Angular correlations in the prompt neutron emission of spontaneous fission of 252Cf

Neutron angular distributions in spontaneous fission of 252Cf are investigated. The CORA experiment, performed at IPHC Strasbourg, aims at elucidating neutron emission mechanisms in the fission process. The experimental setup is composed of the angle-sensitive twin ionisation chamber CODIS for the detection of fission fragments and the DEMON neutron detector assembly. The development of a simulation toolkit based on GEANT4 and MENATE_R is described, adapted as a strategy to investigate the influence of experimental conditions on the observed properties of neutrons emitted. Besides the kinematic neutron anisotropy in the laboratory system due to neutron evaporation from moving fragments, two additional effects are discussed which may have an influence on the angular distributions of neutrons: scission neutrons and dynamic neutron emission anisotropy in the CM system of fragments due to the spin carried by fragments. A new analysis method is presented to disentangle the dynamic anisotropy from the other effects in an independent way. For the dynamic anisotropy only an upper limit could be found. Results for the angular correlation (n,n) between two evaporated neutrons and the correlation (n,LF) between an evaporated neutron and the Light Fragment direction of flight are reported.JRC.G.2-Standards for Nuclear Safety, Security and Safeguard

Neutron emission anisotropy in fission

Experimental neutron angular distributions are investigated in the spontaneous fission process of 252Cf. The CORA experiment, presented in this paper, has the aim to study neutron angular correlations in order to elucidate the neutron emission mechanisms in the fission process. The experimental setup is composed by the CODIS fission chamber and the DEMON neutron multidetector. The development of a simulation toolkit based on GEANT4 and ROOT adopted as strategy to investigate the emission of the neutrons is described. Preliminary results on the sources of the anisotropy, scission neutron emission and/or dynamical anisotropy, are shown.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

The Soviet American Gallium Experiment (SAGE)

A radiochemical experiment using the reaction v/sub e/ = /sup 71/Ga + e/sup e/ to determine the integral flux of low-energy neutrinos from the sun is currently under preparation at the Baksan Neutrino Observatory in the USSR. Measurements are scheduled to commence by late 1988 using /approximately/30 tonnes of metallic gallium. With this amount of gallium it should be possible to obtain a fractional statistical accuracy of 12 to 15% after one year (assuming the standard solar model neutrino flux). While initial measurements are in progress, installation of the remaining 30 tonnes of gallium will proceed in order to perform the full 60 tonne experiment