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Improvements in real-time data acquisition for gas electron diffraction

1986; American Institute of Physics; Volume: 57; Issue: 5 Linguagem: Inglês

10.1063/1.1138646

1527-2400

John D. Ewbank, Lothar Schäfer, David W. Paul, David L. Monts, W. L. Faust,

Spectroscopy and Laser Applications

Several improvements are described of a recently reported prototype real-time data-acquisition system for gas electron diffraction (GED), in which the scattered intensity distribution is recorded by a photodiode array. The use of a computer-designed and photographically produced ‘‘butterfly’’ slit in the optical track of the instrument, which simulates the effects of the rotating sector of conventional GED, as well as a number of other modifications, now makes it possible to record, for the first time by this technique, scattered electron intensities in a region around s=300 nm−1. Modeling of several test molecules shows that structural parameters can be determined accurately by the novel procedure, but systematic inaccuracies still exist in the determination of mean amplitudes of vibration. Data evaluation is based on a novel ratiometric analysis procedure, whose essential features are briefly discussed.