Thank you so much st1d!! I was the original poster and I was getting totally lost with all the chemical technicalities. Your laymen’s explaination made it much easier for me to conceptualize what goes on. Thanks!!!
They lied, twitch. Tritium is an alpha source. The trick is to get the neutrons to be emitted at just the right time. That is the secret part.
Oak Ridge used gasseous diffusion and cyclotron-style isotope separation. Gaseous diffusion took it most of the way, but they used the calutrons to finish the job.
Miguelon, the patents for creating one (What ‘one’ refers to is not going to be mentioned) are all in a US Patent Library, for example, the one at my college, UCSD.
You should read them then you can see how much work they require.
That’s all I can say otherwise the mods would chew me out 
KeithB:
How can tritium be an alpha source? Alpha particles are atomic mass 4, tritium is mass 3 (hence the name.)
So much of this type of stuff can be solved by a quick trip to http://www.webelements.com - for example:
Isotope Mass (AMU) Half Life Decay mode
[sup]3[/sup]H 3.01604927 12.32 y Beta- to [sup]3[/sup]He
Chief Wahoo:
Nah - he was just building a reactor.
Oops, mea culpa, douglips.
But it still ain’t a neutron source! I assumed it was an alpha source since they use it for the backlight in watches. I assumed they would have a relatively safe alpha emitter rather than a more energetic beta emitter.
Thanks douglips, that was driving me crazy!
Tritium is a very low energy beta emitter, so it doesn’t require much shiedling at all for use in watches, exit signs, etc. I think the beta energy is so low that standard ion chambers won’t detect the presence of tritium–if you’re working with it you need special tritium detectors.
Also, alpha decays are typically much more energetic than beta or gamma decays (~20MeV vs. ~1MeV). It’s just that alphas are more easily shielded because they are massive, charged particles.
Miguelon,
I know you wanted people here to answer and not send you to the library, but for you question and the level of understanding you seem to have, I have to reccommend “The Making of the Atomic Bomb” by Richard Rhodes (I think). While parts of the book are rather boring and he sometimes editorializes a bit much regarding weapons of war, it is the best history of physics in the first half of the 20th century that I have read.
Thanks Mental Guy
Strange thing about these messages about these bomb things is not only are they very dangerous (much more dangerous than memorizing an eye chart which is one subject that Chronos has locked) & illegal but Chronos hasn’t said anything about this.
Maybe he doesn’t read this far down?
Maybe he realizes that such little practical information has been given here that can facilitate the actual construction of a nuclear weapon, and that even if such information was provided it would be extremely difficult to accomplish?
This is not like posting how to make a Chlorox bomb, or the best types of nails to epoxy to your pipe bomb. This is quite a bit more theoretical, and a Hell of a lot less doable.
Different degrees, my friend.