Related papers: Johann-type laboratory-scale X-ray absorption spec…
Time-dependent and constituent-specific spectral changes in soft near edge X-ray spectroscopy (XAS) of an [Fe/MgO]$_8$ metal/insulator heterostructure upon laser excitation are analyzed at the O K-edge with picosecond time resolution. The…
We present photoionization models accounting for both photoelectric and resonant absorption. We demonstrate that resonance absorption lines are detectable even in moderate resolution X-ray spectra of type 1 AGN. The spectra transmitted by…
We present the design, fabrication, and commissioning of a new liquid cell for X-ray absorption spectroscopy, that allows measurement in both transmission and fluorescence modes. The design consists of easily demountable and replaceable…
When a laser-cooled atomic sample is optically excited, the envelope of coherent forward scattering can often be decomposed into a few complex Gaussian profiles. The convenience of Gaussian propagation helps addressing key challenges in…
Continued improvement of the energy resolution of resonant inelastic x-ray scattering (RIXS) spectrometers is crucial for fulfilling the potential of this technique in the study of electron dynamics in materials of fundamental and…
A number of emission and absorption features are expected to be visible in high energy resolution X-ray spectra of type 1 AGN with ionized gas along the line of sight (so called "warm absorbers"). Emission strongly depends on the…
X-ray diffraction with high spatial resolution is commonly used to characterize (poly-)crystalline samples with, for example, respect to local strain, residual stress, grain boundaries and texture. However, the investigation of highly…
The performance of hybrid GaAs pixel detectors as X-ray imaging sensors were investigated at room temperature. These hybrids consist of 300 mu-m thick GaAs pixel detectors, flip-chip bonded to a CMOS Single Photon Counting Chip (PCC). This…
Transient X-ray absorption techniques can measure ultrafast dynamics of the elemental edges in a material or multiple layer junction, giving them immense potential for deconvoluting concurrent processes. However, the interpretation of the…
To investigate the x-ray absorption (XAS) branching ratio from the core 4d to valence 5f states, we set up a theoretical framework by using a combination of density functional theory in the local density approximation and Dynamical Mean…
X-ray absorption spectroscopy is a premier element-specific technique for materials characterization. Specifically, the x-ray absorption near-edge structure (XANES) encodes important information about the local chemical environment of an…
We have built a vacuum double crystal spectrometer, which coupled to an electron-cyclotron resonance ion source, allows to measure low-energy x-ray transitions in highly-charged ions with accuracies of the order of a few parts per million.…
Electrolyte-based transistors utilizing ionic liquids/gels have been highly successful in the study of charge-density-controlled phenomena, particularly in oxides. Experimental probes beyond transport have played a significant role, despite…
We present a method for the measurement of small optical absorption coefficients. The method exploits the deformation of cavity Airy peaks that occur if the cavity contains an absorbing material with a non-zero thermo-refractive coefficient…
We present the design of a continuous-wave, highly sensitive optical spectrometer for millimeter-wave frequencies between 50 and 1000 GHz. The spectrometer uses photomixing of near-infrared light to generate radiation in a wide frequency…
I report on a sample of new type I X-ray bursters, firstly detected with the Wide Field Cameras on board BeppoSAX and then studied with the Narrow Field Instruments on a broad spectral range (0.1-200 keV). Properties of the…
We present a spectroscopic study of 41 hard X-ray sources detected serendipitously with high significance (> 5 sigma in the 2-10 keV band) in seven EPIC performance/verification phase observations. The large collecting area of EPIC allows…
We present a new technique called "quantile analysis" to classify spectral properties of X-ray sources with limited statistics. The quantile analysis is superior to the conventional approaches such as X-ray hardness ratio or X-ray color…
We discuss the broad band X-ray properties of one of the largest samples of X-ray selected type-1 AGN to date (487 objects in total), drawn from the XMM-Newton Wide Angle Survey. The objects cover 2-10 keV luminosities from ~10^{42}-10^{45}…
We report results of two BeppoSAX observations of the transient X-ray source XTE J0421+560 during the outburst that started in March 1998. The source exhibits radio jets and coincides with the binary system CI Cam. The 0.1--50 keV spectrum…