[PDF] Quasifree Proton Neutron And Proton Proton Scattering At 140 Mev eBook

Author : Ralph Wallace
Publisher :
Page : 24 pages
File Size : 36,1 MB
Release : 1950
Category : Neutron-proton interactions
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Neutron-proton scattering with 90 Mev neutrons has been investigated by others,1,2 using a proportional counter technique and also using a cloud chamber. They measured the scattering cross section for neutrons for center of mass angles from 36° to 180°. The present experiment was performed with nuclear emulsions in order to permit the detection of protons down to about 1.5 Mev, and to avoid systematic errors that might be present in the case of other methods of detection. The results agree with those of Hadley, et al., within probable error, and the cross section curve exhibits beyond 36° the same general trend as the curve measured by hadle, et al. The measurements confirm the fact that there is probably not complete symmetry of the n-p cross section curve about 90° in the center of the mass system.

Author : Matthias Holl
Publisher :
Page : 0 pages
File Size : 23,4 MB
Release : 2019
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The quasi-free scattering reactions 11C(p, 2p) and 10,11,12C(p, pn) have been studied in inverse kinematics at beam energies of 300-400 MeV/u at the R3B-LAND setup. The outgoing proton-proton and protonneutron pairs were detected in coincidence with the reaction fragments in kinematically complete measurements. The efficiency to detect these pairs has been obtained from GEANT4 simulations which were tested using the 12C(p, 2p) and 12C(p, pn) reactions. Experimental cross sections and momentum distributions have been obtained and compared to DWIA calculations based on eikonal theory. The new results reported here are combined with previously published cross sections for quasi-free scattering from oxygen and nitrogen isotopes and together they enable a systematic study of the reduction of singleparticle strength compared to predictions of the shell model over a wide neutron-to-proton asymmetry range. The combined reduction factors show a weak or no dependence on isospin asymmetry, in contrast to the strong dependency reported in nucleon-removal reactions induced by nuclear targets at lower energies. However, the reduction factors for (p, 2p) are found to be 'significantly smaller than for (p, pn) reactions for all investigated nuclei.

Author :
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Page : 24 pages
File Size : 30,10 MB
Release : 1949
Category : Neutrons
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An experimental measurement of the angular distribution of protons scattered by neutrons in the neutron beam of the 184-inch Berkeley cyclotron has been made with a Wilson cloud chamber with magnetic field. The results show that the scattering is not isotropic in the center of mass system and that it is not symmetric about 90 degrees. The peak of protons in the forward direction indicates that a certain amount of charge exchange is taking place between the neutron and proton.