Direct Measurement of Neutron-Neutron Scattering
In order to resolve long-standing discrepancies in indirect measurements of the neutron-neutron scattering length ann and contribute to solving the problem of the charge symmetry of the nuclear force, the collaboration DIANNA (Direct Investigation of ann Association) plans to measure the neutron-neutron scattering cross section σnn. The key issue of our approach is the use of the through-channel in the Russia reactor YAGUAR with a peak neutron flux of 1018 /cm2/s. The proposed experimental setup is described. Results of calculations are presented to connect σnn with the nn-collision detector count rate and the neutron flux density in the reactor channel. Measurements of the thermal neutron fields inside polyethylene converters show excellent prospects for the realization of the direct nn-experiment.
