Feasibility of X-ray beam nanofocusing with compound refractive lenses

A more general analytical theory of X-ray beam propagation through compound refractive lenses (CRLs) than the earlier study by Kohn [(2003). JETP, 97, 204–215] is presented. The problem of nanofocusing with CRLs is examined in detail. For a CRL with a relatively large aperture the focusing efficiency is limited by the radiation absorption in the lens material. The aperture does not affect the focusing process and it is replaced by the effective aperture. The X-ray transverse beam size at the focus is then by a factor of γ = β/δ times smaller than the transverse beam size just behind the CRL. Here, δ and β are the real and imaginary parts of the CRL material refractive index n = 1 − δ + iβ. In this instance, to improve focusing efficiency, it is advantageous to decrease the CRL aperture and increase the photon energy E. However, with increasing photon energy, the material absorption decreases, which results in the CRL aperture impact on the transverse beam size. The latter leads to the fact that with a proper CRL length the beam size is independent of both the aperture and photon energy but depends only on the CRL material electron density and is approximately equal to w c = λ/(8δ)1/2, where λ denotes the radiation wavelength, as predicted by Bergemann et al. [(2003). Phys. Rev. Lett, 91, 204801].

MoS2monolayers on Si and SiO2nanocone arrays: influences of 3D dielectric material refractive index on 2D MoS2optical absorption

The weak light confinement in low refractive index SiO2nanocone (NC) leads to greater optical absorption in the MoS2monolayers on SiO2NCs, compared with that on Si NCs.

The Study of Polymer Material Transference Phenomenon Measurement Method

In this paper, for the transference phenomenon of high polymers, a method of measurement system based on sodium light and feisuo interference with digital image processing technology was proposed. At first, the system measurement scheme and method were explained and there were some experiments with micro moleculesIn the experiment, the high polymer is the mixture of acetone and organic glass by a certain ratio, the micro molecules are Acetone and ethanol; at last, the interference strips were collected at interval time by using the image control collection procedure and processed. After thinning the fringes, we calculated the fringe spacing distance by K-L transform, by measuring the fringe spacing change in the polymer transference of acetone and ethanol we draw the change rule of the Polymer material refractive index :in 10 mins, the fringe spacing became to 40 percent , the refractive index became 2.5 times and keep invariant for Polymer material; in 50 mins, the fringe spacing became to 56 percent ,the refractive index became 1.7 times and kept invariant for ethanol. That’s all, at the time of balance, it will not infect the capability of the Polymer material any longer.

The Effect of Metal Impregnation on the Microstructure of Porous Vycor Glass

It has recently been demonstrated that highly resolved images can be produced by photochemical deposition of metal oxides in porous Vycor glass. This process has potential applications to the development of integrated optics in glass since it enables one to deposit in the same material refractive index patterns of optically and electro-magnetically active adsorbates. In order to learn in more detail about the interaction of the metal oxides with the glass, we impregnated porous Vycor glass (PVC) with tin or iron oxides and analyzed the samples with electron microscopy, x-ray microprobe analysis, and small angle x-ray scattering (SAXS). The results indicate that even though both oxides produce images of comparable resolution (approx 1μ), the interaction with the glass surface and particulate distribution is different for the two oxides. In particular, the Sn oxide appears to chemically modify the glass surface and prevents its consolidation.