New experiment finds weird atomic nucleus with dumbbell shape (Patreon)

 [This is a transcript with links to references.]

Image an atomic nucleus. What does it look like? Is it round, like, a ball? Yeah, that’s what I used to think they look like. But this group of researchers from China has found one that has the shape of a dumbbell.

Atomic nuclei are made up of protons and neutrons, and they carry the big bulk of the mass of atoms. The number of protons determines the atomic number and with that, the type of chemical element. Atomic nuclei are known to be able to vibrate and to slightly deform, and some are more perfectly round than others. But this dumbbell nuclei is extraordinary indeed.

In the new study they looked at a type of Beryllium atom. That’s a fairly small atom with atomic number four. The most common type of Beryllium is Beryllium 9. For the new study they looked at Beryllium 10, which has one neutron more in the nucleus. Beryllium-10 is slightly radioactive. It decays into Boron with a half-life of about one and a half million years.

To image the beryllium-10 atoms, the researchers used the Radioactive Isotope Beam Factory from the RIKEN Center in Japan. With that, they accelerated a beam of beryllium-10 to half the speed of light and shot it into a 2-millimeter-thick target of solid hydrogen. Then they measured into which directions the decay products flew away, and from this they reconstructed the shape of the Beryillium-10 nucleus.

They found that the structure of the beryllium-10 nucleus resembles that of two helium-4 atoms which make up a dumbbell-shaped core. And then there are two neutrons rotating between them, perpendicular to the core’s axis.

While structures like this are common at the atomic level, where different atoms combine to molecules, they haven’t been confirmed before on the level of nuclei. I know this sounds like a rather obscure super-specialized experimental finding, but I find this incredibly interesting because it means that nuclear structure is much more complex than we thought. Imagine we could synthesize different atomic nuclei the way we can synthesize molecules. This could give rise to a completely new type of chemistry and materials that we presently can’t even dream of. Who knows, maybe one day someone will even produce comfortable bras.