This interview originally aired on In the Moment on SDPB Radio.
The Majorana Demonstrator has been working hard and listening closely from deep beneath the Black Hills. The data it's collected on a tiny particle could hold answers to some big questions: Why are we here? Why is the universe full of something rather than nothing?
Cabot-Ann Christofferson is a chemist, researcher and professor at South Dakota Mines. She's worked on the Majorana Demonstrator experiment since its beginning.
She breaks down what the experiment was, what it found and why the miniscule neutrino could be a big deal.
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Lori Walsh:
You're listening to In the Moment on South Dakota Public Broadcasting. I'm Lori Walsh.
Well, deep in the Black Hills, the Majorana Demonstrator has been quietly listening for the past few years. It's listening to the universe to see if it could answer a very big question, why are we here?
The success of this experiment has brought us one step closer to understanding an important imbalance in the universe.
Cabot Ann Christofferson is a chemist and researcher at South Dakota Mines working on the demonstrator since the beginning and is with us now in SDPB'S Black Hills Surgical Hospital Studio in Rapid City.
Cabot Ann, welcome back to In the Moment. Thanks for being here.
Cabot Ann Christofferson:
Thank you so much for having me.
Lori Walsh:
Let's go back to maybe 2010 or so. When you're standing in this space, tell us about that.
Cabot Ann Christofferson:
Well, it's fantastic that we've had such good coverage over the past almost 13 years of this experiment that's been going on. The point of being here is that last week we had a very big publicity that was really to show the broad physics program that the Majorana Demonstrator completed at SURF, our final result, the paper was just released, and the new directions that we're able to do with this science that it is at SURF.
I just want to take a moment to thank our host lab, Sanford Underground Research Facility, that this experiment was conducted in. We were funded from the Eunice Department of Energy, the Office of Science, National Science Foundation of Coast Oak Ridge National Lab, Los Alamo National Lab.
It takes a lot of people, a lot of resources to get to where we are today. So I'm very happy to be here.
Lori Walsh:
So this is a global competition in ways too. So the administration has to be on point. The funding has to be solid. The science has to be sound. What does the success of this exhibit and the potential scalability of it mean to you?
Cabot Ann Christofferson:
Well, what we were able to do is we were able to show that we could fine tune specific parts of this experiment through its uniqueness. With that, we combined with a European experiment that had some other capabilities. And going forward, we then scale up to a next larger experiment that has more of a possibility of looking at this rare decay process we were searching for.
Then the next phase is an even larger experiment. So you think that maybe this is not resources well spent, but if you think about it, this is basic research and as you scale, you discover more, you invent more. We have a great amount of benefit that we get out of all of these technologies that are developed for these types of experiments, plus training the next generation of scientists, especially here.
Lori Walsh:
Let's talk about a couple of those things. I want to start, before we get to the scientists and the South Dakota students, undergrads, postdocs, everybody.
Let's go back to that ultra pure copper. When you talk about the technology that needs to happen, how important is that process and what you learned about creating that ultra pure copper going to do in the future in other applications or in this application?
Cabot Ann Christofferson:
That's one of our key things that we take forward into the next experiments. Let me just give you a little step. We use enriched Germanium-76, which has to be ultra pure, but you can't just take a material and put it in a normal container and see what's going to happen. We took all of these materials fabricated in-house or through special controls and we assembled it underground, so eliminating that possibility of noise or interference from the surface.
And then as you said, this ultra clean copper was one of the components that eliminated all of this background noise that could create an overshadow of this very, very tiny, minuscule energy point that we are trying to listen for that will help us understand how matter behaves. So those clean materials, clean techniques, these inventions of new types of detectors and low noise electronics that other avenues will benefit from, that's what was developed for this experiment going forward.
Lori Walsh:
For listeners who are a little unfamiliar to this, catch them up with this imbalance in the universe. What is the big question that you're trying to get closer to answering?
Cabot Ann Christofferson:
Yeah. The big question is if we think about when the universe was created, matter and antimatter were in equal amount. So as they come together, you should just have an annihilation with a release of energy and that's all that remains. But what we see is that there's matter that remains in the universe and we don't quite understand where that imbalance comes from. So, understanding how matter is interacting is an answer of why the universe is here.
So what we look at is we look at these processes of the neutrino that may answer this question about this tiny minuscule with very little matter, no charge that is emitted from reactions. We see neutrinos coming from the sun every day. They're released as hydrogen fuses to form helium. We see it coming off nuclear reactors. There's neutrinos coming out of you because you're radioactive. Out of a banana.
These small tiny particles, we have to understand how it is that they may be the key of understanding this creation of matter from energy. So what we did is we took a unique isotope, or this Germanium, and we're able to look at these atoms and to see if we can observe this decay process to understand that behavior of the neutrino, if it could be both matter and antimatter. Both those things yet show us why there's still matter in the universe. So even that's a lot to take in.
Lori Walsh:
It is. And over the years, I think South Dakotans, through the science communication that you've done on this show and on other shows, has helped all of us understand this better. But let's go back to those students, those students who got to be working with science from all over the world, scientists from all over the world to be part of this process. How significant has that been for the legacy of this Demonstrator?
Cabot Ann Christofferson:
Well, this has been fantastic because you've had this opportunity of School of Mines and other South Dakota students coming and learning about this. They see other scientists, whether they're Ph.D., postdocs or scientists at labs, at universities. You get that exposure of in the lab working on these types of experiments and understanding that big picture, which really is just training them for whatever they do next. It doesn't necessarily mean that they have to go further into this type of work, but any exposure of basic science is going to benefit these students.
This is a physics experiment with many, many physicists. Being the chemist of still being able to bring in a wide variety of students from the School of Mines regardless of what their major was. I mean, we've had biology, mechanical engineers, chemical engineers, chemists, physicists that have come. They get this exposure and they see all how science and engineering interlinks, how you benefit from those collaborations to build an experiment. And I couldn't have done it without them. I mean, so being at the School of Mines, I get a wealth of students that are qualified to come and work underground and learn, and then go off and be the next generation of scientists that'll do these types of projects in the future.
Lori Walsh:
Real quickly, are you working on the next generation of this experiment? Are we going to continue?
Cabot Ann Christofferson:
I am. I do. Yeah. I have a big role and great news. SURF has a part to play in this too. Experiment happened at SURF, and we do have a next generation of what is happening down there. We modified the Majorana Demonstrator into a new decay process we can talk about in just a second.
But going forward, we have this ultra clean chemistry lab. We grow the electro formed copper underground, and this is just something that benefits SURF going forward. Even if the next experiment is not there, there's still a part contributing to this experiment with the chemistry of these ultra pure materials that need to be in the fabrication of these next generation experiments.
Lori Walsh:
Yeah. Well, we're going to have you back on. I want to make time for Dr. Lori Anderson with Mines next. More science conversation up next. But Cabot Ann Christofferson, congratulations. Thank you.
Cabot Ann Christofferson:
Thank you.
Lori Walsh:
And I very much look forward to our next time.
Cabot Ann Christofferson:
Wonderful. Thank you so much.
