Some studies of the interaction of fast neutrons with complex nuclei

Brown, Gordon (1957) Some studies of the interaction of fast neutrons with complex nuclei. PhD thesis, University of Glasgow.

Abstract

In Chapter I a review is made of the theoretical and experimental investigations of the mode of interaction of nucleons with nuclei. It is concluded that many experimental results, on the nuclear reactions induced in nuclei by nucleons with intermediate energies, might be interpreted using a nuclear model basically similar to that which has been applied successfully to the reactions induced by nucleons of high energy. The calculation of the cross-sections for the reactions induced in nuclei by nucleons with intermediate energies, is reported in Chapter II, It is shown that it is possible to calculate these cross-sections using a simple nuclear model which is basically similar to that used for nucleons of high energy. The derivation of the formulae for the total cross-section for the collision of an incident nucleon with an individual nucleon of a Fermi gas of nucleons, given in 3(a), was performed by Dr. H. Muirhead with assistance from the author. The responsibility for all other calculations, namely those of the angular distribution of the nucleons resulting from this collision Process, of the level densities of excited nuclei and of the applications of this model, is equally that of Dr. H, huirhead and the author. An experimental investigation of the angular distribution of the protons emitted in reactions of the type [z]N[A] (n,p)[z-1]N[A] induced by neutrons with an energy of 13.2 MeV, is reported in Chapter III. Nuclear emulsions were used to detect these protons. This work is original. Unfortunately, in these experiments it was not possible to employ professional scanners to advantage, and consequently the majority of the arduous scanning of these emulsions and the measurements involved has been performed by physicists, Tne apparatus which has been used in these investigations was designed in collaboration with Mr. G.C. Morrison. The measurements made for the protons emitted in the reaction [26]Fe[56](n,p)[25]Mn[56] and an initial analysis of this data were also the responsibility of Mr. G.C, Morrison and the author, A satisfactory analysis of this data was not possible until a method of correction for the loss in energy of the protons produced in a semi-thick target had been devised, A method of correction was suggested and applied by the author. The further analyses of (n,p) reactions, namely those of [13]AI[27](n,p)[12]Mg[27] and [45]Rh[103](n,p)[44]Ru[103] were performed solely by the author. The cross-sections for the emission of protons in these reactions have been determined, and these values have been compared with the predictions of the model discussed in Chapter II, In this work the author was assisted by Mr. W.T. Morton. In Chapter IV the calculation of the cross-sections for the interaction of neutrons of low energies ( ? 4 MeV) with nuclei is discussed. These cross-sections have been Calculated using a potential of step form and the results have been compared with those obtained using a square well potential. These calculations were performed solely by the author. Finally the information which has been derived from this research is discussed in Chapter V. Suggestions are made for its extension.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: P I Dee
• Keywords: Nuclear physics and radiation, Atomic physics
• Date of Award: 1957
• Depositing User: Enlighten Team
• Unique ID: glathesis:1957-73547
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73547