IRA FLATOW, host:
This is SCIENCE FRIDAY from NPR News. I'm Ira Flatow.
Just east of San Francisco Bay, the world's most powerful laser sits in a quiet suburb just waiting to be switched on. This is a project that has been decades in the making, and this is a really big laser.
It was built with one purpose in mind, to blast, for just billionths of a second, a target the size of a pea filled with hydrogen with 500-trillion watts of power. The hope is to recreate the extreme pressures and temperatures that you find inside stars, like our sun, where hydrogen atoms fuse together to make helium and give off loads of energy in the nuclear fusion process.
But not all scientists are optimistic or even cautiously optimistic that the lab is capable of creating this star fusion on Earth. Every year, it seems, fusion energy is just 30 years away, and I remember visiting an experimental laser-fusion device called Shiva about 30 years ago, in 1978, at the same laboratory. That was dismantled a little bit later, and then it was upgraded to another one called Nova, and so on and so on, and these experiments have been going on for years.
So we're going to talk about this new effort today. Our number is 1-800-989-8255, 1-800-989-TALK, and as always, you can go to our Web site at sciencefriday.com, and you can Twitter us @scifri.
Let me introduce my guest. Ed Moses is the principal associate director at the National Ignition Facility and the Photon Science Directorate at the Lawrence Livermore National Lab in Livermore, California. Welcome to SCIENCE FRIDAY.
Dr. EDWARD MOSES (Principal Associate Director, National Ignition Facility; Photon Science Directorate, Lawrence Livermore National Laboratory): How are you doing, Ira? It's good to be here.
FLATOW: Thank you. I remember those old projects from years ago. What makes you think you're going to get to home base this time?
Dr. MOSES: Well, those old projects were actually all groundbreaking projects in both fusion and laser technology, and while there were some ideas that they could reach fusion at that time, basically there was a major study by the National Academy of Sciences in the early 1990s where it was decided that there was enough knowledge about the scale of a laser facility that had to be built in order to get fusion in the laboratory, and that was how the NIF facility or the National Ignition Facility, the laser you've been talking about, was sized.
And now it is built, and it is operational. So it's not ready to be operational, it's actually operating right now. It's meeting all the specifications it needs, as far as we know, to get fusion. We have the kind of targets we need, and we'll be doing experiments over the next year to 18 months to see how this all works out.
FLATOW: You actually have almost 200 laser beams, right, that converge on one little pea-sized pellet.
Dr. MOSES: Right. It's kind of an interesting thing. We have 192, to be exact. So it's quite a large building, but because photons, or the little particles of light that we're driving together, do not mind being very close together, in fact they'll get infinitesimally close together, you can create very high energy density, and when you do that, you can bring these targets, you know literally, from near-absolute zero in temperature up to hundreds of millions of degrees in billionths of a second.
And when you do that, you get conditions that exist like the conditions that exist in the center of the sun or other stars, and if that is true, which we think it will be, they should fuse together, and we'll have that e=mc2 energy. We'll turn mass into energy like Einstein told us, and we should have more energy out than we put in. That's kind of an interesting promise.
FLATOW: Past break-even point.
Dr. MOSES: Yes, past break-even, and this is scientific break-even, of course.
FLATOW: As a difference as compared to what?
Dr. MOSES: Okay, scientific break-even means we put - we get more energy out than the laser energy we put into the target, but it's not quite, in this case, the amount of get more energy out than we put into the plug that runs the laser. That'll be the next step.
FLATOW: And when do you think you'll achieve this scientific break-even point?
Dr. MOSES: Well, our goal is right now, and we're in the process of doing this, to start experiments this summer and fall and be ready to do implosion experiments - remember this is not an explosive process. It's an implosion process. We drive things together to be very high density. In fact, when it lights off, it'll be smaller than the diameter of your hair. Hopefully next summer, so a year from now.
FLATOW: And what do you have to do between now and then?
Dr. MOSES: Okay, well there's a couple of - as you said, there's a couple of physics issues, now that we have all the tools in place, that we're going to explore, and you know, one is when you put this much energy into this environment, it makes it, you know, very hot, like millions of degrees in literally the first two or three billionths of a second.
Now you have a lot of very hot matter, which is called the plasma, in the target, and that could start steering beams or things like that, and we have to work through those issues. That's why we have an ultraviolet laser that will pierce through that. And then once we do that, the next question is, the big step is, when you compress this target from the size of a pea, as you said, to the diameter of a hair, how does it all come together nicely, roundly, smoothly so that it will get the pressures and temperature conditions to get thermonuclear burn.
FLATOW: I think a lot of people are going to say if they're heating this thing up to hundreds of millions of degrees, then why aren't you melting the whole facility down?
Dr. MOSES: Well, because it's - first of all, because it's so small, right, that even though, you know, the temperature is extremely hot, the amount of energy in it compared to the facility is really relatively small. So there's no fear of actually doing any damage to anything.
And the other thing that's nice about fusion, it actually just burns out, right. So it doesn't - our goal is to get it to burn not for a millionth or a billionth, but a few trillionths of a second. Then the fuel is consumed, and it stops. So you don't have to worry about runaway or anything like that.
FLATOW: Let's talk about a theoretical nuclear fusion reactor. Would that, then, be a series of these little explosions, one after another, sort of on a conveyer belt, or how would you draw the energy off continuously like we would do in the fission reactor?
Dr. MOSES: Yeah, I think the way - the way I think about it is the way I think about, you know, an engine in a car, right. An engine in a car, it looks like it's continuous on one level, but we know it's just a bunch of cylinders and spark plugs going off, pop, pop, pop, pop, pop, you know, a few hundred to a few thousand revolutions per minute.
That's what we would do with the laser. What we'd do is we'd fire targets in literally sort of like on a blow gun, you know, these small little targets, as you said, the size of a pea, and we hit them with a laser when they're in the center of the target, and the energy would come out, and we would collect that energy and then finally turn it into electricity.
And the way you do that is kind of traditional. You know, you absorb the energy in some hot salts and run it over some water, make it, make steam, turn to turbine, turbine makes electricity, put it on the line, you plug in. So from where you're sitting, it'll look totally transparent as to how that energy was made, but when you go outside, no carbon, no pollution, no climate warming, none of those other issues that come with many other types of energy.
FLATOW: Is this totally paid for by government research?
Dr. MOSES: Yes, this is a U.S. government project. It's in the Department of Energy.
FLATOW: Assuming that this does - you're able to achieve ignition and go on to do scientific work with it, how much would you have to ramp it up to make…
Dr. MOSES: Well actually, this is what's very interesting about this facility. You know, we're going to be in a single-shot mode, which means we'll do a - you know, we can fire the laser with the targets every few hours, but what's great about this kind of fusion energy that even if you did it 10 times a second, or 600 rpm, every single shot is independent.
So we'll be ramping it up over the next couple years to learn how to make it more efficient and more energy capable, and when we do, we'll be able to then work simultaneously on these higher - what we call repetition-rate systems - so that you could get energy online.
FLATOW: So you're saying that we - I'll have to stop making that joke that fusion is always 30 years away next year.
Dr. MOSES: Well actually, you know, that has been the statement, I don't know if it's a joke or not, but that people do use that as a joke, that fusion is 30 years away no matter what year you ask, but here we are right now, hopefully in the next two, three years at the outside, hopefully we will have demonstrated that it has happened.
And I think when it does happen, it could be a very important time for us because, you know, when we look at ourselves as a country, as members of international society, we do need ways to get carbon-free energy, number one, and also, if you think about this, what are we using for fuel? We're using the hydrogen and water. There's a lot of it. You know, it has no carbon in it, it's not geopolitical.
If you can make this all work, it changes the way you think about a lot of things, and that's always been the goal of the fusion process. It is the power of the sun, right? We would build the miniature sun on Earth, very miniature, and we'd be running them at a high rep rate to make power to run our society in a very clean way, and hopefully world societies.
FLATOW: Could you also do experiments to recreate what goes on out in the universe, like supernova, things like that?
Dr. MOSES: Yeah, actually you can. I mean, you know, right now, astronomy is an observational science. What we do is look at our beautiful satellites, whether Earth-based or space-based, as things that happened, literally, you know, thousands of years ago or millions of years ago, even billions of years ago as we stare out at the cosmos.
What if you could take those conditions, very miniature versions (unintelligible) of course, and create them in the laboratory at the National Ignition Facility, and actually schedule them so you could have a star or a supernova or a Jovian supergiant planet, or these new super-terrestrials that are being found as we look for planets out there in the galaxy? What if you could do that right here? We think we can, and scientists from all over the world are proposing experiments to do these kind of - to create these kinds of conditions right here in this laboratory. It's very exciting.
CONAN: Let me ask you, while I've got about a minute left. What is your biggest hurdle yet to overcome now?
Dr. MOSES: Well, I think the biggest hurdle right now is, you know, just putting all of the equipment together, now that it's operational, in these experimental configurations and really getting good data out of it so that we can understand the phenomenology that we're looking at, react appropriately to it and do the experiments that we have to do in order to get, you know, gain, which is more energy out than we put in, which has been what we've been striving for, for the last 30 years.
FLATOW: There you go. Ed Moses, thank you for taking time to be with us today.
Dr. MOSES: Thank you so much.
FLATOW: Good luck to you. Ed Moses, principal associate director at the National Ignition Facility and the Photon Science Directorate at Lawrence Livermore. That's out there in Livermore, California.
We're going to take a break and come back and talk about nuclear fission, which powers our nuclear power plants. So what's the future of nuclear power? Does nuclear power have a place next to solar and wind? Why are folks who believe in green technology supporting nuclear power? We'll get into a debate and a discussion and your questions. Stay with us. We'll be right back.
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FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR News.
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