Sampling the Number of Neutrons Emitted per Fission

Cullen, D E

Lawrence Livermore National Laboratory

关键词: Fission;    Prompt Neutrons;    Sampling;    Neutrons;    22 General Studies Of Nuclear Reactors;   

DOI  :  10.2172/897928
RP-ID  :  UCRL-TR-222526
RP-ID  :  W-7405-ENG-48
RP-ID  :  897928

美国|英语

来源: UNT Digital Library

【 摘 要 】

I define in detail the model used to sample the number of prompt neutrons emitted in fission; this description is based on publications defining the model [1] as well as publications comparing the model to experimental measurements [2]. The model described in these publications is exactly what the TART [3] Monte Carlo transport code uses. Based on comparisons between TART [3] and MCNPX [4], it is obvious that at the time this report was published these two computer codes are not using the same model, and the results significantly differ. It is my hope that this report will contribute toward better understanding of this model, and hopefully eventually to agreement between TART and MCNPX results. Partial success has already been achieved in the sense that based upon reading a preliminary version of this report, John Hendrichs [5], one author of MCNPX, acknowledged that the sources of differences as described in this report demonstrate an error in MCNPX (John even offered me the traditional $20 reward for reporting an error in MCNPX; I declined to accept). John is presently updating MCNPX to eliminate these sources of differences; hopefully in the not too distant future this correction will be available in MCNPX, and we will obtain agreement between TART and MCNPX, which is the ultimate objective of this report.