http://aviationweek.com/technology/skun ... or-detailsSkunk Works Reveals Compact Fusion Reactor Details
Lockheed Martin aims to develop compact reactor prototype in five years, production unit in 10
Oct 15, 2014 Guy Norris | Aviation Week & Space Technology

DoE has deep pockets for energy independence and you can bet Lockheed has picked them regularly.
This is the best article I've seen and indicates 5 years to prototype....They are confident of the lab results that they are on the correct track.
As to efficiency.....off the charts...
This is best comment of all....The 100-MW unit would provide sufficient power for up to 80,000 homes in a power-hungry U.S. city and is also “enough to run a ship,” he notes.
Lockheed estimates that less than 25 kg (55 lb.) of fuel would be required to run an entire year of operations. The fuel itself is also plentiful.
Deuterium is produced from sea water and is therefore considered unlimited, while tritium is “bred” from lithium. “We already mine enough lithium to supply a worldwide fleet of reactors, so with tritium you never have too much built up, and that’s what keeps it safe. Tritium would be a health risk if there were enough released, but it is safe enough in small quantities. You don’t need very much to run a reactor because it is a million times more powerful than a chemical reaction,” McGuire notes.
Fusion has always confronted the containment demon.....if they are confident enough to put company credibility at risk....there is truly something in this.Preliminary simulations and experimental results “have been very promising and positive,” McGuire says. “The latest is a magnetized ion confinement experiment, and preliminary measurements show the behavior looks like it is working correctly.
We are starting with the plasma confinement, and that’s where we are putting most of our effort.
One of the reasons we are becoming more vocal with our project is that we are building up our team as we start to tackle the other big problems. We need help and we want other people involved. It’s a global enterprise, and we are happy to be leaders in it.”
This all makes sense and there has been many strides forward in materials science and manufacturing to make this viable.
It's the scaling down that is stunning from my viewpoint.
Overall, McGuire says the Lockheed design “takes the good parts of a lot of designs.” It includes the high-beta configuration, the use of magnetic field lines arranged into linear ring “cusps” to confine the plasma and “the engineering simplicity of an axisymmetric mirror,” he says. The “axisymmetric mirror” is created by positioning zones of high magnetic field near each end of the vessel so that they reflect a significant fraction of plasma particles escaping along the axis of the CFR. “We also have a recirculation that is very similar to a Polywell concept,” he adds, referring to another promising avenue of fusion power research. A Polywell fusion reactor uses electromagnets to generate a magnetic field that traps electrons, creating a negative voltage, which then attracts positive ions. The resulting acceleration of the ions toward the negative center results in a collision and fusion.

It would be idiotic of a company like Lockheed to open up The Skunkworks without a solid expectation that further engineering will lead to success.