Background Model for the Majorana Demonstrator

• Published in: Physics procedia 2015-06, Vol.61
• Main Authors: Cuesta, C., Abgrall, N., Aguayo, Estanislao, Avignone, Frank T., Barabash, Alexander S., Bertrand, F., Boswell, M., Brudanin, V., Busch, Matthew, Byram, D., Caldwell, A. S., Chan, Yuen-Dat, Christofferson, Cabot-Ann, Combs, Dustin C., Detwiler, Jason A., Doe, Peter J., Efremenko, Yuri, Egorov, Viatcheslav, Ejiri, H., Elliott, S. R., Fast, James E., Finnerty, P., Fraenkle, Florian, Galindo-Uribarri, A., Giovanetti, G. K., Goett, J., Green, M. P., Gruszko, J., Guiseppe, Vincente, Gusev, K., Hallin, A. L., Hazama, R., Hegai, A., Henning, Reyco, Hoppe, Eric W., Howard, Stanley, Howe, M. A., Keeter, K., Kidd, M. F., Kochetov, Oleg, Konovalov, S., Kouzes, Richard T., Laferriere, Brian D., Leon, Jonathan D., Leviner, L., Loach, J. C., MacMullin, J., MacMullin, S., Martin, R. D., Meijer, S. J., Mertens, S., Nomachi, Masaharu, Orrell, John L., O'Shaughnessy, C., Overman, Nicole R., Phillips, D., Poon, Alan, Pushkin, K., Radford, D. C., Rager, J., Rielage, Keith, Robertson, R. G. H., Romero-Romero, E., Ronquest, M. C., Schubert, Alexis G., Shanks, B., Shima, T., Shirchenko, M., Snavely, Kyle J., Snyder, N., Suriano, Anne-Marie, Thompson, J., Timkin, V., Tornow, Werner, Trimble, J. E., Varner, R. L., Vasilyev, Sergey, Vetter, Kai, Vorren, Kris R., White, Brandon R., Wilkerson, J. F., Wiseman, C., Xu, W., Yakushev, E., Young, A., Yu, Chang-Hong, Yumatov, Vladimir
• Format: Article
• Language: English
• ISSN: 1875-3892; 1875-3892

The Majorana Collaboration is constructing a prototype system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment to search for neutrinoless double-beta (0v BB) decay in 76Ge. In view of the requirement that the next generation of tonne-scale Ge-based 0vBB-decay experiment be capable of probing the neutrino mass scale in the inverted-hierarchy region, a major goal of theMajorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using Geant4 simulations of the different background components whose purity levels are constrained from radioassay measurements.