Scientists at the US Department of Energy's (DOE) Sandia National Laboratories (SNL) say that their preliminary tests of specially designed, magnetically imploded tubes called liners were successfully concluded recently.
The goal the SNL team set for itself is to achieve scientific “break-even” energies in nuclear fusion, which means that the amount of energy a reaction of this type produces needs to be equal to or higher than the amount of energy put in to start it.
It bears mentioning here that the only places where nuclear fusion occurs naturally are the cores of stars, under extreme pressure and at massive temperature levels. Recreating these conditions in the lab is proving to be quite challenging.
Within the next few years, the group not only wants to achieve break-even fusion, but also improve the parameters of the equation so that their reactors will produce more energy than used to start them.
Unlike fission, which sees the nuclei of uranium isotopes being broken apart in a chain reaction, nuclear fusion works by merging the nuclei of the hydrogen isotopes deuterium and tritium into helium, a process that is accompanied by the release of vast amounts of energy.
There are numerous ways to go about achieving nuclear fusion, but the method the SNL team chose is based on a concept called MagLIF, which stands for Magnetized Liner Inertial Fusion. The liners are an extremely important component in this approach.
In a paper accepted for publication in an upcoming issue of the esteemed journal Physical Review Letters, the team reveals that the critical components successfully withstood heavy electromagnetic implosion testing without losing too much of their integrity.
The exact terms the team used were that the “cylindrical beryllium liners remained reasonably intact.”
Now that this key trait has proven to be ready, experts will begin loading the liners with their deuterium and tritium fuels for some real testing, come 2013. If successful, the SNL team will be able to achieve fusion ahead of the more-renowned Nuclear Ignition Facility.
“The experimental results – the degree to which the imploding liner maintained its cylindrical integrity throughout its implosion – were consistent with results from earlier Sandia computer simulations. These predicted MagLIF will exceed scientific break-even,” says SNL lead researcher, Ryan McBride.