World's largest laser gears up for ignition (hydrogen fusion) experiments

[OKIsItJustMe]

https://publicaffairs.llnl.gov/news/news_releases/2009/NR-09-03-01.html

News Release

Contact: Lynda Seaver
Phone: [phone]
E-mail: [e-mail]

FOR IMMEDIATE RELEASE
March 6, 2009
NR-09-03-01

World's largest laser gears up for ignition experiments

LIVERMORE, Calif. - Construction of the National Ignition Facility (NIF), the world's largest and highest-energy laser system, was essentially completed on Feb. 26, when technicians at Lawrence Livermore National Laboratory (LLNL), where the laser is located, fired the first full system shot to the center of the NIF target chamber.

The test was the first time all 192 laser beams converged simultaneously in the 10-meter-diameter chamber. NIF has met all of its project completion criteria except for official certification of project completion by the U.S. Department of Energy, due by March 31.

"This a major milestone for the greater NIF team, for the nation and the world," said Edward Moses, LLNL's principal associate director for NIF & Photon Science. "We are well on our way to achieving what we set out to do - controlled, sustained nuclear fusion and energy gain for the first time ever in a laboratory setting."

"Although not required for formal completion of the NIF Project," added Project Director Ralph Patterson, "it is extremely satisfying to wind up the project by firing all beams."

An average of 420 joules of ultraviolet laser energy, known as 3-omega, was achieved for each beamline, for a total energy of more than 80 kilojoules (a joule is the energy needed to lift a small apple one meter against the Earth's gravity).

The energy level will be increased during the next several months, and when all NIF lasers are fired at full energy, they will deliver 1.8 megajoules of ultraviolet energy to a BB-sized target in a 20-nanosecond shaped laser pulse, generating 500 trillion watts of peak power -- more than the peak electrical generating power of the entire United States. This is considered more than enough energy to fuse the hydrogen isotopes of deuterium and tritium in the target into helium nuclei (alpha particles) and yield considerably more energy in the process than was required to initiate the reaction.

…

[Hope And Change]

1. K & R!

[FreakinDJ]

2. Fusion would end our Energy Dependence

Hope to see it in my life time

[RandomThoughts]

3. This isn't really related, but it reminds me of a thought I had a few years ago.

The eye differentiates light at I think 1/20 ratio. so if a light source is 20x other light sources below x candles of strength are ignored by the eye. I read that a few years ago.

So I was thinking of a way to make holographic projections. Take a obtuse v shaped wall of lasers on a floor pointing upward. Then each point in xyz space has at least 20 lasers pointed at it. Have a thin luminous mist float upward through the space the image will be projected in, to reflect the light.

Then very quickly cycle through the points that make up the holographic projection. Since each point will be a combination of 20+ lasers, its extra brightness will make it seen, and each individual laser path will be ignored by the mind. And by quickly strobing the lasers through the points that make up the image, you could make a real hologram. Even though each point would only be lit for a fraction of a second, the mist would hold the light energy for a short period, as would the eye.

The lasers might not need to be individual lasers, but like a tv cathode tube shooting on the phosphorous of a tv screen. Except they would be shooting to the mist in the air, and the combined brightness would come from multiple sources to keep the point lit, but not the streams to the point.

Does anyone think this would work?

(heh, Although I think I thought about this because this is also how thought in multiple stories seems to work)

[yourout]

5. Wow.....you must have slept at a Holiday Inn Express last night.

While by no means a technological novice this is way out of my pay grade.

Interesting and Hi brow stuff.

[Schema Thing]

6. sounds plausible

but who has mist when you need it?

[OKIsItJustMe]

7. SONY's way ahead of you

http://www.youtube.com/watch?v=YHDT8cfY6jA

[RandomThoughts]

9. Well not sure that is what it is billed as.

First a search of Sony corporate web page for hologram or nessie doesn't show anything, second first 5 pages of google hits on the topic are just web pages. It does seem to have gone viral, but one page said it was some marketing for a movie.

If it is not CG, if it is actually projected on some mist above the water, then the single angle of the camera would not show its 3d nature. Which tells me its not a clip meant to show its a hologram. See what I mean, if it was a hologram, they would have a moving camera to show that fact off, or at least multi views.

How do you show off a 3d hologram with one camera angle? you don't, So I think that video is something else.

Do you know of any tech article on that video.

[OKIsItJustMe]

11. It's just the largest example I've seen

http://features.csmonitor.com/innovation/2009/01/15/holograms-live-onstage/

…

Light has to bounce off something in order for human eyes to see the image. Scientists have developed several workarounds to create truly 3-D images, including mist, intersecting lasers, and spinning mirrors. But these techniques are too complex for regular use, Mr. Hsieh says.

…

http://dx.doi.org/10.1117/12.667359

[Ratty]

4. Purely for nuclear weapons testing and development

No fusion scientist believes inertial confinement is the path to harnessing fusion power for peaceful purposes. That's what magnetic confinement research is for. The Livermore laser program is for testing and development of nuclear weapons, nothing more.

[OKIsItJustMe]

8. Clearly, you have inside knowledge the public affairs officers at LLNL do not:

https://publicaffairs.llnl.gov/news/news_releases/2009/NR-09-03-01.html

…

By demonstrating the ability to attain fusion ignition in the laboratory, NIF will lay the groundwork for future decisions about fusion's long-term potential as a safe, virtually unlimited energy source. Fusion, the same energy source that powers the stars, produces no greenhouse gases and is environmentally more benign than fossil-fuel or nuclear-fission-based energy.

…

https://lasers.llnl.gov/missions/energy_for_the_future/

Energy for the Future

Harnessing the energy of the sun and stars to meet the Earth's energy needs has been a decades-long scientific and engineering challenge. While a self-sustaining fusion burn has been achieved for brief periods under experimental conditions, the amount of energy that went into creating it was greater than the amount of energy it generated. There was no energy gain, which is essential if fusion energy is ever to supply a continuous stream of electricity. If it is successful, the National Ignition Facility will be the first inertial confinement fusion facility to demonstrate ignition and a self-sustaining fusion burn. In the process, NIF's fusion targets will release ten to 100 times more energy than the amount of laser energy required to initiate the fusion reaction.

The nuclear power plants in use around the world today utilize fission, or the splitting of heavy atoms such as uranium, to release energy for electricity. A fusion power plant, on the other hand, will generate energy by fusing atoms of deuterium and tritium – two isotopes of hydrogen, the lightest element. Deuterium will be extracted from abundant seawater, and tritium will be produced by the transmutation of lithium, a common element in soil. When the hydrogen nuclei fuse under the intense temperatures and pressures in the NIF target capsule, a helium nucleus is formed and a small amount of mass lost in the reaction is converted to a large amount of energy according to Einstein's formula E=mc².

A fusion power plant would produce no greenhouse gas emissions, operate continuously to meet demand, and produce shorter-lived and less hazardous radioactive byproducts than current fission power plants. A fusion power plant would also present no danger of a meltdown.

Because nuclear fusion offers the potential for virtually unlimited safe and environmentally benign energy, the U.S. Department of Energy (DOE) has made fusion a key element in the nation's long-term energy plans.

The goal of the National Ignition Facility is to achieve fusion by compressing and heating a pea-sized capsule containing a mixture of deuterium and tritium with the energy of 192 powerful laser beams.

…

https://lasers.llnl.gov/programs/ife/how_ife_works.php

How IFE Works

In an IFE power plant, many (typically 5-10) pulses of fusion energy per second would heat a low-activation coolant, such as lithium-bearing liquid metals or molten salts, surrounding the fusion targets. The coolant in turn would transfer the fusion heat to a power conversion system (e.g., steam-based Rankine cycle or high pressure helium-based Brayton cycle) to produce electricity.



Only a few NIF experiments can be conducted in a single day because the facility's optical components need time to cool down between shots. In an IFE power plant, targets will be ignited five to ten times a second. The requirement to operate at high pulse repetition rates (rep-rate for short) poses significant R&D challenges:

Target Performance

Experiments on NIF will demonstrate energy gain – the ratio of fusion energy from the ICF target divided by laser energy input – greater than ten. Advanced targets that can be tested on NIF after the initial ignition campaign begins in 2010 may achieve gains of 50 or more. For IFE, a target gain greater than about 100 is needed in order to minimize the portion of generated electric power that has to be recirculated within the plant to operate the laser. https://lasers.llnl.gov/science_technology/fusion_science/fast_ignition.php">Fast ignition targets are expected to give gains of several hundred. A high recirculating power fraction means there is less power available for sale, so the cost of electricity will be higher.

Target Factory

The target factory must produce a continuous supply of high-quality targets at an acceptable cost – typically 25¢ for a target that produces 300 megajoules of energy. Many types of targets are being considered for laser IFE, including indirect-drive (like those that will be shot on NIF), direct-drive (currently being tested on the OMEGA laser at the University of Rochester), and advanced designs including fast ignition and shock ignition (see https://lasers.llnl.gov/programs/nic/target_fabrication.php">Target Fabrication). In all cases, the deuterium-tritium (D-T) fusion fuel is contained in a spherical fuel capsule. Near-term experiments planned for NIF will use capsules made of beryllium, carbon or carbon-hydrogen polymers, but for IFE plants, it is likely that polymer capsules will be the preferred material. The fuel capsule must be cold enough for D-T to freeze and form a layer of D-T ice on the inner wall of the capsule.

In direct-drive, the capsule is directly irradiated by the laser beams. In indirect-drive, the capsule is placed inside a hohlraum, a tiny, can-shaped container made with high-atomic-mass materials like gold and lead with holes on the ends for beam entry. If the power plant operates at five shots a second, the target factory will have to produce more than 400,000 targets a day. Detailed conceptual design studies for IFE target factories have been completed by http://www.ga.com/">General Atomics, a participant in the National Ignition Campaign.

Target Injection and Tracking

In NIF, targets are held in place at the center of the chamber and the beams are aligned to the ideal fixed position for each shot. For IFE, targets will have to be injected at speeds greater than 100 meters a second and tracked in flight to provide data to a real-time beam-pointing system needed to assure the precise illumination required to achieve ignition and high energy gain. Target injection experiments using gas guns have been conducted at General Atomics with room-temperature surrogates. Conceptual designs for other types of injectors, such as electromagnetic accelerators, and for target tracking and beam pointing systems have also been completed. While researchers are satisfied with progress to date, significant development remains to demonstrate that the requirements for IFE can be met.

High Rep-Rate Laser

A key component of a laser IFE power plant is of course the laser. While the total energy of the laser is likely to be comparable to or even less than that of NIF, the IFE laser must operate at five to ten shots a second depending on the target yield per shot and the desired electric output of the power plant. Currently two classes of laser are being considered in the United States: the krypton-fluoride (KrF) gas laser and the diode-pumped solid state laser (DPSSL). At LLNL, research is focused on the DPSSL, building on more than 35 years of experience with solid-state lasers leading up to NIF. In addition to the ability to operate at high rep-rates, key considerations for the IFE laser include high efficiency (preferably greater than 10 percent), low cost (to keep the cost of electricity competitive with other energy options), long-life optics, high reliability and low maintenance costs. The https://lasers.llnl.gov/programs/psa/fusion_energy/mercury.php">Mercury laser project has been LLNL's first step in developing a laser to meet those requirements. Lessons learned from Mercury, combined with new ideas on laser architecture and continuing improvements in components such as diode arrays and materials science, are setting the stage for the next step in DPSSL development: the design and construction of a single beamline that, if replicated 25 to 100 times, would provide the energy needed for IFE.

Fusion Chamber

Each fusion target releases a burst of fusion energy in the form of high-energy (14-million-electron-volt) neutrons (about 70 percent of the energy), X-rays and energetic ions.

An artist's rendition of a laser fusion power plant driven by diode-pumped solid-state lasers. Experiments at the National Ignition Facility will help clarify whether it is economically feasible to generate electricity by laser fusion.

The fusion chamber must contain this blast of energy and convert the sequences of energy pulses into a steady flow of power for the power conversion system. The chamber design must include a 50- to 100-centimeter-thick region that contains lithium (as a liquid metal, molten salt or solid compound) in order to produce tritium through nuclear reactions with the fusion neutrons. This region is called the breeding blanket and must produce at least one tritium atom for every tritium atom burned in the fusion target – a tritium breeding ratio equal to or greater than one. A key issue for the chamber is the survival of the innermost wall (first wall) that is exposed to intense heat and radiation from the target's X-rays, ions and neutrons. Various chamber designs have been proposed and fall into three major classes:

• Dry-wall, where the innermost surface is a solid material such as tungsten designed to handle the full target energy impact
• Wetted-wall, where a thin liquid layer coats the first wall and absorbs the short-range X-rays and ions before they can damage the wall
• Thick liquid wall, where more than 50 centimeters of liquid (lithium-bearing metal or molten salt) flows between the target and first wall and provides protection from X-rays, ions and neutrons.

Another key issue for the fusion chamber is intra-shot recovery: the conditions inside the chamber (such as vapor and droplet density) that must be recovered between each shot to the point that the next target can be injected and the laser beams can propagate through the chamber to the target. Finally, the chamber must operate at high temperature – more than 500 degrees Celsius – in order to achieve high efficiency in the power conversion system.

Power Conversion System

By flowing a coolant through the fusion chamber at a steady rate, the pulsed fusion energy can be extracted at a constant rate and delivered to the power conversion system, which converts the thermal power to electric power. When liquids such as lithium, lead-lithium alloys or the molten fluorine-lithium-beryllium molten salt "flibe" are used for tritium breeding, the liquid is generally circulated as the primary coolant for the fusion chamber. When solid breeders such as lithium-aluminate (LiAl02) are used, high-pressure helium serves as the chamber coolant. In either case, the primary coolant circulates through heat exchangers that power electric power equipment. The efficiency of the power conversion systems depends on the outlet temperature of the primary coolant, which is limited by the materials used in the construction of the chamber. With advanced material being developed for fusion and other applications, conversion efficiencies of 40 to 50 percent will be possible. Some work has also been done on ideas for converting a portion of the target energy output directly to electricity.

Separability and Integration

An advantage of IFE compared to magnetic fusion is that, at least in the early stages, the subsystems described above can be developed and tested separately and often at lower cost than fully integrated facilities. The IFE power plant, however, requires successful integration of all the components with careful attention to the interfaces and the impact of design choices for one system on the others. Using liquids in the chamber to protect the first wall, for example, introduces the issue of keeping liquid off the final optics.

Safety and Environment

As researchers develop concepts for IFE power plants, they are mindful of the need to develop safe and environmentally acceptable sources of energy. Use of low-activation materials and design options such as the thick liquid wall chamber can minimize the production of activated material over the life of the plant. Control of tritium will be important for any type of fusion power plant, since its release dominates consequences in analyses of hypothetical accident scenarios.

It must be very depressing for them to be shown to be so ill-informed.

[benEzra]

10. Fusion bombs are already perfected and have been for decades...

a half-megaton fusion warhead is smaller than a kitchen trash can and works every time. Problem is, it can't release energy gradually at a rate you can use to heat water for power generation.

A fusion reactor is entirely different from a fusion bomb.

And you cannot downsize laser-ignited fusion enough to make a bomb out of it; you simply cannot get those kinds of power densities in a small portable package.