skip to main content

DOE PAGESDOE PAGES

Title: An improved numerical method to compute neutron/gamma deexcitation cascades starting from a high spin state

Numerous nuclear processes involve the deexcitation of a compound nucleus through the emission of several neutrons, gamma-rays and/or conversion electrons. The characteristics of such a deexcitation are commonly derived from a total statistical framework often called “Hauser–Feshbach” method. In this work, we highlight a numerical limitation of this kind of method in the case of the deexcitation of a high spin initial state. To circumvent this issue, an improved technique called the Fluctuating Structure Properties (FSP) method is presented. Two FSP algorithms are derived and benchmarked on the calculation of the total radiative width for a thermal neutron capture on 238U. We compare the standard method with these FSP algorithms for the prediction of particle multiplicities in the deexcitation of a high spin level of 143Ba. The gamma multiplicity turns out to be very sensitive to the numerical method. The bias between the two techniques can reach 1.5 γγ/cascade. Lastly, the uncertainty of these calculations coming from the lack of knowledge on nuclear structure is estimated via the FSP method.
Authors:
 [1] ;  [2] ;  [2]
  1. CEA, DEN, DER, SPRC, Saint Paul lez Durance (France); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  2. CEA, DEN, DER, SPRC, Saint Paul lez Durance (France)
Publication Date:
Report Number(s):
LLNL-JRNL-668707
Journal ID: ISSN 0010-4655
Grant/Contract Number:
AC52-07NA27344
Type:
Accepted Manuscript
Journal Name:
Computer Physics Communications
Additional Journal Information:
Journal Volume: 201; Journal Issue: C; Journal ID: ISSN 0010-4655
Publisher:
Elsevier
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Hauser–Feshbach; statistical model; deexcitation; cascade; FIFRELIN
OSTI Identifier:
1342046
Alternate Identifier(s):
OSTI ID: 1247062