Böhnel multiplicity formulae beyond the point model
Paper in proceedings, 2019

Passive methods of nuclear safeguards determine the important parameters of an unknown sample from the statistics of the detection of the neutrons emitted from the item. These latter are mostly due to spontaneus fissions (and (α,n) reactions, neglected here), enhanced by a slight internal multiplication before leaking out. Following the original work of Böhnel [1], the methodology of traditional multiplicity counting is based on the first three factorial moments of the number of neutrons, emitted from the sample due to one source event. These “Böhnel moments” were derived in the so-called “point model”, in which no space-dependence is assumed, rather a uniform first collision probability is assumed for each neutron, irrespective of the position of its birth and its velocity direction. The purpose of the present work is to derive the same factorial moments in a one-speed space-dependent model, in which the position and direction of the neutrons is accounted for, but (similarly to the original Böhnel model), no energy dependence is assumed.

Non-point model

Factorial moments

Böhnel formulae

Multiplicity counting

Author

Imre Pazsit

Chalmers, Physics, Subatomic and Plasma Physics

L. Pal

Hungarian Academy of Sciences

Andreas Enqvist

University of Florida

International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2019

2856-2865

2019 International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2019
Portland, USA,

Subject Categories

Accelerator Physics and Instrumentation

Subatomic Physics

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