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June 29, 2007

Boron nanotubes provide radiation shielding and more

Boron nanotubes can provide strong, light weight, cost effective radiation shielding for space and fusion reactors


Compared to CNTs, boron nanotubes have some better properties such as high chemical stability, high resistance to oxidation at high temperatures and are a stable wide band-gap semiconductor. Because of these properties, they can be used for applications at high temperatures or in corrosive environments such as batteries, fuel cells, super capacitors, high-speed machines as solid lubricant."

Space radiation is qualitatively different from the radiation humans encounter on Earth. Once astronauts leave the Earth's protective magnetic field and atmosphere, they become exposed to ionizing radiation in the form of charged atomic particles traveling at close to the speed of light. Highly charged, high-energy particles known as HZE particles pose the greatest risk to humans in space. A long-term exposure to this radiation can lead to DNA damage and cancer. One of the shielding materials under study is boron 10. Scientists have known about the ability of boron 10 to capture neutrons since the 1930s and use it as a radiation shield in geiger counters as well as a shielding layer in nuclear reactors.

1 comments:

M. Simon said...

I have been looking into Borons.

A very handy atom indeed.

However, Boron 10 captures neutrons and emits gammas. So you have to shield against the emitted gammas. Let me add that to capture neutrons they must first be thermalized. Water makes a good moderator.

One advantage is that B10 emits isotropically. So that helps some.
Let me add that carbon is a good moderator, However, the price of nanotubes is way too high.