Producing lithium-6 deuteride

  1. A particle accelerator is necessary to produce this. where can i get a design or blueprint?
     
  2. jcsd
  3. Lithium-6 has a 7.6% abundance in natural lithium. deuterium has a 0.015% abundance in water.
     
  4. so how do you produce lithium-6 deutirde using an accelerator
     
  5. Astronuc

    Staff: Mentor

    One would not use an accelerator.

    To obtain lithium enriched in Li-6, one would use a mass spectrometer or laser enrichment system. These can be expensive, and laser enrichment is controlled technology. So it's best to find a chemical supplier.

    LiH is produced by exposing lithium metal to hydrogen gas. I do not know the exact values since I have not manufactured this material, this source indicates - "Lithium hydride is obtained directly in an ampoule by hydrogenation of lithium at a temperature of the order of 920 K and a constant hydrogen pressure of 1 MPa."
    http://www.springerlink.com/content/g3220v44k5263368/

    These are hazardous conditions and one may require permits to do this. It's not something that is done in one's home.
     
  6. Since lithium-6 and lithium-7 atomic masses differ by more than 15%, it should not be particularly difficult or expensive to separate lithium-6 using standard gas centrifuge methods. And, since lithium has melting point of less than 200 C, it can be done in a home workshop. The biggest challenge is that lithium is highly flammable and so the whole process should ideally be done in the vacuum.

    Deuterium can be produced in the same manner. The initial concentration is much lower, but the 50% difference in atomic masses and the fact that you can work with cold equipment (heavy water is liquid at room temp) makes separation technologically easy, if time- and energy-consuming.

    I know for a fact that you can buy heavy water online and it's relatively inexpensive, and it's much easier than to try to make it yourself. You can probably buy enriched lithium-6, too. It's not a controlled chemical, as far as I know.

    If you insist on using an accelerator, the easiest way to go is to use an electron accelerator and a lithium-7 target:

    [tex]Li^7 + e^- \rightarrow He^7 \rightarrow He^6 \rightarrow Li^6[/tex]

    I'm not sure how high an energy you need to make helium-7, on the order of MeV's most likely, which means that most accessible types of accelerators (fusor, CRT electron gun) are out, you'll need to build a cyclotron ... there was a thread on this forum a while back that discussed building a homemade cyclotron.

    You will then electrolyze resulting heavy water and heat lithium-6 and deuterium gas in a hermetically sealed container to 600-700 C, where they will react to produce lithium-6 deuteride.
     
    Last edited: Jun 15, 2009
  7. Someone making fusion bombs with Li-6-D? What are you going to replace the fission trigger with? You'll need U238 for the x-ray reflector to trigger fusion via implosion.
     
  8. The US (and other nations too, probably, such as the UK and Russia) used to produce enriched Li-6 for Teller-Ulam secondaries, but largely stopped after it was understood that it's really not necessary to use enriched lithium for this purpose.

    It's not produced with an accelerator, it's produced via isotope exchange between LiOH and Li amalgam, kind of like the Girdler Sulfide process for deuterium enrichment.

    Once you've got lithium and hydrogen with appropriate isotopic enrichment, reacting them together to produce LiD is just like reacting them to produce any stable LiH.
     
  9. Vanadium 50

    Vanadium 50 17,443
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    That's a weak process. Expect it to take a very, very long time.
     
  10. He-6 and He-7 would be extremely unstable, and would expel neutrons to become He-4 very quickly.
     
  11. Vanadium 50

    Vanadium 50 17,443
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    No, He-7 decays to He-6 by neutron emission, and He-6 beta decays to Li-6. That's all correct. But using an electron to turn a proton into a neutron will take a very long time.
     
  12. Gordon

    Since you specify 6Li2D, rather than lihium-six and deuterium, I assume you are interested in a fusion bomb.


    I don't know about today, but I recall that several decades ago the US Govmnt took all the Li-six from newly mined lithium. Lithium deuteride doesn't degrade, to my knowledge, and with the cessation of nuclear weapons testing, I would guess that not much lithium-six is required by the weapons labs.

    You are correct that deuterium gas and heavy water can be purchased, legally, in the USofA: people doing electrostatic-confined-fusion experiments use deuterium gas in their "fusors", either directly or by electrolysis of heavy water.


    Neil
     

  13. Wouldn't this reaction further decay the Li-6 by the very nature of the constant bombardment of electrons?

    Just out of curiosity, how much time is a long time? Say... for one gram of Li-7?
     
  14. Vanadium 50

    Vanadium 50 17,443
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    Think "lifetime of the universe"
     
  15. mheslep

    mheslep 3,383
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    Deuterium is available from retail suppliers and is inexpensive. I would think that other low atomic number isotopes could also be separated relatively inexpensively(?), that is, compared to the price of the element in natural, mixed isotope form.
     
  16. You could bombard beryllium with protons to make lithium 6 but my guess is the cross section is low and the energy required high.
     
  17. Was hoping to find a more current thread but here goes. I am interested in Lithium 6 deuteride and in fact if it is legal to possess or manufacture. The reason is that I saw a utube video of a guy who used it in tanks in conjunction with HHO to operate a gas engine. It was said that it requires a paricle excelerator to make it. Would that be true? Anything you could share would be helpful. Thanks, TM
     
  18. I know the video to which you refer. Lithium 6 would make a great storage medium for hydrogen, but that stuff will cost you an arm and a leg. Converting Lithium 7 to Lithium 6 would take an enormous amount of energy, so much for so long that it would be cheaper just to buy it.

    I don't want to say it isn't possible, but I wouldn't believe everything you see from that site.

    P.S. The video of that particle accelerator is actually just a big Van de Graff generator.
     
  19. Thanks for the quick reply. The video I saw was a gentlemen by the name of Bob Lazar with a Corvette outfitted with four tanks. I am not sure it showed an accelerator. Do you know if the Lithium 6 is even legal to possess?
    It is a very intriguing combination for use at an alternate fuel.
     
  20. mfb

    Staff: Mentor

    Is there any particular advantage of Li-6 over Li-7 as hydrogen storage, apart from the ~15% lower mass?
    I would not expect any issues here. Sure, it is a part of hydrogen bombs, but it is not sufficient to do anything dangerous - you still need a fission bomb.
     
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