XAS measurements were performed at beamline E4 at the Hamburger Synchrotron Strahlungslabor (HASYLAB) under ambient conditions at 293 K. A Si(111) double crystal monochromator was used for measurements at the Cu K-edge (8.979 keV). The second monochromator crystal was tilted for optimal harmonic rejection. The energy resolution for the Cu K-edge energy is estimated to be 3.0 eV. The spectra wer...

Previous results for the shift of the ionisation potential of an atom in a laser field are used to investigate the kinematics of multiphoton ionisation in either a laser beam or a laser pulse. Previous results for a laser beam show essentially no shifts of the 'above-threshold ionisation' peaks in the electron energy distribution and only small widths. Results for a laser pulse show the possibi...

The aim of this work was to track and verify the delivery of respiratorygated irradiations, performed with three versions of TrueBeam linac, using a novel phantom arrangement that combined the OCTAVIUS® SRS 1000 array with a moving platform. The platform was programmed to generate sinusoidal motion of the array. This motion was tracked using the real-time position management (RPM) system and fo...

Experimental results on partial photo-ionisation cross sections of helium are analysed in the light of recent advances in the semiclassical theory of two-electron atoms. Byun et al [1] predict that the total photo-ionisation cross section below the double-ionisation threshold can, semiclassically, be described in terms of contributions associated with classical orbits starting and ending in the...