In-beam measurement of the position resolution of a highly segmented coaxial germanium detector

The position resolution of a highly segmented coaxial germanium detector was determined by analyzing the 2055 keV γ-ray transition of Zr90 excited in a fusion-evaporation reaction. The high velocity of the Zr90 nuclei imparted large Doppler shifts. Digital analysis of the detector signals recovered the energy and position of individual γ-ray interactions. The location of the first interaction in the crystal was used to correct the Doppler energy shift. Comparison of the measured energy resolution with simulations implied a position resolution (root mean square) of 2 mm in three-dimensions.