Positron irradiation effects on polypropylene and polyethylene studied by positron annihilation

Positron Annihilation Spectroscopy

Positron annihilation spectroscopy is nowadays well recognised as a powerful tool of microstructure investigations of condensed matter. An overview of the method aimed for users from other fields is given and supplemented with several examples of applications.

Positron Annihilation on Atoms and Molecules

OF THE DISSERTATION Positron Annihilation on Atoms and Molecules

Effect of carbon on copper precipitation in deformed Fe-based alloys studied by positron annihilation spectroscopy

The role of deformation-induced defects and carbon addition on the copper precipitation during aging at 550 o C is investigated in high-purity Fe-Cu-B-N-C alloy samples by Coincidence Doppler Broadening. In samples with 0% and 8% cold pre-strain, the influence of tensile pre-deformation on the precipitation kinetics of copper is studied. The deformationinduced defects are found to enhance the C...

Mechanisms of positron annihilation on molecules

The aim of this work is to identify the mechanisms responsible for very large rates and other peculiarities observed in low-energy positron annihilation on molecules. The two mechanisms considered are: (i) Direct annihilation of the incoming positron with one of the molecular electrons. This mechanism dominates for atoms and small molecules. I show that its contribution to the annihilation rate...

Structure of dislocations in Al and Fe as studied by positron-annihilation spectroscopy.