Simulation of Cosmic Ray Interactions with Materials
Date
2011-03
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
New York State College of Ceramics at Alfred University. Kazuo Inamori School of Engineering.
Abstract
A representative group of target materials were simulated and irradiated within
the physics framework of two Monte Carlo particle transport codes to determine the
general effects of energetic space radiation on common solid materials. The target
materials consisted of low-density polyethylene, polyethylene-based composite filled
with glass particles, and solid slabs of beryllium, aluminum, and tungsten metals. The
simulated composites were irradiated by solar protons within the MCNPX software to
determine the secondary gamma and neutron radiation generated in and transmitted
through potential lightweight shielding materials. The pure polyethylene and elemental
targets were bombarded by protons and 12C nuclei within FLUKA to determine the extent
of charged meson production, energy deposition, and generation of stable or unstable
nuclear fragments within the target. The polyethylene-based composites of this work
enable a maximum of 8% weight reductions, so have potential value as lightweight
shielding materials, but any incorporated elements with Z significantly larger than one
cause detrimental neutron and gamma radiation to be produced by the incident proton
events. Charged meson production peaks at a density of about 10-4 per incident primary
at the center of the particle beam, and a maximum of roughly 10-4 GeV/cm3 of energy is
deposited in all targets per primary proton. The polyethyelene targets appear to
backscatter significant particle radiation, and also yield only 6 unstable fragments within,
compared to 11 stable fragments. Unstable fragments decay by electron capture, which
does not result in a significant dose from the emitted neutrinos. The effects of other
radiation-matter interactions such as scattering events and Bremsstrahlung are also
discussed.
Description
Advisory committee members: Alexis Clare, Doreen Edwards, William Carlson.Dissertation completed in partial fulfillment of the requirements for the degree of Doctorate of Philosophy in Glass Science at the Kazuo Inamori School of Engineering, New York State College of Ceramics at Alfred University
Type
Thesis