Fission Neutrons

Introduction.- Experiments.- 2. Microscopic experiments.- Method based on fission event counting.- Neutron spectroscopy by Time of Flight Method (TOF).- Time correlated background.- Time shift in neutron detector.- Neutron-gamma discrimination and its influence on results.- Measurement of the neutron detector efficiency.- Time resolution and “bin” corrections.- Additional time spread for “solid sample” experiment at low input energy.- Possible distortion factors in 2^nd type experiment.- The calculation of the detector efficiency with high accuracy up to 20MeV.- Correction for neutron scattering in FF detector.- Multi detectors systems and “cross talk correction”.- Macroscopic experiments.- 3. Microscopic spectra evaluation. Semi-empirical modeling.- Maxwellian function and Terrell’s systematic.- ²⁵²Cf spectrum evaluation.- Two Watt Spectra (TWS) approach.- Maxwellian together with power expansion for ²³⁵U(th).- Scale Method.- PFNS for multiple chance fission.- 4. Models for neutron emission in fission.- Basis for theoretical modeling.- True or plausible results?.- Model realized in code FINE (FIssion Neutron Emission).- Estimation of the two-dimensional Y(A,TKE) distribution.- Neutron emission from excited fragments.- Monte Carlo simulation of energy-angular distribution. Verification.- Level Density verification.- Comparison experimental and calculated results.- 5. Achievements and still open problems.- Real achievements.- Mechanism of neutron emission in fission.- Left-right and angular effects for fission neutron emission at 0.5 MeV input energy.- Contradiction between Microscopic and Macroscopic experiments (Mic-Mac problem).- New experimental proposal.