We developed a single-shot coherent X-ray imaging instrument at the hard beamline of Pohang Accelerator Laboratory Free Electron Laser (PAL-XFEL). This experimental platform was established to conduct variety XFEL experiments, including diffraction (CDI), photon correlation spectroscopy (XPCS), and scattering (CXS). Based on forward-scattering geometry, this utilizes fixed-target method for sam...

In this work several structural and chemical properties of self-assembled InAs islands grown on GaAs(001) are studied using surface x-ray scattering with synchrotron radiation. The technique of x-ray diffraction under grazing incidence condition was employed to differentiate coherent and incoherent islands. We used a model of a strained pyramidal island to interpret the x-ray results and correl...

A novel method of producing intense short wavelength radiation from relativistic electrons is described. The electrons are periodically bunched at the wavelength of interest enabling in-phase superradiant emission that is far more intense than from unbunched electrons. The periodic bunching is achieved in steps beginning with an array of beamlets emitted from a nanoengineered field emission arr...

X-ray free-electron lasers (XFELs) generate sequences of ultra-short spatially coherent pulses of X-ray radiation. A diffraction focusing spectrometer (DFS), which is able to measure the whole energy spectrum of the radiation of a single XFEL pulse with an energy resolution of ΔE/E 2 × 10(-6), is proposed. This is much better than for most modern X-ray spectrometers. Such resolution allows one ...

We have developed a 3 dimensional Coherent Diffraction Imaging (CDI) algorithm to retrieve phases of diffraction patterns samples in Grazing Incidence Small Angle X-ray Scattering (GISAXS) experiments. The interprets the using Distorted-Wave Born Approximation (DWBA) instead (BA), as this case existence reflected beam from substrate causes pattern deviate significantly simple Fourier transform ...

We present a QCD calculation of the coherent multiple scattering effect on single hadron production in semi-inclusive lepton-nucleus deep inelastic scattering (DIS). We show that the destructive interference of coherent multiple scattering leads to suppression in hadron productions. The suppression is similar to the expectations of energy loss calculations. We compare our calculation with exper...

We give an estimate of the relative error in the angular measurement of observations for high redshift objects induced by gravitational scatterings (lensing). Gunn (1967) concluded that the gravitational scatterings by galaxies induce the relative error of a few percent in the observations for objects at z = 1. This estimate has been considered as a fundamental limitation of accuracy of the ang...

A microwave scattering formulation is presented for grassland and other short vegetation canopies. The fact that the constituent elements of these targets can be as large as the vegetation layer make this formulation problematic. For example, a grass element may extend from the soil surface to the top of the canopy, and thus the upper portion of the element can be illuminated with far greater e...

1 Introduction Coherent optical techniques contrast with those based on incoherent processes such as laser induced fluorescence or spontaneous Raman scattering by emitting a signal in a laser-like beam of radiation. For combustion diagnostics this presents obvious advantages for efficient collection of the signal and discrimination against background noise from scattered light or luminescence f...

The fundamental dichotomy between incoherent (phase independent) and coherent (phase dependent) light scattering provides the best criterion for a classification of biological structural color production mechanisms. Incoherent scattering includes Rayleigh, Tyndall, and Mie scattering. Coherent scattering encompasses interference, reinforcement, thin-film reflection, and diffraction. There are t...