An <I>in vivo</I> neutron inelastic scattering activation analysis based on the associated particle timing method is being developed with imaging capability. A proposed imaging system, the Associated Particle Imaging System (APIS) has been described. The APIS is based on identifying the spatial origin, of a measured neutron induced prompt gamma ray, by a position sensitive detection of the associated particle (the helium nucleus). Using the D-D reaction at neutron energy of 2.8 MeV elemental analysis of bulk samples has been demonstrated with the timing technique. Initial results of gamma ray measurements showed a significant reduction in the background. However, losses did occur with the generation of the timing signals, which was improved with the use of a Timing Single Channel Analyser TSCA. The timing method has also been used to measure aluminium in a hand phantom. Unlike some other techniques for measuring aluminium in bone, this technique eliminates the possible interference usually encountered with the presence of phosphorus. The minimum detection limit obtained with the use of the timing showed a significant improvement to that without the timing technique. Further improvements and optimising of the system to higher detection efficiency of the gamma rays have been considered. A detection limit of about 5 mg of aluminium in the hand for a dose of 10 mSv is achievable with the improved system.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:636348 |
| Date | January 1999 |
| Creators | Darko, J. B. |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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