Powerful Laser For Fusion Research Nearing Completion

Discover Magazine has an article about the world's largest laser, currently nearing completion at the National Ignition Facility in Livermore, California. The laser, which has already shown the ability to fire four megajoules of infrared energy for up to 20 nanoseconds, is intended for fusion research.

The goal is to fire the powerful laser into both ends of a tiny gold capsule filled with two frozen hydrogen isotopes. The blast will create a plasma around the target in the center of the capsule, hopefully hot enough to cause the two hydrogen isotopes to fuse.

The researchers are currently testing the optics and expect to complete construction of the laser by March of next year. By 2010, they expect to reach a point where the fusion energy produced by the machine is greater than the energy used by the lasers, creating a net-positive energy fusion reaction.

Update on Emc2's WB-7 Polywell Fusion Experiment

Alan Boyle at Cosmic Log has an update on Emc2 Fusion's WB-7 Polywell fusion experiment. Emc2's Richard Nebel reveals progress made and says that WB-7 is up and running and producing data.

As to whether Polywell fusion will ever produce enough energy to justify its (relatively low) cost, it remains to be seen. But the good news is that the U.S. Navy has provided funding to push this work forward and continue the legacy of the late Dr. Robert Bussard. With any luck, WB-8 will be a more powerful reactor—possibly in the 100 MW range—that will prove that Polywell fusion is not only viable, but vastly more efficient than the ITER boondoggle.

Cold Fusion on the Comeback Trail?

Cold Fusion (in physics, not in web development) became a taboo expression nineteen years ago after Martin Fleischmann and Stanley Pons were unable to replicate their experiment that supposedly produced fusion in a glass jar at room temperature. And, since nobody else was able to duplicate the results, cold fusion has since become a synonym for pseudo-science. But that may be about to change.

Jon Cartwright of the physicsworld blog reports that Yoshiaki Arata, a retired physics professor at Osaka University and his partner, Yue-Chang Zhang, have demonstrated what appears to be a repeatable experiment that involves forcing deuterium into an evacuated cell containing a sample of palladium dispersed in zirconium oxide. According to Arata, the deuterium is absorbed by the sample in large enough amounts to force the deuterium nuclei to become close enough to fuse.

It's way, way too early to say whether or not these results have any validity, as (like with Fleischmann and Pons) they will need to be replicated by several other teams and the results fully understood. Additionally, the temperature of the sample only rose to about 70°C. While that is significant and notable, it is not enough to produce steam to turn a turbine, so more work would need to be done.

Also, there appears to be some debate as to whether the heating was actually caused by fusion or whether it was purely chemical. However, if deuterium is fed into the sample and helium comes out, I don't see any other process that could explain that. But more research will reveal the truth.