Talk:Helium

"Physics equation question

2D 3He --> 4He 1H or 2D + 3He --> 4He + 1H "Someone keeps anonymously removing the '+' signs" Whoever it is, please would you explain why. We will revert the edits until an explanation is provided as we cannot figure out if it is vandalism or not. Thanks. Charles F. Radley 15:03, 1 July 2007 (UTC)

current uses for He3

What are the current uses for He3, other than fussion power research? What potential markets open up if the price begins to fall?

Davew 11:48, 24 December 2006 (PST)

Application - Medical lung imaging

According to Wikipedia:

http://en.wikipedia.org/wiki/Helium_3

Medical lung imaging is an interesting new experimental application of He3.

Details:

http://cerncourier.com/main/article/41/8/14

Charles F. Radley 12:35, 7 January 2007 (PST)

He3 Fusion Works!

The opening statement is incorrect: "even though He3 fusion is not yet demonstrated". Gerald Kulcinski's group at the Fusion Technology Institute of the University of Wisconsin-Madison has had a working He3 fusion reactor operational for some time now on a non-governmental research budget. See the article: http://www.thespacereview.com/article/536/1 which describes his research program. Answers to many questions regarding He3 and mining it on the Moon can be found in Jack Schmitt's book: "Return to the Moon: Exploration, Enterprise, and Energy in the Human Settlement of Space", Harrison H. Schmitt, Praxis Publishing (Springer, New York, 2006), a very detailed analysis of the problems, costs, and benefits of setting up a lunar He3 mining colony. This work should form the core of the discussion of this article since there is no other major work on the topic available.75.41.119.150 12:33, 31 December 2006 (PST)

Greetings thanks for the link. I will correct the Lunarpedia article accordingly.

Yes I am well aware of the work of Schmitt and his colleagues at Wisconsin-Madison, although I had missed the part about the experimental reactor. We should note, however, that the reactor they have does not achieve break-even, that is it consumes more energy than it creates. They acknowledge that it will be at least 20 years before break-even of He3 can be demonstrated.

The fact also remains that De-Tr and De-De fusion are easier to achieve than He3 fusion, and we are nowhere near break even on the other fusion methods. For the past 40 year scientists have claimed that we are 10 to 20 years away from fusion break even. In other words, no measurable progress has been achieved, and there are no credible predictions of how long it will take. When Schmitt and his team claim that He3 is 20 years away, I would says that we could multiply that number by 5 or more.

Therefore, for all practical purposes, commercial fusion (of any kind, He3 or other) is vaporware. I discount it at a basis for lunar development in my lifetime. My focus is on more near term goals.

Well, yes, of course. But break-even was not the point in suggesting the above correction (for which thanks for the alteration). To have achieved He3 fusion at all was remarkable, given that Kulcinski's operating budget is from two private sources amounting to less than 6 figures, while on the other hand billions of government monies have been poured into the international tokamak reactor (ITER). A larger research budget and more personnel for Kulcinski's group would alter the projected time to break-even considerably. As for the De-Tr cycle, problems with that were also discussed in the Kulcinski interview cited above which make those processes less favorable. 75.41.119.150 15:01, 31 December 2006 (PST)

Direct Solar Heating

Has anyone done the calculations on the required diameter of a fresnel lens that could be effectively used to heat the regolith in the recovery of He3 and other volatiles?

Davew 12:38, 30 January 2007 (PST)

Hi Dave, I previously posted some numbers. It makes no difference whether it is a Fresnel lens versus a reflector, the diameter is the same. At large apertures, lenses have greater losses than mirrors, so reflectors are normally used. In Astronomy, for example the break point is generally around 25 cm aperture. There are very few refractors with diameters greater than 25 cm Charles F. Radley 13:15, 30 January 2007 (PST)

Tritium decay produces He3. Tritium is produced by bombarding an isotope of lithium with neutrons in a fission reactor. Why can't lithium be mined from regolith, bombarded, the tritium stored and the Helium3 slowly be drawn off? could there be any advantage of this over collecting the He3 from the regolith directly? And what about other gases produced by heating regolith? What use could they be of? T.Neo 10:28, 31 July 2008 (UTC)

Other volatiles produced can be found on the Volatiles article. - Jarogers2001 17:42, 31 July 2008 (UTC)

I see in the volatiles article that hydrogen is the most bundant volatile on the Moon. Is this in regoltih alone or mostly in ice at the poles? If so, is it available in the regolith to be viable for use as rocket fuel? T.Neo 13:04, 1 August 2008 (UTC)

Just the regolith alone. Harvesting regolithic hydrogen for use as rocket fuel is likely to be much less economical than using it to compensate for the small but gradual leakage of atmosphere during oxygen production as well as that from pressurized habitats. The ice at the poles is another question entirely. There is disagreement as to how that hydrogen should be utilized. Personally, I would prefer to keep it on the moon while shipping oxygen back to LEO for a propellant depot. Probably cheaper to ship hydrogen to LEO than to ship it to the moon to make up for a future shortage. - Jarogers2001 19:30, 1 August 2008 (UTC)