A strong, lightweight metal foam created by a North Carolina State University researcher absorbs the energy of high-impact collisions and effectively blocks X-rays, gamma rays, and neutron radiation. The device offers new shielding possibilities for use in CT scanners.
“High-Z steel-steel,” made up largely of stainless steel and a small amount of tungsten, is the most effective composite metal foam against all three forms of radiation. The structure of the high-Z foam was modified, however, so that the composite foam that included tungsten was not denser than metal foam made entirely of stainless steel.
The researchers found that the high-Z foam was comparable to bulk materials at blocking high-energy gamma rays, but was much better than bulk materials – even bulk steel – at blocking low-energy gamma rays. Similarly, the high-Z foam outperformed other materials at blocking neutron radiation. The high-Z foam performed better than most materials at blocking X-rays, but was not quite as effective as lead.
