Fast Ignition Nears Reality

An international team using the Gekko XII Nd:glass laser at Osaka University in Suita, Japan, has presented experimental evidence supporting the feasibility of the fast-ignition scheme for inertial confinement fusion. In January, Photonics Spectra reported that the team had increased neutron yield by an order of magnitude using the fast-ignition targets. The current research indicates that scaling up the laser power continues to raise the yield.

In the new work, which appeared in the Aug. 29 issue of Nature, the researchers increased the heating pulse energy on target from 60 to 300 J. The neutron yield, an indicator of fusion products, improved by three orders of magnitude, suggesting that the temperature of the compressed plasma also approximately doubled, compared with no heating pulse.