The Electron-Gamma Coincidence Setup DAGOBERT

B. Hesbacher; G. Steinhilber; J. Isaak; N. Pietralla; J. Birkhan; M. L. Cortés; D. H. Jakubassa-Amundsen; I. Jurosevic; P. von Neumann-Cosel; M. Rech; X. Roca-Maza; D. Schneider

doi:10.1016/j.nima.2025.170574

arXiv · 2506.02072

The Electron-Gamma Coincidence Setup DAGOBERT

B. Hesbacher·G. Steinhilber·J. Isaak·N. Pietralla·J. Birkhan·M. L. Cortés·D. H. Jakubassa-Amundsen·I. Jurosevic·P. von Neumann-Cosel·M. Rech·X. Roca-Maza·D. Schneider

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Abstract

The QCLAM electron spectrometer at the S-DALINAC electron accelerator at Technische Universit\"at Darmstadt has been extended by the DAGOBERT $\gamma$-detector array consisting of fast timing and high efficiency LaBr$_3$:Ce detectors to perform electron-gamma coincidence measurements. The functionality of the setup and data acquisition system was demonstrated in a commissioning measurement on $^{12}\textrm{C}$ observing the $4.44\,$MeV and $15.11\,$MeV states. A medium-heavy nucleus, $^{96}\textrm{Ru}$, has been studied for the first time up to excitation energies of $15\,$MeV using the $(e,e'\gamma)$ reaction. In particular, the angular distribution of the $2_1^+$ state and the $\gamma$-decay branching ratios of the mixed-symmetric $2_3^+$ state were observed. DAGOBERT@QCLAM is a new and worldwide unique setup for nuclear structure studies of excitation and decay using purely electromagnetic probes, with a significantly improved sensitivity compared to previous experiments.

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B. Hesbacher, G. Steinhilber, J. Isaak, N. Pietralla, J. Birkhan, M. L. Cortés, D. H. Jakubassa-Amundsen, I. Jurosevic, P. von Neumann-Cosel, M. Rech, X. Roca-Maza, D. Schneider. 2025-06-02. The Electron-Gamma Coincidence Setup DAGOBERT. https://doi.org/10.1016/j.nima.2025.170574

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