Papers by Keyword: ACAR

Abstract: Late Professor Stewart initiated and shaped the International Conference on Positron Annihilation (ICPA) series. As a first-generation experimental positron-annihilation scientist, he made full use of the angular correlation of annihilation radiation (ACAR) method. He applied this method to study Fermi surfaces of metals, positron wave-functions in crystals, positron-electron and -phonon many-body interactions, and the vacancy formation energy in solids. He also studied with this method positronium in liquids and solids (T. Hyodo, J. Phys. Conf. Series, 618 (2015) 012002). All these studies enjoyed by Professor Stewart will long be remembered by the positron study community.

Abstract: We report on an assessment of the position resolving Hamamatsu-R3292 series photo-multiplier tubes with respect to their use for Angular Correlation of Annihilation Radiation (2D-ACAR) spectroscopy. The PMTs were coupled with a segmented scintillator and mounted at the Munich 2D-ACAR spectrometer. A series of measurements were performed in order to determine the energy and position resolution as well as the efficiency of the setup. Although a position resolution of Δ_xFWHM=1.98 mm was achieved, further improvements are needed.