High resolution x-ray microscope

Abstract

The authors present x-ray images of grid meshes and biological material obtained using a microspot x-ray tube with a multilayer optic and a 92-element parabolic compound refractive lens (CRL) made of a plastic containing only hydrogen and carbon. Images obtained using this apparatus are compared with those using an area source with a spherical lens and a spherical lens with multilayer condenser. The authors found the best image quality using the multilayer condenser with a parabolic lens, compared to images with a spherical lens and without the multilayer optics. The resolution was measured using a 155-element parabolic CRL and a multilayer condenser with the microspot tube. The experiment demonstrates about 1.1μm resolution.

Nano-printed miniature compound refractive lens for desktop hard x-ray microscopy

“…Therefore, over the tube voltage range of 25 kV to 85 kV, the system resolution may vary, and contributes to the energy dependence of the size of the focal spot image as plotted in Fig 7 . If the polymer CRL is coupled to a quasi-monochromatic source, for example the characteristic line emissions of metal-anode x-ray tubes used in prior CRL studies [ 2 ][ 15 ], it can reasonably be expected to provide sub-micrometer resolutions.…”

“…This notion is supported by the observation of the same background level regardless of the changing focusing conditions with the sample-to-lens distance ( Fig 6 ). In prior imaging study with macro CRLs, the aperture condition was met by light-absorbing walls around the diameter of the CRL [ 2 ].…”

“…The field of view (FOV) of the polymer CRL is determined by the acceptance angle of the string of lenses in the CRL, rather than the diameter of each lens: the acceptance angle is the angle spanned by the radius of the front lens relative to the iso-center of the CRL [ 2 ]. From any point within this acceptance angle, the majority of light that enters the front lens of the CRL will also pass through the entire string of lenses and experience the full focusing effect.…”

“…Focusing elements for x-ray microscopy up to 10 keV photon energy include Kirkpatrick-Baez mirrors in benchtop microscopy [ 1 ], zone plates at 8 keV [ 2 ] and compound refractive lenses (CRL) which consist of linear arrays of individual refractive lenses [ 3 ]. The first CRLs were lines of cylindrical holes drilled into aluminum blocks [ 3 ], where the small refractions of individual holes were compounded to achieve a substantial focusing effect [ 3 ].…”

Focusing synchrotron radiation using a polycapillary half-focusing X-ray lens for imaging

“…For example, the X-ray image may first be converted into a visiblelight image using a scintillating crystal screen, and then this visiblelight image is recorded at a high spatial resolution using a visible-light detection system. As another example, the X-ray image may first be magnified using focusing X-ray optics (Mokso et al, 2007;Piestrup et al, 2005;Gary et al, 2007;Ollinger et al, 2007), and then this magnified image is recorded using an X-ray detection system with a relatively low spatial resolution. There are many focusing X-ray optics which can be used to focus a quasi-parallel synchrotron radiation beam into a spot with high flux density for magnifying the X-ray image, such as a zone plates, refractive X-ray lenses, Kirkpatrick-Baez mirrors, polycapillary X-ray optics, namely the Kumakhov lens (Dabagov et al, 1995), and others.…”