Maren: 2019 is an exciting year for many reasons, not the least of which being that it’s the
150th anniversary of the Periodic Table!!!
Back in 1869, that old chestnut of a year, Russian chemist Dmitrii Ivanovich Mendeleev
decided he need a little more organization in his scientific life.
No more pen and paper lists, no higgledy-piggledy piles of stuff—the fundamental elements
of life needed to be put in order in a way that makes SENSE, goshdarnit.
We’ve put together an introductory primer on the periodic table, how it works, what
information it tells us, and why it’s such a nice, neat way of organizing the world’s
elements over here—and, spoiler alert, there are some discussions of possible redesigns.
But the focus of this video?
Is something so insane it doesn’t even sound real.
Elements are substances that cannot be broken down any further, each is its own type of
atom, with different numbers of neutrons, protons and electrons.
They cannot get simpler, they’re what we call the primary constituents of matter—if
you try and break them apart, you just get subatomic particles, like the protons and
neutrons of the nucleus.
And here at the Lab?
We make new ones.
We make new….stuff!
But how?
Intro Music
Dawn: So, creating an element is really just taking two other elements and merging them
together, fusing them into one so we can add up all their protons, because it is the proton
number that determines what the element will be.
So for instance, if we use 116 as an example, we start with something that has 20 protons,
which can be calcium, and then we can take another material that has 96 protons, which
is curium, and if we can fuse those together we actually get an atom of element 116.
Well, the nuclei have a lot of positive charge so they don't want to merge naturally, so
we have to overcome that repulsive force, very similar to two magnets that would have
the plus sides aiming they want to break apart, the same thing with the two nuclei.
So we use what's called a cyclotron and it's a particle accelerator where we take that
calcium and we accelerate it through two large magnets which are shaped both like D's, and
we can alternate voltage across there and that makes the calcium go faster and faster
in a circular orbit until we finally get it to close to the speed of light.
At that point the calcium can be extracted from the cyclotron and we actually just blast
it into our target of curium and the energy of that accelerated calcium helps overcome
that repulsion and they can actually fuse together and become a new element
Element 116 or Livermorium.
Maren: That’s right!
Element 116 is named after the Lab—Livermorium!
And all of this is super duper cool but like…why?
Why do we do it?
What does making new elements tell us about the way the world works that we didn’t know
before?
Dawn: The new elements really help us understand the physics of how the nucleus comes together.
As we get out to these higher numbers things that don't exist in nature, it's really pushing
the boundaries of these physics models, and it’s really helping us understand really
the fundamental physics of how matter comes together.
These things are likely made in a very explosive environment like the Big Bang or potentially
even a supernova, so these things are existing we just don't know about it cause they’re
so short lived, so all this kind of data feeds into our overall understanding of the formation
of the universe and matter in the universe, how things come together.
Maren: Understanding how the universe came together does sound pretty exciting.
But making an element is also a lonnnnnnng process.
Many, many months of beam time go into creating huge data sets that then need to be analyzed
by not only our team but also our collaborators all over the world.
If everybody sees the same decay chains, or a specific series of radioactive decay products
that result as an element changes, then all the scientists start to think that maybe there’s
something there.
But even then, everyone is cautious and stays skeptical as they move toward publication,
just to make sure we don’t get too caught up in the excitement—I mean if you’re
gonna announce a new element, you gotta make sure you’re right.
Dawn: That’s where our detector comes in.
The detector is made of silicon strips, they’re semi-conductors, and the new element comes
in and implants itself into one of these silicon strips, and all of these things are radioactive,
so they’re undergoing decay and they’re emitting particles.
It’s the energy of that particle is embedded in the silicon detector and we can electronically
see what energy the particle had and also what time it was emitted.
Then we use a computer to sort through that data and what we’re looking for are a series
of decay particles that have the right energy, they’re correlated in time, they’re in
the same spot in that detector array, and when we see that we know that those are all
part of the same element and that’s how we verify that we made a new element.
Maren: So we collaborate internationally for a lot of these projects.
It’s a pretty world-changing thing, discovering a new element, so it’s only fitting that
those who work on it are from all over said world.
In particular, we collaborate with scientific teams in Russia and Germany on elemental exploration.
Dawn: The group in Russia is really the one that has made these experiments possible their
accelerator, the U400 Cyclotron, it's very well characterized it a blowtorch for these
calcium beams meaning the intensity is just incredible, so without their expertise and
their instrument I am not sure we would be talking about this today at least from a Livermore
point of view.
Maren: Specifically at Livermore we’re now working on building chemical platforms that
would help us understand more about the way elements like 112 and 114 behave.
Some very clever aqueous chemistry coming out of our forensic science center is working
to create molecules that would be able to hold these unstable elements in place a little
bit longer—elements this volatile, like the ones we create, disappear almost instantly,
many of them only last on the order of milliseconds.
So, to get a longer look at them just a little bit longer we’re hoping to get it into a
system where we sweep it across these molecules we’re building and see if it's binding inside
these molecules, how it’s binding compared to its neighbors and periodic table, and hopefully
learn more about its properties.
It’s a little bit like these high atomic number elements are really rare wild animals
that we know relatively little about, and the molecules we’re working on making would
act a little bit like a cage so we could trap the element and run some tests.
But what’s next in the big picture?
I mean, does the Periodic Table keep expanding?
What does the future of the periodic table look like?
Dawn: There's physics answer, which is how far can you push a nucleus and how heavy can
you make it and still define it as a nucleus?
And I've seen different answers for that, I've seen people say in the low one thirties
might be the limit for that.
But then there's the actual physicality of doing that experiment.
How do we detect something with a now sub millisecond halflife?
How do we transport something fast enough?
This is where some new technology would have to come into play.
There have been searches for 119 and 120.
They have not been successful yet, but it's pointing us in the direction of where people
need to go to do that.
It might be a few more years
or many more years, it's hard to say, but I think at some point we will see some more
elements on the periodic table, it would be a question of what is the technology advance
that needs to happen for us to push beyond that.
Maren: In the meantime, these awesome elemental creations are helping us push the boundaries
of our understanding of everything from quantum physics, on the ‘inside-the-atom’ scale,
to the conditions inside supernovas.
And I for one can’t wait to see what we smash together next.
If you liked this video, subscribe to our channel for more ‘Inside the Lab’ videos
coming soon, and don’t forget to watch our Periodic Table primer here.
Follow us on social media for more exciting elements content, and as always thanks for
watching.
See ya next time!