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- Auce, Agris, 1966-
(författare)
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Reaction Cross Section Measurements for p,d,3He and 4He at Intermediate Energies
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Reaction cross sections were measured for protons at 65.5 MeV, for deuterons at 37.8, 65.5, 97.4 MeV, for 3He at 96.4, 137.8, 167.3 MeV, and for 4He at 69.6, 117.2, 163.9 and 192.4 MeV. Targets were 9Be, 12C, 16O, 28Si, 40,48Ca, 58,60Ni, 112,116,118,120,124Sn and 208Pb. 48Ca and 118Sn targets were used only for some of the measurements. Rest of the targets have been measured for all energies and projectiles but 4He at 69.6 MeV where reaction cross sections were measured for 9Be, 12C, 16O, 28Si, 40Ca targets. A modification of a standard attenuation technique was used. Details of the experimental design are presented.Experimental uncertainties were 2-3% for p, 3% for d and 3-10% for 3,4He. A strong forward peaking of the reaction products was observed for 3,4He. Therefore the standard reaction cross section measurement technique was not applicable for these projectiles. The forward peaking is also responsible for the increase of experimental uncertainties for these projectiles. The forward peaking of the reaction products is not known for other projectiles and has also not been observed with 3,4He at different - both higher and lower - energies. Possible explanations for this phenomenon are discussed.Optical model calculations of the reaction cross sections are in good agreement with the measured values.The measurements were performed with beams from the Gustav Werner cyclotron at the The Svedberg Laboratory, Uppsala.
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| 3. |
- Carlson, R. F., et al.
(författare)
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A method for measuring light ion reaction cross-sections
- 2005
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 547:2-3, s. 541-554
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Tidskriftsartikel (refereegranskat)abstract
- An experimental procedure for measuring reaction cross-sections of light ions in the energy range 20 50 MeV/nucleon, using a modified attenuation technique, is described. The detection method incorporates a forward detector that simultaneously measures the reaction cross-sections for five different sizes of the solid angle in steps from 99.1% to 99.8% of the total solid angle. The final reaction cross-section values are obtained by extrapolation to the full solid angle.
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| 4. |
- Ingemarsson, Anders, et al.
(författare)
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Energy dependence of proton-nucleus reaction cross sections
- 2005
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Ingår i: Physical Review: C. ; 72:6, s. 064615-
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Tidskriftsartikel (refereegranskat)abstract
- Reaction cross section data for proton-nucleus scattering up to 1 GeV have been analyzed in a black-disc model. Simple phenomenological relations are derived, which makes it possible to predict the energy depence of proton-nucleus reaction cross sections. The relations require only the total cross sections in nucleon-nucleon scattering and the matter densities of the proton and target nucleus.
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| 10. |
- Lantz, Mattias, 1971-
(författare)
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Investigations of Reaction Cross Sections for Protons and 3He
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The reaction cross section gives the probability that a particle will undergo a nonelastic process when passing through a nuclear medium. Therefore reaction cross section data are of importance both for theoretical studies and for applications in such diverse fields as medicine, biology, astrophysics and accelerator-driven transmutation of nuclear waste.There exist many data sets with angular distributions of elastic scattering, but very few measurements of the complementary reaction cross section have been performed. The measurement is in principle simple but has in practice proved to be very difficult to perform, and the relatively limited amount of experimental data displays some serious inconsistencies.Results from measurements of reaction cross sections are presented for:• 3He on 9Be, 12C, 16O, 28Si, 40Ca, 58,60Ni, 112,116,118,120,124Sn and 208Pb at 96, 138 and 167 MeV• protons on 12C, 40Ca, 90Zr and 208Pb at six energies in the energy range 80-180 MeV, and on58Ni at 81 MeV.Experimental uncertainties were 3-9% for 3He and 1.5-8% for protons.The apparatus and the experimental method used for the measurements of reaction cross sections, using a modified attenuation technique, is described. The detection method enables simultaneous measurements of reaction cross sections for five different sizes of the solid angles in steps from 99.0 to 99.8% of the total solid angle. The final results are obtained by extrapolation to the full solid angle.Experimental results are compared with predictions from optical model calculations using phenomenological global optical potentials.Phenomenological parametrizations of reaction cross sections for scattering of projectiles on targets are presented. The parametrizations show that reaction cross sections are very sensitive to matter distributions at very large radii of both the projectile and the target. For protons the derived relations makes it possible to predict the reaction cross sections on targets for which no experimental data exist.
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| 11. |
- Strevens, Helena, et al.
(författare)
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Author's Reply.
- 2004
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Ingår i: BJOG: An International Journal of Obstetrics & Gynaecology. - : Wiley. - 1471-0528 .- 1470-0328. ; 111:2, s. 193-195
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Tidskriftsartikel (refereegranskat)abstract
- Abstract is not available. Author's Reply to correspondence about article "Glomerular endotheliosis in normal pregnancy and pre-eclampsia"
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