title: A prototype chopper for synchrotron time-resolved crystallographic measurements.
abstract: A mechanical x-ray chopper has been designed to perform microsecond time-resolved crystallographic studies at the DIAMOND synchrotron I19 beamline. It consists of two asymmetric absorbers rotating synchronously at frequencies from 0 to 50 Hz in the same direction around a rotation axis that is parallel to the x-ray beam. The duration of the x-ray pulses produced by the chopper is determined by the relative phase between the two blades, which can be adjusted. The chopper system presented in this paper offers a time resolution suitable for conducting in situ experiments that afford the crystal structure of materials while in their transient (>10 micros) photoactivated excited states.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
authors.forename: S L G
authors.initials: SL
authors.lastname: Husheer
authors.forename: J M
authors.initials: JM
authors.lastname: Cole
authors.forename: T
authors.initials: T
authors.lastname: d'Almeida
authors.forename: S J
authors.initials: SJ
authors.lastname: Teat