Mercury activation? the strange case of Hg199m

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Richard Hull
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Mercury activation? the strange case of Hg199m

Post by Richard Hull »

I was looking over the Table of the isotopes and going down the line of elements. Mercury looked rather unappealing as a lot of naturals would only create a lot of other naturals like the nice Hg 199 with a cross section of 2000 looked sweet but just makes natural Hg200...Bummer.

I notice the strange Hg 199m with a workable half life of 43min As an IT it would be a shell electron hustler and maybe a weak gamma emitter. I noticed the large Gamma percentages of 158keV and 375keV.
Hmmm. How th' heck is this made?

It seems there are a bunch of ways with meV alphas and meV deuterons, but also neutron bombardment of Hg199 which gives off a neutron while making Hg199m, and Hg200 which gives off 2 neutrons while making Hg199m!!!

A neutron multiplier setup and it makes Hg199m as well! The cross section of Hg200 is <50?? A little forethought might reduce this weird "less than 50 guess".... Neutron bombardment of all the isotopes especially the relationship of increasing Hg200 while at the same time dealing out 2 neutrons from one in a moderator, we dare you to give a hard and fast cross section for it!
Basically, the two naturals 199 and 200 make up 40% of the mass of mercury! Cool!
Too good to be true? Well I hope to try this after HEAS as I am running around like a mad Turk right now!! Should one of you fully instrumented folks seek to test this, share your experience. I have every thing I need to do this except only about 500kn/s. Some of you folks have 10e7 or better.
It may just turn out that the net reactions combined to make Hg199m are rare. Maybe, maybe not.
Activation die casting. Remember, "Research is what we're doing when we don't know what we are doing"....until we've done it.
Suggestion: make a 2X2X.25-inch plexiglass box pour in the mercury, permanently seal the box by gluing on a lid. You have a thin enough mercury source of large area for you gamma spec after exposure.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Jim Kovalchick
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Re: Mercury activation? the strange case of Hg199m

Post by Jim Kovalchick »

A 3 mm layer of mercury will capture 99% of the thermal neutrons it sees.
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Rich Feldman
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Re: Mercury activation? the strange case of Hg199m

Post by Rich Feldman »

How about over-filling a traditional mercury-maze puzzle? I have these in three different shapes.
Mercury-Maze-Quicksilver-Vintage-Puzzle.jpg
Mercury-Maze-Quicksilver-Vintage-Puzzle.jpg (33.08 KiB) Viewed 2392 times
.

The reactions Richard mentions must happen a lot at Oak Ridge's Spallation Neutron Source,
where tons of mercury are used to _produce_ neutrons at a flux exceeded only by fission reactors.
SNS2.jpg
All models are wrong; some models are useful. -- George Box
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Jim Kovalchick
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Re: Mercury activation? the strange case of Hg199m

Post by Jim Kovalchick »

Jon R did some previous work with measuring neutron capture prompt gammas from mercury. I think that is a much easier phenomenon to detect using a fusor.
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