Depending on your environment and the sensitivities of what you're shielding, you might need one or the other, and possibly both.
Disclaimer: I'm not a nuclear physicist. I learned this while researching for a hard-sci-fi novel I'm working on.
Maybe get the kids to look into using Magnetorquers to get some spin on and half shield with this product .. and you now have a platform for directional gamma ray detection | mapping.
( Gamma counts coming from "over there" will decrease whenever "over there" is masked by the partial shielding )
There are other apps, but that one springs to mind.
But it is only 15% by volume... So to the casual observer, this material is mostly plastic.
So I think the casual observer would notice that. But also means with thar price per KG.
Pure tungsten on the other hand is very good and can even shield beta particles
it should be heavier than lead; lead is only 11.3 g/cc, tungsten is 19.3, 75% tungsten would be 14.5, but then the other 25% is petg with sp.gr. ≈ 1 so you should actually get a density of 14.7
but i struggle to imagine cases where using tungsten is a more cost-effective option than using lead and making the object 9% bigger? they cite 'various medical applications' but tungsten isn't exactly ideal for permanent body contact either
oh actually they say it's 75% tungsten by mass, not volume, so it's only 4 g/cc, and so its attenuation (at 140keV) is only 18% of lead's (by volume)
copper might be an alternative that is less toxic than lead and less expensive than tungsten
That said, no metal dust is very nice. Solid lead might be safer than tungsten powder. Maybe you could make an iodinated polymer or use a barium cement.
- Osmium: [US$13000/kg][8], 22.65 g/cc, or possibly iridium at more than twice that price
- Tungsten: [US$30/kg][9], 19.3 g/cc
- Tungsten carbide? Not sure what it costs but its density is 15.6 g/cc.
- Lead scrap: 95¢/kg, 11.3 g/cc
- Steel scrap: [21¢/kg][10], 7.9 g/cc
- Magnetite: [10¢/kg][11] [or so][12], 5.2 g/cc
- Quartz (as construction sand): 3¢/kg, 2.6 g/cc
- Water: [.06¢/kg][22] or so, 1 g/cc
[8]: https://www.metalary.com/osmium-price/ [9]: https://www.metalary.com/tungsten-price/ [10]: https://www.usgs.gov/centers/nmic/iron-and-steel-scrap-stati... [11]: https://www.usgs.gov/centers/nmic/iron-ore-statistics-and-in... [12]: https://stockhead.com.au/resources/barry-fitzgerald-why-magn... [22]: http://www.scientificamerican.com/article/israel-proves-the-...
this is my approximation of the pareto frontier; that is, each of the items on the list is conjectured to be cheaper than everything that's denser than it is, and denser than everything that's cheaper. corrections are welcome
i was thinking baryta (46¢/kg, 4.48 g/cc), mercury, litharge, minium, cinnabar, cupric oxide (US$3.90/kg, 6.315 g/cc), zinc oxide (US$29/kg, 5.6 g/cc), and manganese dioxide (5.026 g/cc) might be interesting in this context too
i hadn't thought of your suggestion of galena (just cinnabar) and generally i'm skeptical of metal sulfides because of their tendency to produce hydrogen sulfide; i don't think that's an issue with those two. litharge, minium, and mercury are a lot more worrisome toxicologically
i don't have solid pricing information for mercury, litharge, minium, cinnabar, or galena, and i'd be interested
tungsten is probably more chemically inert for medical purposes than a lot of these
I was thinking weights to fit specific items. Model railway wagons, for example, need to be weighted and balanced to operate smoothly, but you have significant size constraints. I threw a bunch of tungsten weights inside a small locomotive to give it extra tractive effort.
You'd likely do better just machining it out of steel (5g/cm³, and much cheaper)
Err, they make it sound like ordinary lead is the best choice? The article's point is that additive manufacturing is a workaround for tungsten's difficult material working properties. But: lead foil, you can simply bend it with your hands, into any shape you want. And apparently it's much thinner.
But the tungsten costs many times more, and is also much harder unlike lead which is soft and easily worked, which is why radiation shielding is still overwhelmingly made of lead. In applications where its toxicity is a problem, it's used encapsulated inside another inert material.
The other high-melting metals near it in the periodic table all fall down on one or more of those properties. Osmium, for instance, is rather expensive, mined in only very small quantities, and reacts with air to form highly-toxic osmium tetroxide.
> In the staining of the plasma membrane, osmium(VIII) oxide binds phospholipid head regions, thus creating contrast with the neighbouring protoplasm (cytoplasm). Additionally, osmium(VIII) oxide is also used for fixing biological samples in conjunction with HgCl2. Its rapid killing abilities are used to quickly kill live specimens such as protozoa. OsO4 stabilizes many proteins by transforming them into gels without destroying structural features. Tissue proteins that are stabilized by OsO4 are not coagulated by alcohols during dehydration.
> OsO4 will irreversibly stain the human cornea, which can lead to blindness. The permissible exposure limit for osmium(VIII) oxide (8 hour time-weighted average) is 2 µg/m3. Osmium(VIII) oxide can penetrate plastics and food packaging, and therefore must be stored in glass under refrigeration.
