Nuclear cascade calculations of the Goldberger type have been performed using the MANIAC electronic computer. A three-dimensional relativistic treatment was used. The target nuclei were Al 27 , Cu 64 , Ru 100 , Ce 140 , Bi 209 , and U 238 . Incident protons and neutrons with energies between 82 and 365 Mev have been studied, but meson production was neglected in this energy range. Cascades initiated by about 1000 incident particles were followed in each case.The results have been compared with those of previous calculations of this type, as well as with experimental photographic-plate data and counter measurements reflecting the cascade stage of high-energy nuclear reactions. The agreement with experimental data is usually good.Tables and graphs are presented showing the frequency of occurrence of various residual nuclei, and data on the residual nuclear excitation energy after the cascade is over. A few comparisons with radiochemical data indicate over-all agreement with the general spallation pattern of copper with 340-Mev protons and good agreement with the Ni 64 (^>,w)Cu 64 reaction over the energy range 100-400 Mev. However, the calculated results for the Cu 66 (p,pn) Cu 64 reaction are low by almost a factor of two, although the energy dependence is approximately correct.
The nuclear cascade calculations described in the preceding paper have been extended to incident energies up to 1.8 Bev with the inclusion of pion production, scattering, and absorption processes. Again the MANIAC electronic computer was used. Several incident proton energies between 450 Mev and 1.8 Bev have been investigated, with Al 27 , Cu 64 , Ru 100 , Ce 140 , Bi 209 , and U 238 as target nuclei. Cascades initiated by pions of several energies up to 1500 Mev incident on Ru 100 have also been studied. The elementary cross sections used and the assumptions made about details of the inelastic nucleon-nucleon and pion-nucleon processes are presented. The results of the calculation are summarized in tables and graphs giving data on transparencies, on numbers, energy spectra, and angular distributions of emitted cascade nucleons and pions, and on frequencies of occurrence and excitation energies of residual nuclei. The computed number distributions, energy spectra, and angular distributions of emitted particles are compared with the results of several emulsion experiments with incident protons and negative pions. The agreement is generally satisfactory, but certain discrepancies are found, for example regarding spectra and angular distributions of emitted pions; some of these discrepancies are discussed in terms of details of the model used. The calculation predicts quite well the over-all yield distribution of spallation products of copper produced by 2-Bev protons; however, as at lower energies, the calculated cross sections for (p,pn) reactions are too low by factors of two or three. NUCLEAR MODEL AND INPUT INFORMATIONT HE nuclear cascade calculations described in the preceding paper 1 have been extended to the interval 0.4-1.8 Bev in incident nucleon energy. Pion production (single or double), pion scattering and charge exchange, and pion absorption have been included with varying degrees of completeness and accuracy. The angular distributions in nucleon-nucleon scattering, pion-nucleon scattering and charge exchange have also been taken into account. Cascades induced by incident pions have also been investigated. This appears to be the first extensive attempt to carry such calculations into the energy region in which pion effects are important. However, after the completion of the present computation, NikoPskii et al. 2 have published some results of a Monte Carlo cascade calculation involving 162-Mev ir~ mesons incident on emulsion nuclei.As in I, the calculations were performed relativistically in three-dimensional geometry by means of the MANIAC electronic computer at Los Alamos. The nuclear characteristics chosen for the target nuclei were the same as in I, with the radius parameter ro always taken as 1.3X10 -13 cm. Neutrons, protons, and the three types of pions were distinguished throughout. The mass of all the pions was taken as one-seventh of the nucleon mass. No nuclear or electrostatic potential was included for the pions, and Coulomb scattering was neglected for all particles.The behavior of each ...
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