david007
hello,

i'd like to buy a small amount of the element thorium to give to someone as a gift for his 90th birthday. ideally i'd like to buy 90g, but i suppose any amount is fine. I've found a couple of sites that sell thorium [american elements, nova elements], but they seem to be out of stock. i was hoping someone on these forums could share a link or two to other places where i might find it.

note - not looking for items that may contain thorium, like old lamp mantles. i'd like the actual element. something like the little vials displayed on this page would be perfect.

thanks.

Staff Emeritus
There is no such thing as Thorium-90.

Pure thorium is not cheap. Think $50,000/90 g and it will take a lttle chemistry to get the pure element. Last edited: Algr and berkeman Mentor i'd like to buy a small amount of the element thorium to give to someone as a gift for his 90th birthday. Maybe give him the whole Periodic Table instead -- much more fun at parties! https://www.physicsforums.com/threads/where-to-buy-thorium-90.1015140/ Klystron, pinball1970, Astronuc and 1 other person Staff Emeritus Science Advisor Where to buy thorium-90 ? hello, i'd like to buy a small amount of the element thorium to give to someone as a gift for his 90th birthday. ideally i'd like to buy 90g, but i suppose any amount is fine. I've found a couple of sites that sell thorium [american elements, nova elements], but they seem to be out of stock. i was hoping someone on these forums could share a link or two to other places where i might find it. note - not looking for items that may contain thorium, like old lamp mantles. i'd like the actual element. something like the little vials displayed on this page would be perfect. thanks. As Vanadium 50 indicated, we do not call thorium thorium-90. Usually the number in hyphenated designation is the atomic mass, A, of a particular isotope, e.g., Th-232 (14 billion year half-life), not the atomic number Z of the element, which for thorium Z=90. American Elements is probably the one I would recommend, but possible Reade. https://www.reade.com/products/thorium-metal-th  horium Th Wire diameter is 0.22 mm with lengths from 0.05 m - 1 m 99.5% It would be best if encased in a sealed glass tube. One might consider 90 mg or μg. Last edited: pinball1970 Science Advisor Why not find a stainless steel alloy with some magnesium? Mg+Cr+Fe+Ni = 12+24+26+28 = 90 Klystron, diogenesNY, anorlunda and 3 others david007 thanks to all for your helpful replies. and apologies for my ignorance re- nomenclature. heh...$50k is a little out of my price bracket. O_O

i did try american elements, as well as nanoshel, nova elements, and metallium. as you've pointed out, this apparently innocuous metal once used in lamps and welders isn't cheap, strangely enough ; the best quote i got so far was $1575 for 100g of thorium oxide. there are some other suggestions in your replies that give me some interesting ideas to pursue. many thanks! Last edited: berkeman and pinball1970 Staff Emeritus Science Advisor Education Advisor mildly radioactive Not so mildly. You definitely want it behind glass and far away. Hornbein Not so mildly. You definitely want it behind glass and far away. The gift that keeps on giving. How about a mixture of yttrium and zirconium with atomic weight 90? I bet such a gift has been given never before in the history of Man. Staff Emeritus Science Advisor i did try american elements, as well as nanoshel, nova elements, and metallium. as you've pointed out, this apparently innocuous metal once used in lamps and welders isn't cheap, strangely enough ; the best quote i got so far was$1575 for 100g of thorium oxide.
Thorium is used as an alloying element. In lamps and tungsten welding rods, it is used in the oxide (ThO2) form, as in thoriated-tungsten (~1-2% thoria).
The American Welding Society (AWS) has a position paper on thoriated-tungsten electrodes, and they recommend alternatives using ceria, lanthia, yttria or zirconia.
http://files.aws.org/technical/facts/FACT-27.pdf

Some people swear by thoriated-tungsten electrodes
https://www.thefabricator.com/thewe...-i-still-use-2-percent-thoriated-red-tungsten

I've watched them in use, and I would agree with the welder in the Fabricator article. Thoria has the highest melting point (~3370 +/- 20 °C) of all oxides.

Thorium has special uses as a source material for production of 233U, which is why there are certain restriction on the amount of material. While it is mildly radioactive, some of the daughter products are more radioactive (e.g., 228Ra, 228Ac, 224Ra, 220Rn. . .).

Thoria (and decay daughters) can become airborne from alpha decay (atoms may recoil from the surface), hence the strong recommendation to have thorium in a sealed glass container.

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Tom.G and DaveE
Staff Emeritus
How about a mixture of yttrium and zirconium with atomic weight 90? I bet such a gift has been given never before in the history of Man.
Zr-Y alloys have been made, but usually not as a gift. Usually, there are more elements involved.

Algr
Zirconium 90 is stable, and is the most common isotope of zirconium, making up 51.45% of all zirconium.

Staff Emeritus
Zirconium 90 is stable, and is the most common isotope of zirconium, making up 51.45% of all zirconium.
and if one purchases pure Zr, then one will get the natural combination of 0.5145 90Zr, 0.1122 91Zr, 0.1715 92Zr, 0.1738 94Zr and a wee bit of 0.0028 96Zr, and probably some Hf with it. A pure isotope of any element is quite expensive, except perhaps for those with one stable isotope, but one should expect a small fraction of impurities carried over from processing.

Staff Emeritus
Some people swear by thoriated-tungsten electrodes
One weld of the LZ experiment cryostat was done with thoriated rods.. They know which one because they can see it in data.

making up 51.45% of all zirconium.
Typically isotopically pure materials start at $3000/g and go up from there. 90g will not be cheap. Algr Typically isotopically pure materials start at$3000/g and go up from there. 90g will not be cheap.
So 90 mg /.5145 = 174 mg of regular zirconium. That way 90 mg of it will be zirconium-90. If there are other impurities, (eg. Cubic zirconia ZrO2) adjust the quantity accordingly.

Staff Emeritus
Yes, but the OP said "not looking for items that may contain thorium". So an isotopic mixture that contains Zr-90 doesn't meet the requirements.

Staff Emeritus
One weld of the LZ experiment cryostat was done with thoriated rods.. They know which one because they can see it in data.
Yes, I saw that.
The 232The levels, as measured by the ICP-MS system, resulted in 3.20±0.16 ppb of Th, in comparison to 0.069±0.007 ppb measured for the TIMET HN3469 stock.
That's already fairly low, but does not meet the need for ultralow background requirement for LZ and similar experiments.
Additionally, it was found that the standard lanthanated tungsten electrodes used do contain a small amount of thorium which, in the welding process, gets into the weld at the level of 0.7ppb.

Most applications with which I'm familiar do not require such low background, and can tolerate ppb levels of 232Th or W in a weld. On the other hand, we practical, I advocate pulsed-magnetic welding (PMW), or what some call 'magnetic force welding' (MFW).

Algr
Yes, but the OP said "not looking for items that may contain thorium". So an isotopic mixture that contains Zr-90 doesn't meet the requirements.
He's making a gift, not a nuke.

...right?

Mentor
He's making a gift, not a nuke.

...right?
LOL. If I make it to 90 y/o, I would much appreciate the (not inexpensive) gift of the Lexan periodic table. I would not appreaciate a vial of gray sand. Just sayin'...

Klystron
Staff Emeritus
a vial of gray sand

"I got a rock" - Charlie Brown

All the sources I have looked at have been in six figures for 90 g. It's also not clear to me how to ship it. I know FedEx will do (or at least has done) this, but it is not cheap. Then again, neither is the Thorium.

Staff Emeritus