Analytical Applications of X-ray Excited Optical Fluorescence Spectra

Simulation of x-ray absorption near-edge spectra and x-ray fluorescence spectra of optically excited molecules.

The x-ray absorption near-edge spectra (XANES) and fluorescence spectra of molecules in the ground state and optically excited states are computed using time-dependent density functional theory and time-dependent Hartree-Fock theory. The calculated XANES spectra of optically excited methanol, benzonitrile, hydrogen sulphide, and titanium tetrachloride and the fluorescence spectra of optically e...

Forensic applications of X-ray fluorescence microscopy

The development of highly efficient X-ray optics has allowed the development of bench-top XRF systems which have high intensity X-ray beams with diameters ranging from 10 micrometres through to a few millimetres. Coupled with integrated high magnification optical cameras, these systems are ideally suited to the needs of the forensic scientist. A microscopic particle from a crime scene can be an...

X-Ray Fluorescence Microtomography in Biological Applications

Optical birefringence imaging of x-ray excited lithium tantalate

X-ray absorption in lithium tantalate induces large, long-lived (∼10 5 s) optical birefringence, visualized via scanning optical polarimetry. Similar birefringence measured from glass, sapphire, and quartz was two orders of magnitude weaker; much of this reduction can be accounted for by their smaller cross section for x-ray absorption. While x-ray induced charges can perturb local refractive i...

Optical imaging in tissue with X-ray excited luminescent sensors.

We report a high-spatial resolution imaging technique to measure optical absorption and detect chemical and physical changes on surfaces embedded in thick tissue. Developing sensors to measure chemical concentrations on implanted surfaces through tissue is an important challenge for analytical chemistry and biomedical imaging. Tissue scattering dramatically reduces the resolution of optical ima...