagnetic radiation and on the concurrent development of quantum-mechanical models. Synchrotron radiation is the optimal source of electromagnetic radiation for such studies, covering wavelengths from infrared to hard X-rays.
I will discuss the most significant recent achievements in the field of HAXPES (HArd X-ray PhotoElectron Spectroscopy) on isolated atoms and molecules, and related spectroscopies, using synchrotron radiation as source.
The possibility of conducting hard x-ray photoexcitation and photoionization experiments under state-of-the art conditions in terms of photon and electron kinetic energy resolution has become available only in the last few years. HAXPES has then produced structural and dynamical information at the level of detail already reached in the VUV and soft-x-ray ranges.
A general overview of the results obtained in this newly accessible photon energy range will be presented, which includes: deeper and deeper electronic levels reached by photoionization; shorter and shorter lifetimes of the states produced this way, which allows studying electron and nuclear dynamics on the timescale of femtoseconds (fs, 10-15 s) and even attoseconds (as, 10-18 s); faster and faster Auger electrons; strong interaction between the photoelectron, the Auger electron and the ion left behind; investigation of physical phenomena well-known in the macroscopic world such as recoil and Doppler effects but occurring at the atomic and molecular level; identification of molecular dynamics on the several relaxation steps in cascade following deep core ionization and excitation; characterization of new electronic states with double core vacancies.

Дата события: вторник, 15 Июня, 2021 - 15:00


    Dynamics of atoms and molecules irradiated with tender-to-hard x rays from synchrotron sources
    Автор(ы) доклада: Professor M.N. Piancastelli (Laboratoire de Chimie Physique-Matière et Rayonnement Sorbonne University, Paris, France)