What is the laser interaction with uranium vapor?

Answer 1

You are speaking to atomic vapor laser isotope separation of 235U from 238U, and it's a "high tech" solution to the problem of enriching uranium. The process of atomic vapor laser isotope separation goes by the acronym AVLIS. Let's do a short review, then hammer the answer onto WikiAnswers. Ready? Buckle up. It is 235U that is fissile, but it is 238U that comprises over 99% of all uranium. Bummer. But how do you separate uranium from uranium? Good question, and that's the problem. We've used the difference in the mass of the different isotopes to do it mechanically. If we combine uranium with fluorine to make a gas and then spin it, the lighter 235U floride can be differentially "spun out" and can be separated with careful manipulation of a "gate" control. This is what was done at Oak Ridge, and continues to happen around the world. That's why you hear all that talk about centrifuges when the international nuclear investigators are poking around in someone's backyard. Enriched uranium us used as fuel and as weapons material. Fast forward to now. What if there was a way to selectively ionize one of the isotopes? What if we could do that with a laser? What if we took a bunch of uranium and streamed it down an evacuated tube and applied a magnetic field across the path of travel of the uranium? And then precisely tuned a (dye) laser to do the ionization? What if we could get it to deliver just the right amount of energy to just the 235U atoms to kick an electron up and away leaving a positively charged ion? And the ions suddenly felt the effects of the magnetic field they were moving in? And then the ions were forced to veer off the path because a charged particle moving in a magnetic field experiences acceleration? And that left the rest of the uranium, the 238U, to fly on down the tube unaffected? Then picked off the deflected 235U ions and allowed them to recombine with an electron to become neutral? And collected them as refined 235U? Would that work? Yup. And that's what we do. Got a link below to the Wikipedia article on this refining process.