Production of intense micrometer-sized x-ray beams with tapered glass monocapillaries

Abstract

Methods were developed to characterize tapered capillaries as x-ray concentrators capable of forming spots of intense x-ray radiation with micrometer diameters. These tapered capillaries, with somewhat controlled tapers, were produced using a gravity-based capillary puller. A device was constructed to microscopically inspect these capillaries along two orthogonal axes in order to accurately measure the tapering and bending. Both monochromatic and white hard x rays were concentrated with a variety of tapered capillaries, and the subsequent gains in intensity (flux/area) ranging from 14 to 35 are reported. Using these unique x-ray concentrators, a simple high-powered x-ray fluorescence microscope was constructed and tested. We also found that hard x-ray beams could be successfully steered by bending the capillary tip with radii as small as 5 m. In addition, preliminary ray-tracing results obtained from a two-dimensional ray-tracing program are described.

A microbeam collimator for high resolution x-ray diffraction investigations with conventional diffractometers

“…This is certainly a quite lower value than the 0.32°reported for glass monocapillaries. 7,8 Due to this low angular divergence, the present collimator can be placed at relatively larger distances from the sample surface, i.e., as far as 17 mm, without significant loss in spatial resolution ͑see Sec. III D͒, facilitating, therefore, the experimental handling.…”

“…[3][4][5][6] Most approaches for quasiparallel microbeam generation are based on the multiple total reflection of x rays inside lead glass monocapillaries. [1][2][3][4]7,8 Directing the source x rays toward the capillary tube entrance, the incident beam may be compressed, as long as the angle of incidence for each re-flection remains below the critical value c . For lead glass and x-ray photons of 8 keV, c does not exceed 3 mrad ͑0.17°͒.…”

High intensity monocapillary X-ray guide tube with 10 micrometer spatial resolution for analytical X-ray microscope

“…In this paper, the comparison among the commercially available polycapillary [1] and a monocapillary [2][3][4] X-ray guide tubes is studied to realize the ideal analytical X-ray microscope without the use of the synchrotron. With the lower energy source, an X-ray analytical microscope minimizes sample pre-treatment and provides sufficient spatial resolution.…”

Investigations of X-ray metallic capillaries

“…The first inventors and users of the capillaries were often fascinated with their multiple reflection abilities [24][25][26][27]. They probably expected that capillaries can be used as a very flexible waveguides deflecting the primary beam by a large angle.…”