Search Results
Cryogenic characterization of a LiAlO 2 crystal and new results on spin-dependent dark matter interactions with ordinary matter: CRESST Collaboration
2020, Abdelhameed, A.H., Angloher, G., Bauer, P., Bento, A., Bertoldo, E., Breier, R., Bucci, C., Canonica, L., D’Addabbo, A., Di Lorenzo, S., Erb, A., Feilitzsch, F.V., Iachellini, N.F., Fichtinger, S., Fuchs, D., Fuss, A., Ghete, V.M., Garai, A., Gorla, P., Hauff, D., Ješkovský, M., Jochum, J., Kaizer, J., Kaznacheeva, M., Kinast, A., Kluck, H., Kraus, H., Langenkämper, A., Mancuso, M., Mokina, V., Mondragon, E., Olmi, M., Ortmann, T., Pagliarone, C., Palušová, V., Pattavina, L., Petricca, F., Potzel, W., Povinec, P., Pröbst, F., Reindl, F., Rothe, J., Schäffner, K., Schieck, J., Schipperges, V., Schmiedmayer, D., Schönert, S., Schwertner, C., Stahlberg, M., Stodolsky, L., Strandhagen, C., Strauss, R., Usherov, I., Wagner, F., Willers, M., Zema, V., Zeman, J., Brützam, M., Ganschow, S.
In this work, a first cryogenic characterization of a scintillating LiAlO 2 single crystal is presented. The results achieved show that this material holds great potential as a target for direct dark matter search experiments. Three different detector modules obtained from one crystal grown at the Leibniz-Institut für Kristallzüchtung (IKZ) have been tested to study different properties at cryogenic temperatures. Firstly, two 2.8 g twin crystals were used to build different detector modules which were operated in an above-ground laboratory at the Max Planck Institute for Physics (MPP) in Munich, Germany. The first detector module was used to study the scintillation properties of LiAlO 2 at cryogenic temperatures. The second achieved an energy threshold of (213.02 ± 1.48) eV which allows setting a competitive limit on the spin-dependent dark matter particle-proton scattering cross section for dark matter particle masses between 350MeV/c2 and 1.50GeV/c2. Secondly, a detector module with a 373 g LiAlO 2 crystal as the main absorber was tested in an underground facility at the Laboratori Nazionali del Gran Sasso (LNGS): from this measurement it was possible to determine the radiopurity of the crystal and study the feasibility of using this material as a neutron flux monitor for low-background experiments. © 2020, The Author(s).
Calibration of the GERDA experiment
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.
Lithium-Containing Crystals for Light Dark Matter Search Experiments
2020, Bertoldo, E., Abdelhameed, A.H., Angloher, G., Bauer, P., Bento, A., Breier, R., Bucci, C., Canonica, L., D’Addabbo, A., Di Lorenzo, S., Erb, A., Feilitzsch, F.V., Ferreiro Iachellini, N., Fichtinger, S., Fuchs, D., Fuss, A., Gorla, P., Hauff, D., Ješkovský, M., Jochum, J., Kaizer, J., Kinast, A., Kluck, H., Kraus, H., Langenkämper, A., Mancuso, M., Mokina, V., Mondragon, E., Olmi, M., Ortmann, T., Pagliarone, C., Palušová, V., Pattavina, L., Petricca, F., Potzel, W., Povinec, P., Pröbst, F., Reindl, F., Rothe, J., Schäffner, K., Schieck, J., Schipperges, V., Schmiedmayer, D., Schönert, S., Schwertner, C., Stahlberg, M., Stodolsky, L., Strandhagen, C., Strauss, R., Usherov, I., Willers, M., Zema, V., Zeman, J., Brützam, M., Ganschow, S.
In the current direct dark matter search landscape, the leading experiments in the sub-GeV mass region mostly rely on cryogenic techniques which employ crystalline targets. One attractive type of crystals for these experiments is those containing lithium, due to the fact that 7Li is an ideal candidate to study spin-dependent dark matter interactions in the low mass region. Furthermore, 6Li can absorb neutrons, a challenging background for dark matter experiments, through a distinctive signature which allows the monitoring of the neutron flux directly on site. In this work, we show the results obtained with three different detectors based on LiAlO2, a target crystal never used before in cryogenic experiments.
Characterization of inverted coaxial 76 Ge detectors in GERDA for future double- β decay experiments
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.