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Title: Pion interactions with light nuclei and applications to radiotherapy
Author: Brenner, David Jonathan
ISNI:       0000 0001 3478 8324
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 1979
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In the light of the current interest in negative pion radiotherapy this work attempts to obtain particle spectra after stopped negative pion absorption in oxygen. These data are vital prerequisites both for theoretical radiobiological predictions of cell damage and also for pion therapy treatment planning. The problem is approached in two ways: firstly a measurement of the neutron spectrum in a stopping pion field; secondly an attempt to make theoretical predictions of the energy spectra of particles emitted after stopped pion absorption based on a more realistic nuclear model than previously used. The experiment, performed at the Rutherford Laboratory, uses a multiple foil activation technique. Neutron spectra from the pion interactions and also from background sources were measured. The results are comparable with recent time-of-flight data. Given various improvements in the experimental conditions which would be available in a clinical facility it is considered that the technique is a potentially useful tool for routine dosimetry. The theoretical work was undertaken in the light of the failure of statistical Monte-Carlo methods to reproduce the experimental data. The underlying assumption is that stopped pion absorption on oxygen may be treated as occurring on an a-cluster and, using a plane-wave impulse approximation,particle spectra are calculated. Total absorption widths are well reproduced but the spectra differ from experiment particularly at low energies. A method of considering residual interactions with the nucleus is described which has the potential to treat the low energy particles and also final channels not expected as a result of a single interaction.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available