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| 2. |
- Mermod, P., et al.
(författare)
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Kerma coefficients for neutron scattering on (12)c and O-16 at 96 mev
- 2007
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Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 126:1-4, s. 113-118
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Tidskriftsartikel (refereegranskat)abstract
- Recently, many new applications of fast neutrons are emerging or under development, like dose effects due to cosmic ray neutrons for airplane crew, fast neutron cancer therapy, studies of electronics failure induced by cosmic ray neutrons and accelerator-driven incineration of nuclear waste and energy production technologies. In radiation treatment, the kerma (Kinetic energy release in matter) coefficient, which describes the average energy transferred from neutrons to charged particles, is widely used. The kerma coefficient can be calculated from microscopic nuclear data. Nuclear data above 20 MeV are rather scarce, and more complete nuclear data libraries are needed in order to improve the understanding of the processes occurring on a cellular level. About half the dose in human tissue due to fast neutrons comes from proton recoils in neutronproton (np) scattering, 10-15% from nuclear recoils due to elastic and inelastic neutron scattering and the remaining 35-40% from neutron-induced emission of light ions. Experimental data on elastic and inelastic neutron scattering at 96 MeV from C-12 and O-16 have been obtained recently at The Svedberg Laboratory in Uppsala, Sweden. These data are shown to be relevant for the determination of nuclear recoil kerma coefficients from elastic and inelastic neutron scattering at intermediate energies.
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| 3. |
- Mermod, P., et al.
(författare)
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Precision measurements of the np scattering differential cross section in the intermediate energy region
- 2007
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Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 126:1-4, s. 109-112
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Tidskriftsartikel (refereegranskat)abstract
- In fast neutron cancer therapy, similar to 50% of the cell damage is caused by recoil protons from neutron-proton (np) scattering. In the intermediate energy region, there is a need for unambiguous np scattering data with good precision in both the shape of the angular distribution and the absolute normalisation. The normalisation techniques have been reviewed for np scattering measurements as well as recent experimental results, particularly the data obtained at The Svedberg Laboratory at 96 and 162 MeV. In addition, to what extent systematic uncertainties in the np differential cross section might affect the determination of proton recoil kerma coefficients is investigated.
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| 5. |
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| 6. |
- Öhrn, Angelica, et al.
(författare)
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Elastic scattering of 96 MeV neutrons from iron, yttrium, and lead
- 2008
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 77:2, s. 024605-
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Tidskriftsartikel (refereegranskat)abstract
- Data on elastic scattering of 96 MeV neutrons from Fe-56, Y-89, and Pb-208 in the angular interval 10-70 degrees are reported. The previously published data on Pb-208 have been extended, as a new method has been developed to obtain more information from data, namely to increase the number of angular bins at the most forward angles. A study of the deviation of the zero-degree cross section from Wick's limit has been performed. It was shown that the data on Pb-208 are in agreement with Wick's limit while those on the lighter nuclei overshoot the limit significantly. The results are compared with modern optical model predictions, based on phenomenology and microscopic nuclear theory. The data on Fe-56, Y-89, and Pb-208 are in general in good agreement with the model predictions.
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| 7. |
- Öhrn, A., et al.
(författare)
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Measurements of Inelastic Neutron Scattering at 96 MeV from Carbon, Iron, Yttrium and Lead
- 2011
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Ingår i: Journal of the Korean Physical Society. - : Korean Physical Society. - 0374-4884 .- 1976-8524. ; 59:2, s. 1817-1820
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Tidskriftsartikel (refereegranskat)abstract
- Inelastic neutron scattering for (12)C, (58)Fe, (89)Y and (208)Pb have been measured at 96 MeV at the The Svedberg Laboratory in Uppsala and double-differential cross sections are reported. Data cover an excitation energy range of 0-45 MeV and the angular intervals are 28 - 58 degrees for (12)C, 26 - 65 degrees for (58)Fe and 26 - 52 degrees for (89)Y and (208)Pb. In this experiment, neutron detection is based on conversion to protons in an active scintillator converter. An analysis technique in which the neutron spectra have been obtained through a folding procedure using the response of the detector system has been used. The results are compared to and are in reasonable agreement with several model predictions and with inelastic neutron scattering data at 65 MeV from University of California, Davis, USA.
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| 8. |
- Österlund, Michael, et al.
(författare)
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Elastic neutron scattering studies at 96 MeV for transmutation
- 2007
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Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 126:1-4, s. 119-122
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Tidskriftsartikel (refereegranskat)abstract
- Elastic neutron scattering from (12)c, N-14, O-16, Si-28, (40) Ca, Fe-56, Y-89 and Ph-208 has been studiedl at 96 MeV in the10-70 degrees interval, using the SCANDAL (SCAttered Nucleon Detection AssembLy) facility. The results for C-12 and Pb-208 have recently been published, while the data on the other nuclei are under analysis. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. A novel method for normalisation of the absolute scale of the cross section has been used. The estimated normalisation uncertainty, 3%, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. Elastic neutron scattering is of utmost importance for a vast number of applications. Besides its fundamental importance as a laboratory for tests of isospin dependence in the nucleon-nucleon, and nucleon-nucleus, interaction, knowledge of the optical potentials derived from elastic scattering come into play in virtually every application where a detailed understanding of nuclear processes is important. Applications for these measurements are dose effects due to fast neutrons, including fast neutron therapy, as well as nuclear waste incineration and single event upsets in electronics. The results at light nuclei of medical relevance (C-12, N-14 and O-16) are presented separately. In the present contribution, results on the heavier nuclei are presented, among which several are of relevance to shielding of fast neutrons.
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