Synchrotrons charge-coupled devices with

Except for in house preliminary studies, the intensities of X-rays diffracted by hydrogenase crystals are now usually obtained with synchrotron radiation (Fig. 6.2) and detected by image plate or charge coupled device (CCD) detectors. To limit the damage induced by the powerful photon flux of synchrotrons, the crystals are usually mounted in a small loop, flash cooled in either liquid propane or nitrogen and stored... 

The multiwire devices, though workhorses for about 10 years, were an intermediate in the development of the detectors we use today. They provided excellent data, but even faster, more reliable, more accurate devices became available in the late 1980s. The instruments that we use today fall into two categories those based on what are called image plates, and those based on charge coupled devices (CCD) detectors. While CCD detectors are now exclusively used at synchrotrons because of their almost instantaneous readout of data, necessary with high intensity sources with short exposure times, most university and private laboratories continue to use detectors based on image plates. 

Accurate experimental electronic properties can now be obtained in only one day with synchrotron radiation and a charge-coupled device area detection technique. Recently spectacular electron densities were acquired on DL-proline monohydrate at 100 K.130 The accuracy of the data is comparable or even superior to the accuracy obtained from a 6-week experiment on DL-aspartic acid with conventional X-ray diffraction methods. A data acquisition time of one day is comparable to the time needed for an ab initio calculation on isolated molecules. This technique renders larger molecular systems of biological importance accessible to electron density experiments. The impact of the rapid collection of accurate data should not be underestimated. Indeed, if properly allocated a dedicated synchrotron source could now routinely produce accurate experimental densities at a dramatically increased rate. 

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