Is radiation damage the limiting factor in high-resolution single particle imaging with X-ray free-electron lasers?

C Östlin; N Timneanu; C Caleman; A V Martin

doi:10.1063/1.5098309

Is radiation damage the limiting factor in high-resolution single particle imaging with X-ray free-electron lasers?

Struct Dyn. 2019 Aug 20;6(4):044103. doi: 10.1063/1.5098309. eCollection 2019 Jul.

Authors

C Östlin¹, N Timneanu¹, C Caleman¹, A V Martin²

Affiliations

¹ Molecular and Condensed Matter Physics, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
² School of Science, RMIT University, Melbourne, Victoria 3000, Australia.

Abstract

The prospect of single particle imaging with atomic resolution is one of the scientific drivers for the development of X-ray free-electron lasers. The assumption since the beginning has been that damage to the sample caused by intense X-ray pulses is one of the limiting factors for achieving subnanometer X-ray imaging of single particles and that X-ray pulses need to be as short as possible. Based on the molecular dynamics simulations of proteins in X-ray fields of various durations (5 fs, 25 fs, and 50 fs), we show that the noise in the diffracted signal caused by radiation damage is less than what can be expected from other sources, such as sample inhomogeneity and X-ray shot-to-shot variations. These findings show a different aspect of the feasibility of high-resolution single particle imaging using free-electron lasers, where employing X-ray pulses of longer durations could still provide a useful diffraction signal above the noise due to the Coulomb explosion.