Open Access Te Herenga Waka-Victoria University of Wellington
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Neutron Cross Section Measurement Using the Associated Particle Technique

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posted on 2021-11-08, 00:24 authored by Johnson, Peter B

The associated particle technique is applied to the D(d.n) He3 reaction, in order to produce a tagged neutron beam of accurately known energy, flux, and direction. The incident deuteron beam is obtained from a 400 Kv positive ion Van de Graaff accelerator. A description is given of the design of a uniform field sector magnet and other equipment associated with the stabilization and calibration of the energy of the incident deuteron beam. A versatile n-He3 coincidence system is described. The use of a silicon surface barrier detector with a thin nickel foil window enables complete resolution of the He3 peak with consequent improved neutron flux determination. The tagged neutron beam is used to measure the absolute neutron cross sections of the K39 (n,p) A39 and K39 (n, alpha) Cl36 reactions at a neutron energy of 2.46 Mev. The results obtained, (95 plus-minus 4) mb and (6.2 plus-minus 1) mb respectively, are compared with values obtained by other workers, and with theoretical predictions.


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Date of Award



Te Herenga Waka—Victoria University of Wellington

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Author Retains Copyright

Degree Discipline


Degree Grantor

Te Herenga Waka—Victoria University of Wellington

Degree Level


Degree Name

Doctor of Philosophy

Victoria University of Wellington Item Type

Awarded Doctoral Thesis



Victoria University of Wellington School

School of Chemical and Physical Sciences


Chapman, N G; Walker, D