Dariusz Dziczek

Magnetic angle changer?a new device allowing extension of electron?photon coincidence measurements to arbitrarily large electron scattering angles

The electron–photon coincidence technique has been used as the most sensitive tool for investigating inelastic collisions of atoms with electrons and heavy particles and led to new insights into collision dynamics theory. However, for purely geometrical reasons, due to finite sizes of the electron energy analysers and electron beam sources, the measurements have not been carried out for the largest scattering angles. We present a novel system for electron–photon coincidence experiments on electron inelastic scattering with the magnetic angle changer allowing determination of excitation parameters at arbitrarily large scattering angles. As shown by experimental tests, our device can be successfully used in the electron–photon coincidence experiment and it has unprecedented efficacy—deflection angle up to 60° for 100 eV electrons, without a ferromagnetic core.

Coincidence measurements of electron-impact coherence parameters for e-He scattering in the full range of scattering angles

Electron impact coherence parameters for inelastic e-He scattering have been measured for the excitation to the 2 {sup 1}P{sub 1} state at collision energy of 100 eV. The experiment was conducted using angular correlation electron-photon coincidence technique with a magnetic angle changer allowing measurements in full range of scattering angles. The results are compared with other experimental data and theoretical predictions available for this collisional system.

Electron-photon coincidence measurements of polarization of radiation from cadmium atoms excited to 51P1 state by electron impact

The coherence analysis technique has been used to determine the state of polarizatitn of 228.8 nm radiation emitted by cadmium atoms excited to 51P1 state by electron impact. Data have been obtained for incident electron energy of 100 eV for scattering angles in the range from 10° to 40°. Reduced Stokes parameters and electron impact coherence parameters (EICP), characterizing the state of the excited atoms immediately after the collision, have been extracted from the measurements and compared with results of relativistic distorted-wave approximation calculations. Theoretical predictions are in good qualitative agreement with experimental values.

Electron-Photon Polarisation Correlation Experiment on Electron Impact Excitation of the First 4lPl State of Ca Atoms

Excitation processes of metal atoms are of great interest for astrophysics and plasma physics. Ca is for instance an element contributing many lines to spectra of solar - type stars and also the lines of other metal atoms are often used for diagnostic purposes l,2. Alkaline earth atoms are often seen as relatively simple multielectron systems since for most purposes they can be considered composed of two valence electrons outside an inert inner electron core.