Development of a multi-lane X-ray mirror providing variable beam sizes.

D Laundy,I Nistea,G Evans,J Sutter,L Alianelli,I Pape,K Sawhney,S G Alcock

doi:10.1063/1.4950732

Abstract

Grazing incidence mirrors are used on most X-ray synchrotron beamlines to focus, collimate or suppress harmonics. Increasingly beamline users are demanding variable beam shapes and sizes at the sample position. We have now developed a new concept to rapidly vary the beam size and shape of a focused X-ray beam. The surface of an elliptically figured mirror is divided into a number of laterally separated lanes, each of which is given an additional longitudinal height profile calculated to shape the X-ray beam to a top-hat profile in the focal plane. We have now fabricated two prototype mirrors and present the results of metrology tests and measurements made with one of the mirrors focusing the X-rays on a synchrotron beamline. We envisage that such mirrors could be widely applied to rapid beam-size switching on many synchrotron beamlines.

Highlights

With low emittance synchrotron radiation sources, focused beam sizes below one micrometer full width at half maximum are routinely achieved using high quality focusing mirror optics
While beam size may be increased by changing the mirror curvature to produce an out of focus beam, such as by using a bimorph mirror, the resulting beam profile shows strong striations1,2 caused by surface errors on the optics
The measurements show that the profiling of mirror surfaces can be used to achieve a variable beam size

Summary

Introduction

With low emittance synchrotron radiation sources, focused beam sizes below one micrometer full width at half maximum (fwhm) are routinely achieved using high quality focusing mirror optics. The surface of an elliptically figured mirror is divided into a number of laterally separated lanes, each of which is given an additional longitudinal height profile calculated to shape the X-ray beam to a top-hat profile in the focal plane.

Results

Conclusion