New laser perhaps to enable Inertial Confiement Fusion?

[marvin57]

Fusion: X-ray laser zaps solid to 2 million degrees
http://www.google.com/hostednews/afp/ar ... 700c51.121

PARIS — The quest to create nuclear fusion may have come a step closer when scientists heated solid matter to two million degrees with the world's most powerful X-ray laser, a study reported Wednesday.

A team of researchers working at the SLAC National Accelerator Laboratory in Menlo Park, California used the rapid-fire laser -- a billion times brighter that any other man-made X-ray source -- to flash-heat a miniscule piece of aluminum foil.

In so doing, they created a form of plasma known as "hot dense matter," reaching temperatures hotter than two million degrees Celsius (3.6 million degrees Fahrenheit).

X-ray laser bakes solid plasma from aluminum foil, brings us closer to nuclear fusion
http://techbamboo.com/2012/01/26/x-ray- ... ar-fusion/

Scientists have long been able to create plasma from gases and study it with conventional lasers, said co-author Bob Nagler of SLAC, an LCLS instrument scientist. But no tools were available for doing the same at solid densities that cannot be penetrated by conventional laser beams.

“The LCLS, with its ultra-short wavelengths of X-ray laser light, is the first that can penetrate a dense solid and create a uniform patch of plasma –in this case a cube one-thousandth of a centimeter on a side –and probe it at the same time,” Nagler said.

[Skipjack]

Well, you might be able to do nuclear fusion with that, but I seriously doubt it will lead to a design for an economic reactor. I am not even sure you will get enough Q out of it to have a positive energy balance.

[marvin57]

Well, you might be able to do nuclear fusion with that, but I seriously doubt it will lead to a design for an economic reactor. I am not even sure you will get enough Q out of it to have a positive energy balance.

"Fast ignition" ICF is the possible solution to this concern.

http://en.wikipedia.org/wiki/Inertial_c ... rgy_source

Laser driven systems were initially believed to be able to generate commercially useful amounts of energy. However, as estimates of the energy required to reach ignition grew dramatically during the 1970s and '80s, these hopes were abandoned. Given the low efficiency of the laser amplification process (about 1 to 1.5%), and the losses in generation (steam-driven turbine systems are typically about 35% efficient), fusion gains would have to be on the order of 350 just to break even. These sorts of gains appeared to be impossible to generate, and ICF work turned primarily to weapons research. With the recent introduction of fast ignition, things have changed dramatically. In this approach gains of 100 are predicted in the first experimental device, HiPER. Given a gain of about 100 and a laser efficiency of about 1%, HiPER produces about the same amount of fusion energy as electrical energy was needed to create it.

Fast ignition and the first experimental device is discussed here:
http://en.wikipedia.org/wiki/HiPER#Fast ... _and_HiPER

In traditional ICF devices the driver laser is used to compress the target to very high densities. The shock wave created by this process further heats the compressed fuel when it collides in the center of the sphere. If the compression is symmetrical enough the increase in temperature can create conditions close to the Lawson criterion, leading to significant fusion energy production. If the resulting fusion rate is high enough, the energy released in these reactions will heat the surrounding fuel to similar temperatures, causing them to undergo fusion as well. In this case, known as "ignition", a significant portion of the fuel will undergo fusion and release large amounts of energy. Ignition is the basic goal of any fusion device.

The overall efficiency of this approach is many times that of the conventional approach. In the case of NIF the laser generates about 4 MJ of infrared power to create ignition that releases about 20 MJ of energy. This corresponds to a "fusion gain" —the ratio of input laser power to output fusion power— of about 5. If one uses the baseline assumptions for the current HiPER design, the two lasers (driver and heater) produce about 270 kJ in total, yet generate 25 to 30 MJ, a gain of about 100. Considering a variety of losses, the actual gain is predicted to be around 72. Not only does this outperform NIF by a wide margin, the smaller lasers are much less expensive to build as well. In terms of power-for-cost, HiPER is expected to be about an order of magnitude less expensive than conventional devices like NIF.

These calculations are done without this new laser, so using the new laser HiPER (using fast ignition) should be even more efficient. Neat, hey?

[Skipjack]

Even if it will have a high enough Q, it does not mean, it will be economic. Gold pellents, or even lead pellets (if they should work) dont simply appear out of nowhere...
Even their very optimistic assumptions put a powerplant in the mid 2030ies. I think we all know that this is not going to happen.

[marvin57]

Here we go, apparently Lasers plus a crushing magnetic field may make fusion more efficient.

[Skipjack]

And I still dont think it will ever be economic. It might work alright, but that does not mean it will be economic, just like Toks.

[KitemanSA]

So if you drop one of these things into a Polywell and zap it, will the well/MaGrid increase the total burn enough to make this thing Q>1?

I'm not thinking about the immediate effects, but will the well bring the plasma back for enough secondary burns to make any difference?