It Takes Two to tango

Dr. Ligia Diana Pinto de Almeida Amorim

Do you recognize that music?

It is from my favorite Tango scene, from a movie that I love. If you don’t know it. Try to imagine it. Picture two great actors dancing beautifully together and using all of their energy to tell us an extraordinary story. And think, what if one of them was out of energy? Or tired? Maybe because of practicing tango on zoom for too long… Then the whole scene won't work.

Because it takes 2 to tango.

In physics, we do many experiments with a tool called a collider. That also needs two actors. You can think of each as a bunch of tiny particles. And they also have to be full of energy. So that they can collide and create a massive explosion, from where we also get lots of stories. In this case they are, for example, about the origin of our universe or how the building blocks of matter interact with each other.

But, there is a problem with colliders. For them to be able to give all that energy to particles. They end up becoming really large, sometimes larger than a single country. And so quite expensive and hard for scientists to access.

It is my goal to solve that problem. Here at Berkeley Lab, in the BELLA Center, we are building a compact accelerator technology. It uses very powerful lasers and the state of matter called plasmas. Which is a gas that reacts strongly to the lasers and transfers its energy to the particles very efficiently.

And we already showed that we can use it to give huge amounts of energy to a type of particles called electrons.

So we have our first actor ready to tango.

The second we need is made of particles called positrons. Here is our big challenge. Where our technology gives energy and keeps very focused the electrons, it does the opposite to positrons. And so it blows them away. So how are we going to get positrons ready to collide and tell us all the stories about the origin of the universe?

I wish to answer that question using computer simulations. In the Accelerator division’s Modeling Program and as part of the WarpX exascale project, I am developing two codes. One, to discover how we can create those positrons here in the lab. And the other to study in detail all the interactions between the lasers, plasmas, electrons and positrons.

And if I am. No, no, when I am successful, I will show you how we can get the two to tango.