<p>A series of nuclear fission experiments have been performed in the intermediate energy range. The dynamics of the fission process have been studied by means of detection of neutrons emitted from compound nuclei formed by ion beams of protons, α-particles, and <sup>12</sup>C-ions, all at a beam energy of 100 MeV. The neutron emission data have been interpreted using a statistical model analysis, and the fission time scale has been found to vary between 6.4 and 170ⅹ10<sup>-21 </sup>s.</p><p>Neutron-induced fission cross section measurements have been performed on targets of <sup>208</sup>Pb, <sup>209</sup>Bi, and <sup>238</sup>U. The results have been compared with other measurements as well as with model calculations and evaluations. The comparisons agreed reasonably well with previous measurements, but disagreed substantially both with calculations and evaluations. The neutron flux in the neutron-induced fission was determined relative to the <i>np</i>-scattering cross section which was measured simultaneously.</p><p>The <i>np</i>-scattering cross section has been measured with an unprecedented precision. Using a normalization procedure which takes advantage of the total <i>np</i> cross section, which has been determined with great precision, differential <i>np</i> cross sections have been presented in the angular range 74° to 180° at 96 MeV and 72° to 180° at 162 MeV. They were found to disagree with as much as 10—15 % compared with older measurements in the world data base, and with Partial Wave Analysis solutions. The data are, however, in agreement with another recent, high-quality measurement.</p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:uu-2106 |
| Date | January 2002 |
| Creators | Elmgren, Klas |
| Publisher | Uppsala University, Department of Neutron Research, 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 ; 724 |
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