Femtosecond time resolution in x-ray diffraction experiments

AUTOR(ES)

Neutze, Richard

FONTE

The National Academy of Sciences of the USA

RESUMO

This paper presents the theoretical background for a synthesis of femtosecond spectroscopy and x-ray diffraction. When a diffraction quality crystal with 0.1–0.3 mm overall dimensions is photoactivated by a femtosecond laser pulse (physical length = 0.3 μm), the evolution of molecules at separated points in the crystal will not be simultaneous because a finite time is required for the laser pulse to propagate through the body of the crystal. Utilizing this lack of global crystal synchronization, topographic x-ray diffraction may enable femtosecond temporal resolution to be achieved from reflection profiles in the diffraction pattern with x-ray exposures of picosecond or longer duration. Such x-ray pulses are currently available, and could be used to study femtosecond reaction dynamics at atomic resolution on crystals of both small- and macromolecules. A general treatment of excitation and diffraction geometries in relation to spatial and temporal resolution is presented.

Documentos Relacionados

• Microtubule structure at low resolution by x-ray diffraction.
• Molecular structures from femtosecond x-ray pulses
• Crystal structure determination of thymoquinone by high-resolution X-ray powder diffraction
• Crystallization and preliminary X-ray diffraction experiments of arylmalonate decarboxylase from Alcaligenes bronchisepticus
• Low resolution models of self-assembled histone fibers from X-ray diffraction studies.