Gamma-induced background in the KATRIN main spectrometer

0509890 - ÚJF 2020 RIV DE eng J - Journal Article
Altenmuller, K. - Arenz, M. - Baek, W. -J. - Beck, M. - Beglarian, A. - Behrens, J. - Dragoun, Otokar - Kovalík, Alojz - Lebeda, Ondřej - Ryšavý, Miloš - Suchopár, Martin - Vénos, Drahoslav … Total 126 authors
Gamma-induced background in the KATRIN main spectrometer.
European Physical Journal C. Roč. 79, č. 9 (2019), č. článku 807. ISSN 1434-6044. E-ISSN 1434-6052
R&D Projects: GA MŠMT LM2015056; GA MŠMT LTT18021; GA MŠMT LTT19005
Institutional support: RVO:61389005
Keywords : KATRIN spectrometer * rate of background * main spectrometer
OECD category: Particles and field physics
Impact factor: 4.389, year: 2019
Method of publishing: Open access
https://doi.org/10.1140/epjc/s10052-019-7320-4

he KATRIN experiment aims to measure the effective electron antineutrino mass m nu over bar e with a sensitivity of 0.2eV/c2 using a gaseous tritium source combined with the MAC-E filter technique. A low background rate is crucial to achieving the proposed sensitivity, and dedicated measurements have been performed to study possible sources of background electrons. In this work, we test the hypothesis that gamma radiation from external radioactive sources significantly increases the rate of background events created in the main spectrometer (MS) and observed in the focal-plane detector. Using detailed simulations of the gamma flux in the experimental hall, combined with a series of experimental tests that artificially increased or decreased the local gamma flux to the MS, we set an upper limit of 0.006count/s (90% C.L.) from this mechanism. Our results indicate the effectiveness of the electrostatic and magnetic shielding used to block secondary electrons emitted from the inner surface of the MS.
Permanent Link: http://hdl.handle.net/11104/0300479