MacCHESS has implemented five CCD-based x-ray detectors; a Princeton 1k detector, the Princeton Scientific Instruments 2k detector, an Area Detector Systems Corporation (ADSC) 1k detector and two ADSC Quantum 4 mosaic detectors. As part of the process of testing and calibrating these detectors we routinely measure data using the various CCD detector systems. During the past year the two Quantum 4 detectors were installed and debugged and are now routinely available for routine data collection. As part of the installation, a detector mount was developed that provide for a two-theta offset. During the past year we have developed a local calibration system based on a portable x-ray generator. In addition, we found that the DENZO data processing package did not support the Quantum 4 detector and established a collaboration to develop a separate software package using MOSFLM as the integration program. All of these developments have reached a stage where users can routinely collect and process data. All of these developments were first tested using crystals for which we have a great deal of experience. These include bovine purine nucleoside phosphorylase (cubic) and E.coli purine nucleoside phosphorylase (hexagonal) which we routinely use for testing detector performance. Both crystals are reproducible, diffract to high resolution, freeze well and have high symmetry. Therefore, they provide excellent test samples for detector testing. In the future we will test a 2k CCD module from ADSC that will serve as the basis of a 2k version of the Quantum 4. This detector will have an active area of 20 cm x 20 cm and 16 million pixels.
Showing the most recent 10 out of 375 publications
