The measurement of diffusion length of demi water by neutron activation of foils vs. Helium-3 neutron detector

The diffusion length L of thermal neutrons has been measured in demi water at room temperature using an PuBe source. The brief theory is outlined, and the results of neutron activation analysis are compared with a first measurement performed by Helium-3 neutron detector. The efforts made are the part of the complex approach aiming to validate nowadays computational tools and methods with measured parameters. (authors)