This disclosure relates to an apparatus and methods for applying X-ray reflectometry (XRR) in characterizing three dimensional nanostructures supported on a flat substrate with a miniscule sampling area and a thickness in nanometers. In particular, this disclosure is targeted for addressing the difficulties encountered when XRR is applied to samples with intricate nanostructures along all three directions, e.g. arrays of nanostructured poles or shafts. Convergent X-ray with long wavelength, greater than that from a copper anode of 0.154 nm and less than twice of the characteristic dimensions along the film thickness direction, is preferably used with appropriate collimations on both incident and detection arms to enable the XRR for measurements of samples with limited sample area and scattering volumes. In one embodiment, the incident angle of the long-wavelength focused X-ray is ≥24°, and the sample area is ≤25 μm×25 μm.

A method for X-ray scatterometry includes receiving a first distribution of an X-ray beam scattered from a sample. The first distribution exhibits asymmetry with respect to a reference axis. A correction is applied to the first distribution, so as to produce a second distribution in which a level of the asymmetry is reduced relative to the first distribution. One or more parameters of the sample are estimated based on the second distribution.

Crystallographic information of crystalline sample can be determined from one or more three-dimensional diffraction pattern datasets generated based on diffraction patterns collected from multiple crystals. The crystals for diffraction pattern acquisition may be selected based on a sample image. At a location of each selected crystal, multiple diffraction patterns of the crystal are acquired at different angles of incidence by tilting the electron beam, wherein the sample is not rotated while the electron beam is directed at the selected crystal.

Methods for quantitatively separating x-ray images of a subject having three or more component materials into component images using spectral imaging or multiple-energy imaging with 2D radiographic hardware implemented with scatter removal methods. The multiple-energy system may be extended by implementing DRC multiple energy decomposition and K-edge subtraction imaging methods.

Scatter correction for tomography: for each position, two images are acquired, a first image without and a second image with a scatter reducing aperture plate (50). A scatter image is calculated by subtracting the second image from the first image. The apertures (48) in the scatter reducing plate (50) are arranged hexagonally in order to optimise the packaging density of the apertures.

Disclosed is a method for identifying the molecular configuration of ganoderic acid A which comprises extracting ganoderic acid A from fruit bodies of Ganoderma lucidum, producing crystals of the ganoderic acid A, analyzing the crystals of the ganoderic acid A by X-ray structural analysis to obtain values of the three-dimensional coordinate of the crystals of the ganoderic acid A and using the values of the three-dimensional coordinate of the crystals of the ganoderic acid A obtained from the X-ray structural analysis as initial coordinates in the input to the calculation program of the B3LYP method included in the Gaussian 03 package software together with the 6-31G* basis set function of the density functional theory (DFT).

This disclosure relates to an apparatus and methods for applying X-ray reflectometry (XRR) in characterizing three dimensional nanostructures supported on a flat substrate with a miniscule sampling area and a thickness in nanometers. In particular, this disclosure is targeted for addressing the difficulties encountered when XRR is applied to samples with intricate nanostructures along all three directions, e.g. arrays of nanostructured poles or shafts. Convergent X-ray with long wavelength, greater than that from a copper anode of 0.154 nm and less than twice of the characteristic dimensions along the film thickness direction, is preferably used with appropriate collimations on both incident and detection arms to enable the XRR for measurements of samples with limited sample area and scattering volumes.

Methods for quantitatively separating x-ray images of a subject having three or more component materials into component images using spectral imaging or multiple-energy imaging with 2D radiographic hardware implemented with scatter removal methods. The multiple-energy system may be extended by implementing DRC multiple energy decomposition and K-edge subtraction imaging methods.

Various aspects include methods compensating for Compton scattering effects in pixel radiation detectors. Various aspects may include determining whether gamma ray detection events occurred in two or more detector pixels within an event frame, determining whether the detection events occurred in detector pixels within a threshold distance of each other in response to determining that detection events occurred in two or more detector pixels within the event frame, and recording the two or more detection events as a single detection event having an energy equal to the sum of the measured energies of the two or more detection events located in the detector pixel having a highest measured energy in response to determining that the detection events occurred in detector pixels within the threshold distance of each other.

This disclosure relates to an apparatus and methods for applying X-ray reflectometry (XRR) in characterizing three dimensional nanostructures supported on a flat substrate with a miniscule sampling area and a thickness in nanometers. In particular, this disclosure is targeted for addressing the difficulties encountered when XRR is applied to samples with intricate nanostructures along all three directions, e.g. arrays of nanostructured poles or shafts. Convergent X-ray with long wavelength, greater than that from a copper anode of 0.154 nm and less than twice of the characteristic dimensions along the film thickness direction, is preferably used with appropriate collimations on both incident and detection arms to enable the XRR for measurements of samples with limited sample area and scattering volumes. In one embodiment, the incident angle of the long-wavelength focused X-ray is 24, and the sample area is 25 m25 m.