Saturday, December 16, 2006

Helium-3, the next super fuel

For NASA's planned manned lunar base camp by 2024, the most challenging aspect is the fuel reserves to maintain continual operations on the lunar terrain.
Solar fuel cells aren't enough for such a large scale operation. They have to find something readily available to satisfy the fuel requirements. Fortunately, scientists have discovered one such resource, available aplenty on the moon.

Meet Helium-3, the future. Unlike Earth, the moon has large reserves of Helium-3 which is a light, non-radioactive isotope of helium and highlty sought-after for use in nuclear fusion research.
Some experts estimate there a millions of tons in lunar soil -- and that a single Space-Shuttle load would power the entire United States for a year.

Helium-3 undergoes the following aneutronic fusion reaction, among others, although this is the one most promising for power generation:

D + 3He → 4He (3.7 MeV) + p (14.7 MeV)

The appeal of helium-3 fusion stems from the nature of its reaction products. Most proposed fusion processes for power generation produce energetic neutrons which render reactor components radioactive with their bombardment, and power generation must occur through thermal means. In contrast, helium-3 itself is non-radioactive. The lone high-energy proton produced can be contained using electric and magnetic fields, which results in direct electricity generation.

The future does look bright but experts say commercial-sized fusion reactors are at least 50 years away.

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