New generation of polycapillary lenses: manufacture and applications

Abstract

A polycapillary x-ray lens is an effective element for radiation control. However, owing to the influence of several factors (efficiency of radiation capture by the capillary, absorption of radiation during its propagation through the capillary, etc.), a photon energy exists at which the lens has a maximum efficiency. The value of this energy is mainly determined by the diameter of the individual capillaries. In this paper, a new generation of polycapillary lenses with a combined structure is proposed. The developed lens consists of structures with different channel sizes and glass types. Capillary channels with larger sizes transport radiation of lower energies more effectively and capillary channels with smaller sizes transport radiation of higher energies more effectively. A comparison of the characteristic parameters of conventional lenses with a homogeneous structure and of new lenses with a combined structure was carried out. Examples of applications of these new lenses are given.

Examples of XRF and PIXE imaging with few microns resolution using SLcam® a color X‐ray camera

“…However, to acquire a spatially resolved image of a divergent X-ray source -which is the case for XRF and PIXE -an X-ray optics needs to be used to guide photons from small regions on a sample to corresponding pixels on the detector. In this respect, polycapillary optics [13] works as a bunch of independent X-ray channels gathering the photons from the X-ray source and bringing them to a proper section of the charge-coupled device. The polycapillary optics is a bundle of glass tubes with a typical diameter of several microns separated by a thin wall.…”

Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

“…These are (1) grazing-incidence x-ray mirrors or mosaic Bragg crystals to deflect the x-ray beam and remove the detector from the path of the streaming neutrons 168 ; (2) bundles of glass capillaries [168][169][170][171] to increase the effective solid angle of the x-ray source, while partially shielding the nuclear radiation; (3) alternate detector materials or detector types with reduced response to neutrons and gamma rays and/or with higher radiation-damage thresholds 172 ; (4) optimization of neutron/gamma-ray collimation and shielding of the detectors; and (5) active rejection or background subtraction of detector events resulting from impinging neutrons or gamma rays. Each of these techniques can reduce, but not eliminate, the background-noise and/or detector-damage problems.…”

X-ray diffraction imaging of bulk polycrystalline materials

“…Further treatment of such structures leads to so-called polycapillary lenses which are used for controlling X-radiation (focusing, parallelizing, filtering, etc.) [7,8].…”