Heavy-Ion Interaction Models for Radiation Transport

<p>This dissertation is concerned with finding the values for the nuclear cross sections used in the Boltzmann equation for space radiation transport and dose estimates. An extraordinary number of cross sections are required because of the large number of ion types and their extensive energy range, The Lippmann-Schwinger equation is numerically solved in momentum space for a first order optical potential (free space case) and calculations are made for the total and absorption cross sections for nudeus-nucleus scattering. Absorption cross sections are also calculated using a medium modified firstorder optical potential in the Lippmann-Schwinger equation and are compared with experimental values. Results are presented for the absorption cross sections for ⁴He-Nucleus and ¹²C-Nucleus scattering systems and are compared with experimental values below 100 A MeV. The use of the in-medium nucleonnucleon cross sections is found to result in a significant reduction of the free space absorption cross sections, in agreement with experiment. We have also reformulated the Glaubermodel of heavy-ion fragmentation to treat the cluster abrasion of alpha particles from a-cluster nuclei such as ¹²C, ¹⁶0 , ²⁰Ne, ²⁴Mg, ²⁸Si, ³⁶Ar, and ⁴⁰Ca. Comparison of the calculated values is made with recent experimental data and good agreement is found. The energy dependence and the target mass dependence of cluster knockout cross sections for the 160 projectile are discussed. The inclusion of clusters knockouts is shown to significantly modify transport properties of space radiations.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date.available

1995

Author dc:creator

• Dubey, Rajendra R.

Contributors dc:contributor

• Govind S. Khandelwal
• John H. Heinbockel
• J. Wallace Van Orden

• Boltzmann equation
• Lippmann Schwinger equation
• Nuclear

Statement dc:rights

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Repository record dc:identifier

https://digitalcommons.odu.edu/physics_etds/102

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:physics_etds-1102