Dynamics in a cluster under the influence of intense femtosecond hard x-ray pulses

In this paper we examine the behavior of small cluster of atoms in a short (10-50 fs) very intense hard x-ray (10 keV) pulse. We use numerical modeling based on the non-relativistic classical equation of motion. Quantum processes are taken into account by the respective cross sections. We show that there is a Coulomb explosion, which has a different dynamics than one finds in classical laser driven cluster explosions. We discuss the consequences of our results to single molecule imaging by the free electron laser pulses.Comment: 14 pages, 13 figure

Atomistic three-dimensional coherent x-ray imaging of nonbiological systems

We computationally study the resolution limits for three-dimensional coherent x-ray diffractive imaging of heavy, nonbiological systems using Ar clusters as a prototype. We treat electronic and nuclear dynamics on an equal footing and remove the frozen-lattice approximation often used in electronic damage studies. We explore the achievable resolution as a function of pulse parameters (fluence level, pulse duration, and photon energy) and particle size. The contribution of combined lattice and electron dynamics is not negligible even for 2 fs pulses, and the Compton scattering is less deleterious than in biological systems for atomic-scale imaging. Although free-electron scattering represents a significant background, we find that recovery of the original structure is in principle possible with 3 °A resolution for particles of 11 nm diameter