Fusion Reactors & Moon Helium: Is Helium a Better Option?

AI Thread Summary
Helium, particularly Helium-3, is considered for fusion reactors due to its aneutronic properties, which avoid producing radioactive waste. However, fusing Helium is more challenging than Hydrogen due to higher electric repulsion, and Hydrogen is more abundant and readily available. The extraction of Helium-3 from the Moon poses significant logistical challenges, which may outweigh the benefits of its use in fusion. While Helium-3 can be sourced on Earth as a by-product of tritium decay, its natural abundance is very low, making it less viable without significant economic incentives. Alternatives like Lithium-6 for fusion propulsion are also discussed, highlighting the complexities in choosing the best fuel for fusion reactors.
Engineering news on Phys.org
Aquamarine said:
Is helium a better alternative then the current proposed fuels for fusion reactors?

http://www.space.com/scienceastronomy/helium3_000630.html
http://www.asi.org/adb/02/09/he3-intro.html

Aquamarine,

Helium would be more difficult to fuse than Hydrogen - there's more
electric repulsion with Helium than with Hydrogen. We also have more
Hydrogen than Helium readily available.

The one item in favor of Helium, is that if one uses Helium-3 [ available
on the Moon ], then the fusion reaction is "aneutronic" - it doesn't produce
neutrons - so it doesn't make other materials radioactive.

However, radioactivity is not an insurmountable problem - it can be
readily dealt with. The problems associate with getting Helium-3 from
the Moon, and bringing it back will probably dwarf the problems with
radioactivity.

Dr. Gregory Greenman
Physicist
 
You know, nothing in either of the links Aquamarine gave tells us about the abundance (or difficulty of extracting) of He3 here on Earth (other than as a by-product of human activities). No doubt it's available here on Earth (otherwise, how would physicists have done experiments into its superfluid nature, for example?), and no doubt a minor component of the helium that's part of natural gas deposits. I suspect that if He3 were to become economically valuable, all kinds of entrepreneurs would find ways to supply the demand ... without having to go to the Moon to mine it!
 
Although the natural abundance of He-3 is very low (0.0137% in terrestrial sources), it can be obtained in relatively large amounts, as the product of the radioactive decay of tritium, which has been made for thermonuclear systems.

Of the tritium produced in the ten years following WWII (1945-1955), all of that, which has survived, has been through at least 4 half-lives, so more than 94% of it is now He-3. Of course, much of that may have already been used in experiments.
 
He3 is an isotope heavilly bombarded on the lunar surface from solar waves (rays) which are tritated (not referring to water). This component can be used for propellant production however, lithium (which is almost abundent beaneath earth) is a more greater option.

- thus Li 6 - D is applicable for direct fusion propulsion, only after fission - because of thermal laws (millions of degrees).
D can be made from regular water - 1 in 6000 atoms are exising Dueterium /D.
 
Hello, I'm currently trying to compare theoretical results with an MCNP simulation. I'm using two discrete sets of data, intensity (probability) and linear attenuation coefficient, both functions of energy, to produce an attenuated energy spectrum after x-rays have passed through a thin layer of lead. I've been running through the calculations and I'm getting a higher average attenuated energy (~74 keV) than initial average energy (~33 keV). My guess is I'm doing something wrong somewhere...

Similar threads

Back
Top