### Abstract

Original language | English |
---|---|

Pages (from-to) | 11–19 |

Number of pages | 8 |

Journal | Annals of Nuclear Energy |

Volume | 46 |

Early online date | 9 Apr 2012 |

DOIs | |

Publication status | Published - Aug 2012 |

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### Keywords

- fission protons
- semi-prompt
- regression
- chi-squared

### Cite this

*Annals of Nuclear Energy*,

*46*, 11–19. https://doi.org/10.1016/j.anucene.2012.023.011

**Regression analysis for a bottom-up approach to analysing semi-prompt fission gamma yields.** / Monville, Maura; Lamb, John; Padovani, Enrico.

Research output: Contribution to journal › Article

*Annals of Nuclear Energy*, vol. 46, pp. 11–19. https://doi.org/10.1016/j.anucene.2012.023.011

}

TY - JOUR

T1 - Regression analysis for a bottom-up approach to analysing semi-prompt fission gamma yields

AU - Monville, Maura

AU - Lamb, John

AU - Padovani, Enrico

PY - 2012/8

Y1 - 2012/8

N2 - We present an empirical model that describes the yield of gamma rays emitted by fission in the time interval from 20 to 958 ns following afission event. The analysis is based on experimental data from neutron-induced fission of 235U and 239Pu. The model is devised by first using regressionanalysis to identify likely patterns in the data and to choose plausible fitting functions. We provide statistical and physical arguments in support of time and energy independence. The intensity of the emitted gamma rays can be described as a bivariate distribution that is the product of independent variates for energy and time. We test several plausible distribution families for the energy and time variates and use maximum likelihood and minimum ¿2 to estimate distribution parameters. Because of the uncertainty in the experimental data, multiple combinations of variate pairs give rise to a surface that plausibly well fits the observations well. The best-fit variate turns out to be lognormal in energy and F in time. The findings illustrated in this paper can be used to simulate gamma ray de-excitation from fission in Monte Carlo codes.

AB - We present an empirical model that describes the yield of gamma rays emitted by fission in the time interval from 20 to 958 ns following afission event. The analysis is based on experimental data from neutron-induced fission of 235U and 239Pu. The model is devised by first using regressionanalysis to identify likely patterns in the data and to choose plausible fitting functions. We provide statistical and physical arguments in support of time and energy independence. The intensity of the emitted gamma rays can be described as a bivariate distribution that is the product of independent variates for energy and time. We test several plausible distribution families for the energy and time variates and use maximum likelihood and minimum ¿2 to estimate distribution parameters. Because of the uncertainty in the experimental data, multiple combinations of variate pairs give rise to a surface that plausibly well fits the observations well. The best-fit variate turns out to be lognormal in energy and F in time. The findings illustrated in this paper can be used to simulate gamma ray de-excitation from fission in Monte Carlo codes.

KW - fission protons

KW - semi-prompt

KW - regression

KW - chi-squared

U2 - 10.1016/j.anucene.2012.023.011

DO - 10.1016/j.anucene.2012.023.011

M3 - Article

VL - 46

SP - 11

EP - 19

JO - Annals of Nuclear Energy

JF - Annals of Nuclear Energy

SN - 0306-4549

ER -