We've got a pretty good handle on creating short fusion reactions — just look at the H-bomb. But in the 60 years since the weapon's invention, we still haven't figured out sustained fusion reactions — the holy grail of energy production. A new high-power laser on the OSU campus could soon help solve that scientific conundrum.
Devised and built over the last six years by a team at the the High Energy Density Physics lab at Ohio State University and funded by a $US6 million Department of Energy grant, the laser will begin live testing on May 15.
The OSU laser will fire at a higher energy than the National Ignition Facility at Lawrence Livermore Labs — 500 trillion watts vs 411 trillion watts — but will do so for a much shorter period — a billionth of a second for the NIF, 30 million-billionths for the OSU.
This means that the OSU facility will be able to fire 100 times as many test shots in a day — literally one hundred shots to one — as the NIF. It will also do so at a greatly reduced cost (given the NIF soaked up $US4 billion in its construction) even if a single OSU shot does constitute the same energy as the electrical output of the northeastern US power grid.
As the OSU site explains,
This is where the Fast Fusion concept comes in: in Fast Fusion the "trigger" for the fusion within the compressed pellet is the arrival of an ultra-intense laser pulse of nominally 50kJ energy, with a pulse length of 20 picoseconds. There are many notional advantages in the fast fusion concept: The pellet no longer has to be so precisely manufactured, the energy of the compression lasers can be reduced up to an order of magnitude, and the concept lends itself to the relatively rapid sequencing required for an energy source.
The data generated by these lasers will be used to increase the National Ignition Facility's precision for its own forthcoming fusion experiments later this year. And good thing too — every laser shot by the NIF costs taxpayers a cool $US200,000. [OSU via Columbus Dispatch]