相关论文: Development of a compact HAPG crystal Von Hamos X-…
A next-generation medium-energy gamma-ray telescope targeting the MeV range would address open questions in astrophysics regarding how extreme conditions accelerate cosmic-ray particles, produce relativistic jet outflows, and more. One…
M\"ossbauer nuclei feature exceptionally narrow resonances at hard x-ray energies, which render them ideal probes for structure and dynamics in condensed-matter systems, and a promising platform for x-ray quantum optics and fundamental…
The application of a high purity germanium (HPGe) gamma spectrometer in determining the fuel element burnup in a future reactor is studied. The HPGe detector is exposed by a Co60 source with varying irradiation rate from 10 kcps to 150 kcps…
Extreme ultraviolet (XUV) lasers are essential for the investigation of fundamental physics. Especially high repetition rate, high photon flux sources are of major interest for reducing acquisition times and improving signal to noise ratios…
We have developed an experimental system to simultaneously observe surface structure, morphology, composition, chemical state, and chemical activity for samples in gas phase environments. This is accomplished by simultaneously measuring…
For x-ray spot sizes of a few tens of microns or smaller, a mm-sized flat analyzer crystal placed ~ 1 cm from the sample will exhibit high energy resolution while subtending a collection solid angle comparable to that of a typical…
One of the problems often encountered in X-ray mirror manufacturing is setting proper manufacturing tolerances to guarantee an angular resolution - often expressed in terms of Point Spread Function (PSF) - as needed by the specific science…
We demonstrate near-atomic-resolution Bragg diffraction from aerosolized single granulovirus crystals using an x-ray free-electron laser. The form of the aerosol injector is nearly identical to conventional liquid-microjet nozzles, but the…
We have observed Bragg scattering of photons from quantum degenerate $^{87}$Rb atoms in a three-dimensional optical lattice. Bragg scattered light directly probes the microscopic crystal structure and atomic wavefunction whose position and…
Extreme ultraviolet pulses as generated by high harmonic generation (HHG) are a powerful tool for both time-resolved spectroscopy and coherent diffractive imaging. However, the integration of spectroscopy and microscopy to harness the…
The hard X-ray emission from magnetars and other isolated neutron stars remains under-explored. An instrument with higher sensitivity to hard X-rays is critical to understanding the physics of neutron star magnetospheres and also the…
X-ray spectra of active galactic nuclei (AGN) consist of several different emission and absorption components, which are often fitted manually with models chosen on a case-by-case basis. However, it becomes very hard for a survey with a…
Light sources based on high-harmonic generation (HHG) underpin ultrafast spectroscopy experiments across a large range of photon energies, spanning from the extreme-ultraviolet to the soft x-ray. To this day their design, implementation and…
Spectral functions measured with angle-resolved photoemission spectroscopy (ARPES) provide key insight to elucidate the band structure of materials. Comparison with theory requires computing dynamical one-point functions in some equilibrium…
Hyperspectroscopy is a new method of surface image taking, providing simultaneously high position and spectral resolutions which allow one to make some conclusions about chemical compositions of the surfaces. We are now studying…
Optical-domain Transient Grating (TG) spectroscopy is a versatile background-free four-wave-mixing technique used to probe vibrational, magnetic and electronic degrees of freedom in the time domain. The newly developed coherent X-ray Free…
The observed hard X-ray (HXR) flux spectrum $I(\epsilon)$ from solar flares is a combination of primary bremsstrahlung photons $I_P(\epsilon)$ with a spectrally modified component from photospheric Compton backscatter of downward primary…
``Oversimplified'' and ``simplified'' methods based on true coincidence summing effect used in uncomplicated determination of the photo-peak efficiency of the semiconductor High Purity Germanium (HPGe) detector system are suggested and…
Coherent X-ray photons with energies higher than 50 keV offer new possibilities for imaging nanoscale lattice distortions in bulk crystalline materials using Bragg peak phase retrieval methods. However, the compression of reciprocal space…
Optical spectrometers have propelled scientific and technological advancements in a wide range of fields. While sophisticated systems with excellent performance metrics are serving well in controlled laboratory environments, many…