Studying femtosecond dynamics of Xray-matter interaction
Title: Studying femtosecond dynamics of Xray-matter interaction
DNr: NAISS 2024/5-140
Project Type: NAISS Medium Compute
Principal Investigator: Carl Caleman <>
Affiliation: Uppsala universitet
Duration: 2024-05-01 – 2025-05-01
Classification: 10302


Radiation damage occurs as a direct consequence of the interplay between radiation with matter via photoelectric effect or Compton scattering. Within femtoseconds after irradiation, the geometrical disturbances in the molecular system may cause disorder, bond breaking or ejection of fragments. Depending on the conditions, photons can drive atoms in the material to highly excited states ejecting photoelectrons that cause further damage. At extreme incident x-ray intensities, matter can reach a high energy density state known as warm dense matter. In this work, we would like to study the transition from the ground state to the excited state. Since intra atomic absorption of radiation leads to unique macromolecular deterioration processes spanning over many degrees of freedom, theoretical modeling becomes challenging. The need to incorporate quantum-mechanical effects on equal footing as taking into account the macromolecular motion demands both accuracy and computational efficiency. Likewise, experimental interpretation of fragmentation measurements on these systems are challenging to tackle, especially as the molecular systems become large and thus the fragmentation dynamics expand in complexity. The aims of this project are: i) develop novel simulation tools, ii) get a better understanding of the relevant physical processes, and iii) development of database with classification and structure determination within SPI.