Focusing and Collimation of X Rays Using Microchannel Plates: An Experimental Investigation

Article type: Research Article

Authors: Chapman, H. N. | Nugent, K. A. | Wilkins, S. W. | Davis, T. J.

Affiliations: School of Physics, The University of Melbourne, Parkville, Victoria 3052, Australia | CSIRO, Division of Materials Science and Technology, Locked Bag 33, Clayton, Victoria 3168, Australia

Abstract: Focusing and collimation of 8 keV x rays has been demonstrated using microchannel plate (MCP) blanks with cylindrical channels. The focusing effect arises from total external reflection of x rays at the interior surfaces of the channels of a MCP and has been described previously by the authors. Point to point focusing was observed with flat and curved MCPs, and collimation from a point source to a quasi-parallel beam was observed with a curved MCP. Intensity profiles at the image plane and at other planes behind a flat MCP were obtained for a 20 × 40 μm2 x-ray source, and agree well with theoretical predictions. The flux in a 40-μm-diameter collector in the image plane was compared with the flux in the same plane, but without a MCP. The relative gain in flux increases linearly with the source to MCP distance, as predicted. A maximum relative gain in flux of 18 ± 1 was observed for a source to detector distance of 50 cm.

DOI: 10.3233/XST-1990-2203

Journal: Journal of X-Ray Science and Technology, vol. 2, no. 2, pp. 117-126, 1990