scholarly journals FAST ROSSI-ALPHA MEASUREMENTS OF PLUTONIUM USING ORGANIC SCINTILLATORS

2021 ◽  
Vol 247 ◽  
pp. 09025
Author(s):  
M.Y. Hua ◽  
C.A. Bravo ◽  
A.T. MacDonald ◽  
J.D. Hutchinson ◽  
G.E. McKenzie ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Confidence Intervals ◽  
Decay Constant ◽  
Detection System ◽  
Prompt Neutron ◽  
Neutron Decay ◽  
Organic Scintillator ◽  
Slowing Down ◽  
Organic Scintillators

In this work, Rossi-alpha measurements were simultaneously performed with a 3He-based detection system and an organic scintillator-based detection system. The assembly is 15 kg of plutonium (93 wt% 239Pu) reflected by copper and moderated by lead. The goal of Rossi-alpha measurements is to estimate the prompt neutron decay constant, alpha. Simulations estimate keff = 0:624 and α = 52:3 ± 2:5 ns for the measured assembly. The organic scintillator system estimated α = 47:4 ± 2:0 ns, having a 9.37% error (though the 1.09 standard deviation confidence intervals overlapped). The 3He system estimated α = 37 μs. The known slowing down time of the 3He system is 35-40 μs, which means the slowing down time dominates and obscures the prompt neutron decay constant. Subsequently, the organic scintillator system should be used for assemblies with alpha much less than 35 μs.

Measurement of Prompt Neutron Decay Constant of CFBR-II at Near Delayed Criticality Using Randomly Pulsed Neutron Method

2013 ◽  
Author(s):  
Lingli Song ◽  
Jiansheng Li ◽  
Haojun Zhou ◽  
Yu Jin
Keyword(s):  
Liquid Scintillation ◽  
Decay Constant ◽  
Detection System ◽  
Prompt Neutron ◽  
Neutron Decay ◽  
Timing Uncertainty ◽  
Neutron Method ◽  
Pulsed Neutron ◽  
Liquid Scintillation Detector ◽  
Good Agreement

Prompt neutron decay constant of CFBR-II (China’s Fast Burst Reactor) was measured by the randomly pulsed neutron method when the reactor was at the reactivity of −0.1$. A liquid scintillation detector was used to detect the leakage neutrons and the timing uncertainty of the detection system was less than 3ns. The detector and the Cf-252 fast ionization chamber were placed at several positions. Totally 5 prompt neutron timing distribution curves were obtained and the prompt neutron decay constant was 0.610us−1 in average with the uncertainty of 0.030us−1, which was in good agreement with the M.C. calculation.

scholarly journals Measurement of Prompt Neutron Decay Constant in Delayed Critical State of Heavily Reflected Reactor

1967 ◽  
Vol 4 (9) ◽  
pp. 462-467
Author(s):  
Yoshihiko KANEKO ◽  
Fujiyoshi AKINO ◽  
Ryòsuke KUROKAWA ◽  
Kenji SUMITA
Keyword(s):  
Critical State ◽  
Decay Constant ◽  
Prompt Neutron ◽  
Neutron Decay

Adaptive Estimation of the Prompt-Neutron Decay Constant Using Autoregressive Moving Average Modeling

1996 ◽  
Vol 122 (1) ◽  
pp. 68-78
Author(s):  
Nela Zavaljevski ◽  
Ljiljana Kostić ◽  
Milan Pešić ◽  
Aleksandar Zavaljevski
Keyword(s):  
Decay Constant ◽  
Adaptive Estimation ◽  
Moving Average ◽  
Prompt Neutron ◽  
Neutron Decay ◽  
Autoregressive Moving Average

Measurement of Prompt Neutron Decay Constant and Large Subcriticality by the Feynman-α Method

1990 ◽  
Vol 104 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Tsuyoshi Misawa ◽  
Seiji Shiroya ◽  
Keiji Kanda
Keyword(s):  
Decay Constant ◽  
Prompt Neutron ◽  
Neutron Decay
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