Partition of the total excitation energy between complementary fragments
Two methods of the total excitation energy (TXE) partition between complementary fission fragments (FF) are compared: one based on the "classical" hypothesis of prompt neutron emission from fully accelerated FF with both fragments having the same residual nuclear temperature distribution,t...
Saved in:
Main Authors | , , , , |
---|---|
Format | Journal Article |
Language | English |
Published |
08.03.2011
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Two methods of the total excitation energy (TXE) partition between
complementary fission fragments (FF) are compared: one based on the "classical"
hypothesis of prompt neutron emission from fully accelerated FF with both
fragments having the same residual nuclear temperature distribution,the second
one on the systematic behavior of the experimental multiplicity ratio
{\nu}H/({\nu}L+{\nu}H) as a function of the heavy fragment mass number AH,the
complementary FF having different residual temperature distributions.These
methods were applied on six fissioning systems: 233,235U(nth,f), 239Pu(nth,f),
237Np(n5.5MeV,f), 252Cf(SF), 248Cm(SF) and fragment excitation energies,level
density parameters,fragment and fragment pair temperatures were
compared.Limitations of the "classical" TXE partition method are shown.Residual
temperature ratios RT=TL/TH versus AH,local and global parameterizations of
RT(AH) for the neutron induced fissioning systems are obtained.Average values
of quantities characterizing prompt neutron emission are discussed.A linear
decrease of with the mass number of the fissioning nucleus and a linear
decrease of the average C parameter with the fissility parameter is
obtained.Point by Point (PbP) model calculations validate the RT(AH)
parameterizations.The multi-parametric matrix {\nu}(A,TKE) as well as prompt
neutron and gamma-ray emission quantities as a function of fragment mass,total
average prompt neutron multiplicity and spectrum and prompt neutron
multiplicity distribution P({\nu}) were calculated.The global RT(AH)
parameterization extends the use of the PbP model to predict prompt neutron
emission quantities for fissioning systems without experimental data.An
explanation of the less pronounced sawtooth shape of {\nu}(A) and the increase
of {\nu}(A) with incident neutron energy only for heavy fragments is given and
exemplified by quantitative results of the PbP model. |
---|---|
DOI: | 10.48550/arxiv.1103.1574 |