Friday, October 17, 2014

Fusion Power, Mirrors, and a Rambling Lemming

(From Eric Schulzinger, Lockheed Martin; via Aviation Week & Space Technology; used w/o permission.)
("The CFR test team, led by Thomas McGuire (left), is focusing on plasma containment following successful magnetized ion confinement experiments."
(Aviation Week & Space Technology))

"Skunk Works Reveals Compact Fusion Reactor Details"
Guy Norris, Aviation Week & Space Technology (October 15, 2014)

"Lockheed Martin aims to develop compact reactor prototype in five years, production unit in 10

"Hidden away in the secret depths of the Skunk Works, a Lockheed Martin research team has been working quietly on a nuclear energy concept they believe has the potential to meet, if not eventually decrease, the world’s insatiable demand for power.

"Dubbed the compact fusion reactor (CFR), the device is conceptually safer, cleaner and more powerful than much larger, current nuclear systems that rely on fission, the process of splitting atoms to release energy. Crucially, by being 'compact,' Lockheed believes its scalable concept will also be small and practical enough for applications ranging from interplanetary spacecraft and commercial ships to city power stations. It may even revive the concept of large, nuclear-powered aircraft that virtually never require refueling—ideas of which were largely abandoned more than 50 years ago because of the dangers and complexities involved with nuclear fission reactors.

"Yet the idea of nuclear fusion, in which atoms combine into more stable forms and release excess energy in the process, is not new. Ever since the 1920s, when it was postulated that fusion powers the stars, scientists have struggled to develop a truly practical means of harnessing this form of energy. Other research institutions, laboratories and companies around the world are also pursuing ideas for fusion power, but none have gone beyond the experimental stage. With just such a 'Holy Grail' breakthrough seemingly within its grasp, and to help achieve a potentially paradigm-shifting development in global energy, Lockheed has made public its project with the aim of attracting partners, resources and additional researchers...."

The Lemming started reading about fusion reactors about fifty years ago. At the time, humans said they'd have working fusion power stations in about fifty years. Looks like they'll be about ten years late: not bad, under the circumstances.

Warning! Rambling Lemming Reminiscing

About 94 years back, humans started working out what makes stars like their sun so hot: hydrogen nuclei fusing into helium, releasing energy.

A little later, they discovered that atoms release energy when their nuclei break apart, too: only not as much energy, and it generally won't happen unless you've got a very big nucleus.

Oddly enough, humans developed fission reactors long before coaxing hydrogen nuclei into fusing. Their early reactors were notoriously temperamental.

The trick wasn't to keep the fission reaction going: it was to stop it before it destroyed the reactor. That, and a global war that happened around the same time, may explain why the first 'practical' nuclear device was a bomb. Not, in the Lemming's opinion, a fact that's likely to help humans feel good about nuclear power: and that's not quite another topic.

Roughly 50 years back, humans invented the tokamak, a gadget that generates a doughnut-shaped magnetic field. Deuterium and tritium plasma, held in that field, would fuse into helium: releasing energy.

That's the idea, anyway. One of the problems with a tokamak is that fusion works best under extreme pressure — like in a star's core — and a tokamak starts leaking plasma at fairly low pressure. Still, tokamak reactors looked like the best bet for practical fusion reactors.

Another — it's not so much a problem as an issue — is that the physics involved in a tokamak mean that the things have to be big.

A 35-nation team is building the International Thermonuclear Experimental Reactor (ITER). When they're done, they'll have the world's biggest experimental tokamak nuclear fusion reactor. It'll be at the Cadarache research center in southern France.

They're planning to start experiments with it in 2020. Actually, it's next to the Cadarache research center. ITER will be big: 19.4 meters, 64 feet, across by 11.3 meters, 37 feet, high. That photo is of a much smaller tokamak, MIT's Alcator C-Mod.

They Do It With Mirrors: Magnetic Mirrors

Humans have been using magnetic mirrors for some time: mostly for research. In the 1960s, someone got the idea of using magnetic mirrors to hold plasma in a fusion reactor. That's what the Skunk Works team is doing.

Instead of trying to hold plasma in a doughnut-shaped volume, they're using magnetic mirrors to make a vaguely hourglass-shaped volume of plasma. One of the advantages of this shape is that as the plasma tries to expand: the 'bottle' gets stronger.

Lockheed's Skunk Works: Five Prototypes, Then the Production Model

(From Lockheed Martin, via Aviation Week & Space Technology, used w/o permission.)
("Neutrons released from plasma (colored purple) will transfer heat through reactor walls to power turbines."
(Aviation Week & Space Technology ))

"...The team acknowledges that the project is in its earliest stages, and many key challenges remain before a viable prototype can be built. However, McGuire expects swift progress. The Skunk Works mind-set and 'the pace that people work at here is ridiculously fast,' he says. 'We would like to get to a prototype in five generations. If we can meet our plan of doing a design-build-test generation every year, that will put us at about five years, and we've already shown we can do that in the lab.' The prototype would demonstrate ignition conditions and the ability to run for upward of 10 sec. in a steady state after the injectors, which will be used to ignite the plasma, are turned off. 'So it wouldn’t be at full power, like a working concept reactor, but basically just showing that all the physics works,' McGuire says.

"An initial production version could follow five years after that. 'That will be a much bigger effort,' he says, suggesting that transition to full-scale manufacturing will necessarily involve materials and heat-transfer specialists as well as gas-turbine makers..."
(Guy Norris, Aviation Week & Space Technology)

The Skunk Works has been around since the 1940s. Someone at Lockheed wondered if maybe engineers might get projects done faster, if they didn't spend most of their time filling out forms: requesting forms they needed for their semi-weekly reports.

Basically, the Sunk Works is run by engineers who get exact specs on what they're expected to produce: and are the sort of folks who keep working at a project. (August 31, 2009)

With any other outfit, the Lemming might think they were overly optimistic. When the Skunk Works says they'll have a production model in a decade: the Lemming's inclined to think they're serious.

The Lemming won't be surprised if tightly-wound humans get conniptions in late 2025 or so, when the first commercial fusion reactors hit the market, and that is another topic.

One Million Years of Singed Fingers

Humans started using fire about 1,000,000 years back. Since then, they're learned to cook without killing themselves, incinerated their cities at irregular intervals, and developed less flammable buildings. (April 9, 2012; A Catholic Citizen in America (April 27, 2014))

The lesson here, in the Lemming's opinion, isn't that fire is bad: it's that fire, string, or any technology can be dangerous.

Humans are clever critters, though. They've managed to use fire, lightning rods, and fission reactors, with only the occasional disaster. The Lemming figures that they'll learn to deal with fusion reactors, too.

On the other hand, some humans can be — surprisingly daft.

Back in 1946, some of them learned why "tickling the dragon's tail" is a bad idea: survivors did learn quite a bit about what extreme radiation levels do to humans, though.

As the Lemming said, any technology can be dangerous. There will be so much energy flowing through a working fusion power plant that 'leaks' could be hazardous.

Sure, eventually humans would run out of seawater: but that'd take a long time. Decades. Centuries. Maybe more. Earth is a very wet place.

Long before there's a 'seawater shortage,' it's the Lemming's guess that humans will have replaced fusion reactors with something else. They're clever that way: and a good thing, too, or they'd have long since run out of flint.

Maybe they'll have worked the bugs out of antimatter reactors, learned how to extract useful levels of energy from phenomena like the Casimir effect, take the "un" out of entropic uncertainty, or discovered some other useful quirk in this universe.

A tip of the Lemming's hat to Jeff Stevens, on Google Plus, for the heads-up on Lockheed's reactor.

More-or-less-related posts:

No comments:

Unique, innovative candles

Visit us online:
Spiral Light CandleFind a Retailer
Spiral Light Candle online store

Pinterest: From the Man Behind the Lemming

Top 10 Most-Viewed Posts

Today's News! Some of it, anyway

Actually, some of yesterday's news may be here. Or maybe last week's.
The software and science stuff might still be interesting, though. Or not.
The Lemming thinks it's interesting: Your experience may vary.
("Following" list moved here, after Blogger changed formats)

Who Follows the Lemming?


Family Blogs - Blog Catalog Blog Directory