Damped and thermal motion of large, laser-aligned molecules in droplet beams

Journal Article · Thu Sep 29 00:00:00 EDT 2005 · Journal of Chemical Physics

OSTI ID:885358

Starodub, D; Doak, B; Schmidt, K; Weierstall, U; Wu, J; Spence, J; Howells, M; Marcus, M; Shapiro, D; Barty, A; Chapman, H

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 high pressure gas cell as used in X-ray diffraction experiments are short compared to 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.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 885358
• Report Number(s): UCRL-JRNL-215872; JCPSA6; TRN: US0603868
• Journal Information: Journal of Chemical Physics, Vol. 123; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
59 BASIC BIOLOGICAL SCIENCES
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALIGNMENT
DAMPING
ELECTRON DIFFRACTION
ELECTRONS
FLUCTUATIONS
LASERS
OSCILLATIONS
PROTEINS
RELAXATION
THERMAL EQUILIBRIUM
WATER
X-RAY DIFFRACTION