Biomedical subjects

Stephen D Kevan

Publications and source records attributed to Stephen D Kevan.

2 recordsLinked to original sources

PubMed2006

Speckle patterns with atomic and molecular de Broglie waves.

We have developed a nozzle source that delivers a continuous beam of atomic helium or molecular hydrogen having a high degree of transverse coherence and with adequate optical brightness to enable new kinds of experiments. Using this source we have measured single slit diffraction patterns and the first ever speckle-diffraction patterns using atomic and molecular de Broglie waves. Our results suggest fruitful application of coherent matter beams in dynamic scattering and diffractive imaging at short wavelength and with extreme surface sensitivity.

Journal Article↗

PubMed2003

Quasistatic x-ray speckle metrology of microscopic magnetic return-point memory.

We have used coherent, resonant, x-ray magnetic speckle patterns to measure the statistical evolution of the microscopic magnetic domains in perpendicular magnetic films as a function of the applied magnetic field. Our work constitutes the first direct, ensemble-averaged study of microscopic magnetic return-point memory, and demonstrates the profound impact of interfacial roughness on this phenomenon. At low fields, the microscopic magnetic domains forget their past history with an exponential field dependence.

Journal Article↗