Metal-coated capillary optics for soft x-ray

Abstract

A glass capillary with inner metal coating is proposed as a high efficiency, soft x-ray optic for medical applications. Based on results of theoretical calculation, for x-ray radiated from conventional x-ray tube, nickel is chosen as a coating material. A nickel-coated capillary is fabricated by using electroless deposition and the focusing and collimating effects are observed from measurement of transmission efficiency of soft x-ray.

Characterization and application in XRF of HfO2-coated glass monocapillary based on atomic layer deposition*

“…Monocapillary, a single hollow tube, is a popular device for x-ray focusing and collimation. [1,2] It usually presents a cylindrical, conically tapered, paraboloidal or elliptical shape [3][4][5] and is mainly used to obtain a small x-ray beam for experiments such as micro-x-ray fluorescence (micro-XRF) instrument [6,7] and x-ray nano-imaging system. [8,9] In monocapillary, only the portion of x-rays with incident angles less than the critical angle can be totally reflected on the inner wall of the tube and transmitted through the hollow core region.…”

“…That is to coat a highdensity film in the inside of capillary and many researchers have tried this method. In 2005 Matsuura et al [2,16] fabricated nickel-coated monocapillaries by a plating method. In order to achieve better adhesion of the nickel layer onto the glass, the surface of the silica was sensitized with ammonium fluoride solution, which resulted in some clusters of nickel on the surface.…”

“…And monocapillary with length ∼10 cm is commonly used. [2,16,17] The HfO 2 film is selected considering the fact that its density is higher than that of glass and it is chemically stable with melting temperatures as high as 2758 • C.…”