Gamma-induced background in the KATRIN main spectrometer K. Altenmüller, M. Arenz, W.-J. Baek, M. Beck, A. Beglarian, J. Behrens, A. Berlev, U. Besserer, K. Blaum, F. Block et al. (116 more) Eur. Phys. J. C, 79 9 (2019) 807 Published online: 28 September 2019 DOI: 10.1140/epjc/s10052-019-7320-4