I present a tractable theory for the resonant inelastic x-ray scattering (RIXS) of magnons. The low-energy transition operator is written as a product of local spin operators and fundamental x-ray absorption spectral functions. This leads to simple selection rules. The scattering cross section linear (quadratic) in spin operators is proportional to the fundamental magnetic circular (linear) dic...

The scattering of visible light by hexagonal-shaped column containing densely packed inclusions is simulated by a combination of ray-tracing and Monte Carlo techniques. While the ray tracing program takes care of the individual reflection and refraction events at the outer boundary of the particle, the Monte Carlo routine simulates internal scattering processes. A dense-medium light-scattering ...

Non-resonant inelastic x-ray scattering can provide information on various atomic-scale properties and phenomena by probing the spectrum of electronic excitations. The technique allows bulk-sensitive measurements and relatively freely tunable sample conditions even for excitations with energies in the soft x-ray range. Also non-dipolar excitations are accessible by virtue of the ability to impo...

1 Abstract This paper describes some recent work to extend the capability of the Epsilon™ Radar Cross Section (RCS) prediction code to model the scattering from diffusive and grating structures. The paper provides an overview of basic approaches to the calculation of multiple scattering interactions and then describes the Diffuse ray and Huygens algorithm extensions. A basic Shooting Bouncing R...

We investigate the hydrodynamic interaction in suspensions of charged colloidal silica spheres. The volume fraction as well as the range of the electrostatic repulsion between the spheres is varied. Using a combination of dynamic x-ray scattering, cross-correlated dynamic light scattering, and small angle x-ray scattering, the hydrodynamic function H(q) is determined experimentally. The effecti...

Dark-field images are formed by small-angle scattering of x-ray photons. The small-angle scattering signal is particularly sensitive to structural variations and density fluctuation on a length scale of several ten to hundred nanometers, offering a new contrast mechanism to reveal subtle structural variation of object. In this paper, we derive a novel physical model to describe x-ray absorption...

The afterglows of gamma-ray bursts (GRBs) have commonly been assumed to be due to shocks sweeping up the circum-stellar medium. However, most GRBs have been found in dense star-forming regions where a significant fraction of the prompt X-ray emission can be scattered by dust grains. Here we revisit the behavior of dust scattering of X-rays in GRBs. We find that the features of some X-ray afterg...

samples are also often weak x-ray scatterers, due to the low electron density contrast. X-ray measurements on these samples therefore require high x-ray intensity as well as low x-ray divergence. Taking advantage of the NSLS-II source brightness, the LIX beamline will provide capabilities for transmission and grazing incidence x-ray scattering with tunable beam size and divergence, to support s...

This paper derives the analytical expression of the temporal autocorrelation function (ACF) of the non-stationary three dimensional (3D) multipath scattering channels, in which scatterers move with constant velocities in random directions around transceivers. The analytical expression involves high dimensional integration within finite interval, thus a methodology based on ray-tracing is propos...

Ultrashort X-ray pulses from free-electron laser X-ray sources make it feasible to conduct small- and wide-angle scattering experiments on biomolecular samples in solution at sub-picosecond timescales. During these so-called fluctuation scattering experiments, the absence of rotational averaging, typically induced by Brownian motion in classic solution-scattering experiments, increases the info...