0000000000376759
AUTHOR
I. D. Alkhazov
Neutron and fragment yields in proton-induced fission of 238U at intermediate energies
The primary fission fragment mass and kinetic energy distributions, and neutron multiplicities as function of fragment mass have been measured in the proton-induced fission of 238 U at energies Ep ¼ 20, 35, 50 and 60 MeV using time-of-flight technique. Pre-scission and post-scission neutron multiplicities have been extracted from double differential distributions. The fragment mass dependence of the post-scission neutron multiplicities reveals the gross nuclear shell structure effect even at the higher proton energies we measured. The yields ofneutron-rich fission products in the fission of 238 U by 25 MeV protons were measured using an ion guide-based isotope separator technique. The resul…
Pre- and post-scission neutron emission in the reaction180Hf(40Ar, fission) atE lab=216 MeV
Neutron and fission fragment spectra following the180Hf(40Ar,f) reaction atE lab=216MeV were measured. The following neutron total, pre- and post-scission multiplicities were extracted:M tot =7.2±1.3,M pre =2.7±0.9,M post =4.5±0.9. The average temperature parameters of the neutron spectra areT pre=(1.63±0.16) MeV andT post=(1.14±0.26)MeV. The mean total kinetic energy of the fission fragments is TKE=(166±10) MeV and the measured width is σTKE=17.3MeV. The width of the fragment mass distribution is σ A =18.3u. The same reaction was analyzed using a modified statistical code which includes nuclear dissipation effects and particle and γ-ray emission in the equilibrium compound nucleus state an…
Fragment mass distribution in superasymmetric region in proton-induced fission of U and Th
Fission fragment mass distributions down to super-asymmetric mass region and both pre- and post-scission neutron multiplicity for238U(p,fission) reaction atEp = 20, 35, 50, 60 MeV and for232Th(p, fission) reaction atEp = 50, 60 MeV were measured using HENDES set-up. The results indicate enhancement for super-asymmetric mass division at intermediate excitation energies.
Position-sensitive neutron detector
Abstract A position-sensitive neutron detector has been developed for use in nuclear physics research. The detector consists of a ∅5.5 cm×100 cm long quartz tube filled with liquid scintillator viewed from both ends by photomultipliers and enclosed in a light-tight titanium container. The properties of the detector were determined both experimentally and by Monte Carlo simulations (EFEN code). A time resolution of 0.4 ns was reached resulting in the position resolution of less than 4 cm. The neutron registration efficiency varies from 36% to 20% within neutron energy range 1–10 MeV and is practically independent of the position along the detector length. Good n–γ separation is achieved for …