Damped and thermal motion of laser-aligned hydrated macromolecule beams for diffraction

D. Starodub, R. B. Doak, Kevin Schmidt, Uwe Weierstall, J. S. Wu, John Spence, M. Howells, M. Marcus, D. Shapiro, A. Barty, H. N. Chapman

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17 Scopus citations


We consider a monodispersed Rayleigh droplet beam of water droplets doped with proteins. An intense infrared laser is used to align these droplets. The arrangement has been proposed for electron- and x-ray-diffraction studies of proteins which are difficult to crystallize. This paper considers the effect of thermal fluctuations on the angular spread of alignment in thermal equilibrium, and relaxation phenomena, particularly the damping of oscillations excited as the molecules enter the field. The possibility of adiabatic alignment is also considered. We find that damping times in a high-pressure gas cell as used in x-ray-diffraction experiments are short compared with the time taken for molecules to traverse the beam and that a suitably shaped field might be used for electron-diffraction experiments in vacuum to provide adiabatic alignment, thus obviating the need for a damping gas cell.

Original languageEnglish (US)
Article number244304
JournalJournal of Chemical Physics
Issue number24
StatePublished - Jan 1 2005


ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Starodub, D., Doak, R. B., Schmidt, K., Weierstall, U., Wu, J. S., Spence, J., Howells, M., Marcus, M., Shapiro, D., Barty, A., & Chapman, H. N. (2005). Damped and thermal motion of laser-aligned hydrated macromolecule beams for diffraction. Journal of Chemical Physics, 123(24), [244304]. https://doi.org/10.1063/1.2137313