Developing Ge-Strip Detectors for Superheavy Physics

In-beam and decay spectroscopy of superheavy elements has significantly enhanced our understanding of the microscopic causes of their stability. Nuclei with high atomic (Z) and mass (A) numbers have closely spaced excited levels that decay via low energy γ-rays and internal conversion processes, producing X-rays. Segmented planar germanium detectors are well-suited for detecting low energy photons (25-500 keV). At UMass Lowell, we have been investigating the applications of a Germanium Double Sided Strip Detector (GeDSSD) for X-ray and low energy γ-ray spectroscopy in superheavy element research. Their pixelation allows them to be used both as a multi-detector device for measuring X-ray multiplicities as well as withstand higher count rates compared to standard HPGe detectors. They also provide the ability to measure linear polarization of low-energy transitions from their Compton scatters into adjacent horizontal and vertical pixels. A test experiment was performed at ANL using the ²⁰⁸Pb (⁴⁸Ca, 2n) ²⁵⁴No reaction that populates isomers that decay via cascades of low-energy transitions. A 3x3 cm² x 2 cm thick, 36-pixel GeDSSD was installed at the focal plane of AGFA and integrated into the X-Array spectrometer. Preliminary results of this test experiment as well as data from radioactive source measurements will be presented and discussed.