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Now showing 1 - 3 of 3
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    Splitting of the magnetic monopole pair-creation energy in spin ice
    (Bristol : IOP Publ., 2020) Hornung, J.; Gottschall, T.; Opherden, L.; Antlauf, M.; Schwarz, M.; Kroke, E.; Herrmannsdörfer, T.; Wosnitza, J.
    The thermodynamics in spin-ice systems are governed by emergent magnetic monopole excitations and, until now, the creation of a pair of these topological defects was associated with one specific pair-creation energy. Here, we show that the electric dipole moments inherent to the magnetic monopoles lift the degeneracy of their creation process and lead to a splitting of the pair-creation energy. We consider this finding to extend the model of magnetic relaxation in spin-ice systems and show that an electric dipole interaction in the theoretically estimated order of magnitude leads to a splitting which can explain the controversially discussed discrepancies between the measured temperature dependence of the magnetic relaxation times and previous theory. By applying our extended model to experimental data of, various spin-ice systems, we show its universal applicability and determine a dependence of the electric dipole interaction on the system parameters, which is in accordance with the theoretical model of electric dipole formation. © 2020 The Author(s). Published by IOP Publishing Ltd.
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    Characterization of inverted coaxial 76 Ge detectors in GERDA for future double- β decay experiments
    (Berlin ; Heidelberg : Springer, 2021) Agostini, M.; Araujo, G.; Bakalyarov, A.M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Bettini, A.; Bezrukov, L.; Wojcik, M.; Yanovich, E.; Zatschler, B.; Zhitnikov, I.; Zhukov, S.V.; Zinatulina, D.; Zschocke, A.; Zsigmond, A.J.; Zuber, K.; Zuzel, G.; Biancacci, V.; Bossio, E.; Bothe, V.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; Comellato, T.; D'Andrea, V.; Demidova, E.V.; Marco, N.D.; Doroshkevich, E.; Fischer, F.; Fomina, M.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hemmer, S.; Hofmann, W.; Huang, J.; Hult, M.; Inzhechik, L.V.; Janicskó Csáthy, J.; Jochum, J.; Junker, M.; Kazalov, V.; Kermaïdic, Y.; Khushbakht, H.; Kihm, T.; Kirpichnikov, I.V.; Klimenko, A.; Kneißl, R.; Knöpfle, K.T.; Kochetov, O.; Kornoukhov, V.N.; Krause, P.; Kuzminov, V.V.; Laubenstein, M.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Manzanillas, L.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Müller, Y.; Nemchenok, I.; Pandola, L.; Pelczar, K.; Pertoldi, L.; Piseri, P.; Pullia, A.; Ransom, C.; Rauscher, L.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Schönert, S.; Schreiner, J.; Schütt, M.; Schütz, A.-K.; Schulz, O.; Schwarz, M.; Schwingenheuer, B.; Selivanenko, O.; Shevchik, E.; Shirchenko, M.; Shtembari, L.; Simgen, H.; Smolnikov, A.; Stukov, D.; Vasenko, A.A.; Veresnikova, A.; Vignoli, C.; von Sturm, K.; Wester, T.; Wiesinger, C.
    Neutrinoless double-β decay of 76Ge is searched for with germanium detectors where source and detector of the decay are identical. For the success of future experiments it is important to increase the mass of the detectors. We report here on the characterization and testing of five prototype detectors manufactured in inverted coaxial (IC) geometry from material enriched to 88% in 76Ge. IC detectors combine the large mass of the traditional semi-coaxial Ge detectors with the superior resolution and pulse shape discrimination power of point contact detectors which exhibited so far much lower mass. Their performance has been found to be satisfactory both when operated in vacuum cryostat and bare in liquid argon within the Gerda setup. The measured resolutions at the Q-value for double-β decay of 76Ge (Qββ = 2039 keV) are about 2.1 keV full width at half maximum in vacuum cryostat. After 18 months of operation within the ultra-low background environment of the GERmanium Detector Array (Gerda) experiment and an accumulated exposure of 8.5 kg⋅year, the background index after analysis cuts is measured to be 4.9+7.3−3.4×10−4 counts/(keV⋅kg⋅year) around Qββ. This work confirms the feasibility of IC detectors for the next-generation experiment Legend.
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    Calibration of the GERDA experiment
    (Berlin ; Heidelberg : Springer, 2021) Agostini, M.; Araujo, G.; Bakalyarov, A.M.; Balata, M.; Barabanov, I.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Bettini, A.; Bezrukov, L.; Wiesinger, C.; Wojcik, M.; Yanovich, E.; Zatschler, B.; Zhitnikov, I.; Zhukov, S.V.; Zinatulina, D.; Zschocke, A.; Zsigmond, A.J.; Zuber, K.; Biancacci, V.; Zuzel, G.; Bossio, E.; Bothe, V.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; Comellato, T.; D'Andrea, V.; Demidova, E.V.; Marco, N.D.; Doroshkevich, E.; Fischer, F.; Fomina, M.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hemmer, S.; Hiller, R.; Hofmann, W.; Huang, J.; Hult, M.; Inzhechik, L.V.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kazalov, V.; Kermaïdic, Y.; Khushbakht, H.; Kihm, T.; Kirpichnikov, I.V.; Klimenko, A.; Kneißl, R.; Knöpfle, K.T.; Kochetov, O.; Kornoukhov, V.N.; Krause, P.; Kuzminov, V.V.; Laubenstein, M.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Manzanillas, L.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Müller, Y.; Nemchenok, I.; Pandola, L.; Pelczar, K.; Pertoldi, L.; Piseri, P.; Pullia, A.; Ransom, C.; Rauscher, L.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Schönert, S.; Schreiner, J.; Schütt, M.; Schütz, A.-K.; Schulz, O.; Schwarz, M.; Schwingenheuer, B.; Selivanenko, O.; Shevchik, E.; Shirchenko, M.; Shtembari, L.; Simgen, H.; Smolnikov, A.; Stukov, D.; Vasenko, A.A.; Veresnikova, A.; Vignoli, C.; von Sturm, K.; Wester, T.
    The GERmanium Detector Array (Gerda) collaboration searched for neutrinoless double-β decay in 76Ge with an array of about 40 high-purity isotopically-enriched germanium detectors. The experimental signature of the decay is a monoenergetic signal at Qββ =2039.061(7) keV in the measured summed energy spectrum of the two emitted electrons. Both the energy reconstruction and resolution of the germanium detectors are crucial to separate a potential signal from various backgrounds, such as neutrino-accompanied double-β decays allowed by the Standard Model. The energy resolution and stability were determined and monitored as a function of time using data from regular 228Th calibrations. In this work, we describe the calibration process and associated data analysis of the full Gerda dataset, tailored to preserve the excellent resolution of the individual germanium detectors when combining data over several years.