AIP Conference Proceedings 2131, 020053 (2019); https://doi.org/10.1063/1.5119506 2131, 020053 © 2019 Author(s). The measurement of diffusion length of demi water by neutron activation of foils vs. Helium-3 neutron detector Cite as: AIP Conference Proceedings 2131, 020053 (2019); https://doi.org/10.1063/1.5119506 Published Online: 29 July 2019 Branislav Vrban, Jakub Lüley, Štefan Čerba, Filip Osuský, and Vladimír Nečas