Using HGe and LaBr detectors in gamma-gamma-coincidence applications.

In the past decade, nuclear detectors have been subject to increasing demands for accuracy and efficiency. High Purity Germanium (HPGe) detector arrays are an excellent example of a high precision detector born of this demand, as they boast an energy resolution of below 0.1% at 1 MeV. While the superior energy resolution of HPGe detectors is ideal for gamma-gamma coincidence analysis, the relatively poor timing resolution results in increased random coincidences and decreased SNR. Instead, Lanthanum Bromide (LaBr$_3$) scintillators have a much faster response (100 ps). They allow for precise time gating in gamma-gamma coincidence analysis, but can produce spectra with ill-defined peaks due to their low energy resolution. We use Geant4 and ROOT to investigate a combination of LaBr$_3$ and HPGe detectors in the measurement of fusion-evaporation reactions, resulting in an improved SNR when compared to spectra obtained by measuring with LaBr$_3$ or HPGe detectors on their own. This technique could provide a significant improvement to experiments using fast external triggers, and environments with strongly competing channels. We will demonstrate the application of this method for the range verification in ion beam radiation therapy, and in the identification of superheavy elements.