22nd Annual NASA Space Radiation Investigators' Workshop (2011)
7141.pdf
Comparison of Space Radiation Shielding Material Results for Solar Proton Exposures
B. B. Gersey1, R. T. Wilkins1,2, B. Atwell3, K. Rojdev4
1
NASA Center for Radiation Engineering and Science for Space Exploration;
2
Department of Electrical and Computer Engineering; 3The Boeing Company, Houston, TX 77059; 4NASA Johnson
Space Center, Houston, TX 77058.
High energy protons are a significant component of the solar and galactic cosmic radiation spectra. Experiments
were performed at the proton synchrotron at Loma Linda University Medical Center, Loma Linda, CA (2008) to test
the shielding efficiencies of standard and multifunctional materials with thicknesses of 1 to 25 g/cm2. The materials
tested included aluminum, high density polyethylene, and boron and lithium doped polyethylene composites.
Materials for study were chosen based on their potential for radiation shielding applications, as determined from
initial modeling calculations, along with their potentially useful structural properties. The shielding efficiency of
each material was determined by comparing the absorbed dose and dose equivalent measured with a tissue
equivalent proportional counter (TEPC) downstream of the shield under test. The NASA LaRC high energy particle
transport/dose code HZETRN 2005 was used to calculate the absorbed dose and dose equivalent expected from the
incident proton beam downstream of the shielding materials. The experimental and modeling results will be
presented and compared.
Key words: space radiation, radiation shielding, radiation countermeasures, microdosimetry, SPE exposure