1. Precision measurement of the electron energy-loss function in tritium and deuterium gas for the KATRIN experiment
- Author
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Aker, M., Beglarian, A., Behrens, J., Berlev, A., Besserer, U., Bieringer, B., Block, F., Bornschein, B., Bornschein, L., Böttcher, M., Brunst, T., Caldwell, T. S., Carney, R. M. D., Chilingaryan, S., Choi, W., Debowski, K., Deffert, M., Descher, M., Barrero, D. Díaz, Doe, P. J., Dragoun, O., Drexlin, G., Edzards, F., Eitel, K., Ellinger, E., Miniawy, A. El, Engel, R., Enomoto, S., Felden, A., Formaggio, J. A., Fränkle, F. M., Franklin, G. B., Friedel, F., Fulst, A., Gauda, K., Gil, W., Glück, F., Groh, S., Grössle, R., Gumbsheimer, R., Hannen, V., Haußmann, N., Heizmann, F., Helbing, K., Hickford, S., Hiller, R., Hillesheimer, D., Hinz, D., Höhn, T., Houdy, T., Huber, A., Jansen, A., Karl, C., Kellerer, J., Kleesiek, M., Klein, M., Köhler, C., Köllenberger, L., Kopmann, A., Korzeczek, M., Kovalík, A., Krasch, B., Krause, H., Kunka, N., Lasserre, T., La Cascio, L., Lebeda, O., Lehnert, B., Le, T. L., Lokhov, A., Machatschek, M., Malcherek, E., Mark, M., Marsteller, A., Martin, E. L., Meier, M., Melzer, C., Menshikov, A., Mertens, S., Mostafa, J., Müller, K., Niemes, S., Oelpmann, P., Parno, D. S., Poon, A. W. P., Poyato, J. M. L., Priester, F., Ranitzsch, P. C. -O., Robertson, R. G. H., Rodejohann, W., Rodenbeck, C., Röllig, M., Röttele, C., Ryšavý, M., Sack, R., Saenz, A., Schäfer, P., Schaller, A., Schimpf, L., Schlösser, K., Schlösser, M., Schlüter, L., Schneidewind, S., Schrank, M., Schulz, B., Schwachtgen, C., Šefčík, M., Seitz-Moskaliuk, H., Sibille, V., Siegmann, D., Slezák, M., Steidl, M., Sturm, M., Sun, M., Tcherniakhovski, D., Telle, H. H., Thorne, L. A., Thümmler, T., Titov, N., Tkachev, I., Trost, N., Urban, K., Valerius, K., Vénos, D., Hernández, A. P. Vizcaya, Weinheimer, C., Welte, S., Wendel, J., Wilkerson, J. F., Wolf, J., Wüstling, S., Xu, W., Yen, Y. -R., Zadoroghny, S., and Zeller, G.
- Subjects
Physics - Instrumentation and Detectors ,High Energy Physics - Experiment - Abstract
The KATRIN experiment is designed for a direct and model-independent determination of the effective electron anti-neutrino mass via a high-precision measurement of the tritium $\beta$-decay endpoint region with a sensitivity on $m_\nu$ of 0.2$\,$eV/c$^2$ (90% CL). For this purpose, the $\beta$-electrons from a high-luminosity windowless gaseous tritium source traversing an electrostatic retarding spectrometer are counted to obtain an integral spectrum around the endpoint energy of 18.6$\,$keV. A dominant systematic effect of the response of the experimental setup is the energy loss of $\beta$-electrons from elastic and inelastic scattering off tritium molecules within the source. We determined the \linebreak energy-loss function in-situ with a pulsed angular-selective and monoenergetic photoelectron source at various tritium-source densities. The data was recorded in integral and differential modes; the latter was achieved by using a novel time-of-flight technique. We developed a semi-empirical parametrization for the energy-loss function for the scattering of 18.6-keV electrons from hydrogen isotopologs. This model was fit to measurement data with a 95% T$_2$ gas mixture at 30$\,$K, as used in the first KATRIN neutrino mass analyses, as well as a D$_2$ gas mixture of 96% purity used in KATRIN commissioning runs. The achieved precision on the energy-loss function has abated the corresponding uncertainty of $\sigma(m_\nu^2)<10^{-2}\,\mathrm{eV}^2$ [arXiv:2101.05253] in the KATRIN neutrino-mass measurement to a subdominant level., Comment: 12 figures, 18 pages; to be submitted to EPJ C
- Published
- 2021
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