Speaker
Description
Depth resolved positron annihilation Doppler-broadening spectroscopy (DBS) at
the top-most atomic layer of solid materials is a fundamental but largely
unexplored field of research. This is because it requires monoenergetic
positron beams with energies in the order of only a few of eV.
SLOPE (Setup for LOw-energy Positron Experiments) is specially designed for
a low energy beam, enabling measurements down to implantation energies of
around 1 eV.
Previous depth resolved DBS measurements at SLOPE revealed a significant increase
in three gamma events at implantation energies below around 10 eV. This effect
is related to the Ore gap, which is the energy between the threshold of
Ps formation and the ionization energy of the target material.
We will present experimental results of this effect which showcase the
state-of-the-art capabilities of SLOPE.
