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Design and manufacture of mini-beam collimators for macromolecular crystallography at the GM/CA-CAT at APS

Published online by Cambridge University Press:  01 November 2010

S. Xu*
Affiliation:
Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
V. Nagarajan
Affiliation:
Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
R. F. Fischetti
Affiliation:
Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
*
Email address for correspondence: sxu@anl.gov
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Abstract

Since 2007, we have offered single collimators for mini beams of sizes 5, 10 and 20 µm as well as a 300 µm scatter-guard to accommodate the fully focused beam. The advantages of varying the beam size were obvious, better signal/background ratio and the capability to raster with a coarse, larger beam, then fine tune with one of the mini-beam options. The mini beams proved to be a technical and popular success; however, the switching of the single collimators often involved staff intervention. The single mini-beam collimators were the precursors to the development of a triple collimator. This implementation incorporated two mini-beam collimators and a 300 µm scatter-guard on one post. The design was improved by consolidation of fabrication from a single piece of molybdenum block. It significantly improved the robustness, ease of initial alignment, reduction of background and increased automation. However, experimenters were still left with a choice of either a (5, 10 and 300 µm)- or a (10, 20 and 300 µm)-triple collimator. Recently, a quad collimator was developed and fabricated to provide a selection of mini beams of 5, 10 and 20 µm and a 300 µm scatter-guard, on a single post. We will present the mechanical design of multi-collimators, results of measured beam flux through the collimator pinholes.

Type
Contributed paper
Copyright
Copyright © Diamond Light Source Ltd 2010

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References

REFERENCES

Fischetti, R. F., Xu, S., Yoder, D., Becker, M., Nagarajan, V., Sanishvili, R., Hilgart, M. C., Stepanov, S. & Smith, J. L. 2009 Mini-beam collimator enables micro-crystallography experiments on standard beamlines. J. Synchrotron Radiat. 16, P217P225.CrossRefGoogle Scholar
Fischetti, R. F., Yoder, D. W., Xu, S., Stepanov, S., Makarov, O., Benn, R., Corcoran, S., Diete, W., Schwörer-Böhing, M., Signorato, R., Schröder, L., Berman, L., Viccaro, P. J. & Smith, J. L. 2007 Optical performance of the GM/CA CAT canted undulator beamlines for protein crystallography. In Synchrotron Radiation Instrumentation: Ninth International Conference (ed. Choi, J.-Y. & Rah, S.), pp. 754757. American Institute of Physics.Google Scholar
Sanishvili, R., Nagarajan, V., Yoder, D., Becker, M., Xu, S., Corcoran, S., Akey, D. L., Smith, J. L. & Fischetti, R. F. 2008 A 7 µm mini-beam improves diffraction data from small or imperfect crystals of macromolecules. Biol. Crystallogr. D64, Part 4, P425P435.CrossRefGoogle Scholar
Xu, S. & Fischetti, R. F. 2007 Design and performance of a compact collimator at GM/CA-CAT for macromolecular crystallography. In SPIE 2007, Proceedings of SPIE, Vol. 6665-66650X_ P1-8.Google Scholar
Xu, S., Fischetti, R. F., Benn, R. & Corcoran, S. 2007 Design and performance of the compact YAG imaging system for diagnostics at GM/CA beamlines at APS. In Synchrotron Radiation Instrumentation: Ninth International Conference (ed. Choi, J.-Y. & Rah, S.), pp. 14031406. American Institute of Physics.Google Scholar
Xu, S., Makarov, O., Benn, R., Yoder, D. W., Stepanov, S., Becker, M., Corcoran, S., Hilgart, M., Nagarajan, V., Ogata, C. M., Pothineni, S., Sanishvili, R., Smith, J. L. & Fischetti, R. F. 2010 Micro-Crystallography Developments at GM/CA-CAT at the APS. American Institute of Physics. Conference Proceedings 1234, pp. 897–900.CrossRefGoogle Scholar