7 papers
3D evolution of protein networks and lipid globules in heat-treated egg yolk
Felix Wittwer, Nimmi Das Anthuparambil, Frederik Unger +5
Upon heating, egg yolk transforms from a liquid to a gel due to protein denaturation. This process can serve as a useful model to better understand protein denaturation in general.…
Multi-modal strain mapping of steel crack tips with micrometer spatial resolution
Ahmar Khaliq, Felix Wittwer, Markus Hartmann +6
Due to their superior fatigue strength, martensitic steels are the material of choice for high cyclic loading applications such as coil springs. However, crack propagation is influ…
X-ray Strain and Stress Tensor Tomography
Peter Modregger, James. A. D. Ball, Felix Wittwer +2
The microscopic distribution of strain and stress plays a crucial role for the performance, safety, and lifetime of components in aeronautics, automotive and critical infrastructur…
Ultimate Sensitivity in X-ray Diffraction: Angular Moments vs. Shot Noise
Peter Modregger, Felix Wittwer, Ahmar Khaliq +6
The sensitivity of x-ray diffraction experiments towards Bragg peak parameters constitutes a crucial performance attribute of experimental setups. Frequently, diffraction peaks are…
Measurements of dislocations in 4H-SiC with rocking curve imaging
Ahmar Khaliq, Felix Wittwer, Niklas Pyrlik +9
4H Silicon Carbide (4H-SiC) combines many attractive properties such as a high carrier mobility, a wide bandgap, and a high thermal conductivity, making it an ideal candidate for h…
Annular x-ray optics offer superior resolution for radiation sensitive samples
Felix Wittwer, Peter Modregger
High-resolution x-ray microscopy requires a high photon flux to measure the signal from weakly scattering samples. This exposes samples to high radiation doses, potentially damagin…
Parallax in angular sensitive powder diffraction tomography
Peter Modregger, Ahmar Khaliq, Felix Wittwer
While a few methods for the determination of depth-resolved strain distributions each with inherent limitations are available, tomographic reconstruction has been applied to this p…