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Laser Fusion Passes Major Hurdle
chill writes "The National Ignition Facility at Lawrence Livermore National Laboratory has performed their first controlled fusion experiments using all 192 lasers. While still not ramped up to full power, the first experiments proved very fruitful. The lasers create a lot of plasma in the target container and researchers worried that the plasma would interfere with the ability of the target to absorb enough energy to ignite. These experiments show that not only does enough energy make it through, the plasma can be manipulated to increase the uniformity of compression. Ramping up of power is due to start in May." The project lead, Dr. Sigfried Glenzer, is "confident that with everything in place, ignition is on the horizon. He added, quite simply, 'It's going to happen this year.'"
Of course laser fusion can't provide a sustained burn for seconds, that's not how it works! Your car engine doesn't burn fuel in a sustained way, but it does a pretty good job of providing enough average power right?
The key point here it's a step towards getting gain in a fusion plasma. And hopefully in 2010. The earliest a tokamak is likely to achieve the same is 2020. The steps towards a powerplant are different for tokamaks and lasers, but high rep-rate lasers exist and projects like HiPER will look to address these issues.
I'm a physicist, I love these experiments, but...
The people running this thing need to think really, *really* hard how their comments play out in the media, maybe try and be a little more clear. The difference between getting fusion (the physical process) to work and getting fusion (the power generation system) to work is huge! Should they accomplish their goals in a year, they will still be a very long way away from thinking about building an electricity generating system. The line of "getting more power out than we put in" for fusion in the lab was crossed decades ago, and it's still unclear how doing this with yet another method of creating a fusion plasma is going to result in a more straightforward commercial reactor design.
This is how we end up with government officials who think we're all full of hyperbole, and don't actually do any work. I know they're fighting for their jobs at Livermore, but I don't see how they can keep this up long term. At some point, some Congressional committee is going to ask them to deliver on what has been promised, even if it was a confused, incorrect promise mis-translated by the media.
No, the gp was right but you misunderstood. "Ignition" means that the laser triggers a self-sustained reaction within the pellet. The laser fires once per pellet. By itself, the laser doesn't provide enough energy to fuse more than a tiny fraction of the atoms in the pellet before it explodes. Ignition means that the energy from the laser-triggered fusion helps sustain the temperature and pressure in the pellet long enough for a greater fraction of the atoms to fuse. I don' t know if the amount expected to fuse is a significant fraction of the total atoms in the pellet--I suspect not, but ignition means that many times more atoms fuse than would otherwise.