Upgrading the UKAL DAQ for Improved γ-ray Spectroscopy*

A new CAEN-based digital data acquisition system (DAQ) and high-purity germanium detector (HPGe) were installed at the University of Kentucky Van de Graaff Accelerator Laboratory (UKAL). The first step in implementing the new system was to adjust the trapezoidal filter parameters to try to optimize the detector resolution and system counts rates using radioactive sources, such as 60Co. Once these items were satisfactory, the new DAQ was further tested by performing measurements of the γ-ray angular distributions following inelastic neutron scattering from 136Xe. Measurements were obtained using a solid 136XeF2 sample. Spectra were taken for five angles with respect to the incident beam direction, ranging from 40° to 150°. These measurements were then analyzed to yield multipole mixing ratios (δ) of specific γ-ray transitions. The resulting values were compared with data previously taken using the older analog DAQ. It was found that the mixing ratios obtained were in agreement with the previous values within uncertainties. Optimization of the digital DAQ for improved resolution and dead time is ongoing.