<p>Neutron-carbon interactions have been studied with a focus on charged-particle production of relevance to radiation protection and medical applications, such as cancer therapy. The measurements have been performed using the particle-detection setup, MEDLEY, and the 96 MeV neutron beam at the The Svedberg Laboratory in Uppsala.</p><p>Double-differential cross sections of inclusive charged-particle production are compared with recent calculations from models based on the GNASH code including direct, preequilibrium and compound processes. For protons, the shapes of the cross-section spectra are reasonably well described by the calculations. For the other particles- <i>d</i>, <i>t</i>, <sup>3</sup>He and α- there are important discrepancies, in particular for <sup>3</sup>He-ions and α-particles, concerning both shape and magnitude of the spectra.</p><p>Using the new cross sections, partial as well as total KERMA coefficients have been determined. The coefficients have also been compared to previous experimental results and model calculations. The <i>p</i>, <i>d</i> and <i>t</i> KERMA coefficients are in good agreement with those from a previous measurement. For the helium isotopes, there are no previous measurements at this energy. The KERMA coefficients are considerably higher (by up to 30%) than those predicted by the calculations.</p><p>The KERMA results indicate that protons and α -particles are the main contributors to the dose. A 6x6x6 cm<sup>3</sup> carbon phantom, exposed to a broad and a pencil-like beam, is used for the computation of the absorbed doses deposited by these two particles in spheres of 1 μm in diameter, located at various positions in the phantom. The maximum doses are deposited at ~3 cm from the surface of neutron impact for protons and within 1 cm for α-particles. For the pencil beam, deposited doses are spread over regions of ~1.5 cm and ~300 μm transverse to the beam for protons and α-particles, respectively. The results are consistent with previous integral measurements at lower energies.</p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:uu-4700 |
| Date | January 2004 |
| Creators | Bergenwall, Bel E. |
| Publisher | Uppsala University, Department of Nuclear and Particle Physics, Uppsala : Acta Universitatis Upsaliensis |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, text |
| Relation | Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1104-232X ; 1049 |
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