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The Navy's laser project hits a milestone. [Link]

“Five hundred [kilovolts] has been the project goal for a long time,” says George Neil, the FEL associate director at Jefferson Labs, whose Rav 4 license plate reads LASRMAN. “The injector area is one of the critical areas” of the whole project.

The free-electron laser is one of the Navy’s highest-priority weapons programs, and it’s not hard to see why. “We’re fast approaching the limits of our ability to hit maneuvering pieces of metal in the sky with other maneuvering pieces of metal,” says Rear Adm. Nevin Carr, the Navy’s chief of research. The next level: “fighting at the speed of light and hypersonics” — that is, the free-electron laser and the Navy’s Mach-8 electromagnetic rail gun.

Say goodbye to an adversary’s antiship missiles, and prepare to fire bullets from 200 miles away, far from shoreline defenses. No wonder the Navy asked Congress to double its budget for directed-energy weapons this week to $60 million, most of which will go to the free-electron laser.

It won’t be until the 2020s, Carr estimates, that a free-electron laser will be mounted on a ship. (Same goes for the rail gun.) Right now, the free-electron laser produces a 14-kilowatt beam. It needs to get to 100 kilowatts to be viable to defend a ship, the Navy thinks. But what happened at Jefferson Labs Friday shrinks the time necessary to get to 100 kilowatts and expands the lethality of the laser. Here’s why.

All lasers start off as atoms that get agitated into becoming photons, light that’s focused through some kind of medium, like chemicals or crystals, into a beam operating on a particular wavelength. But the free-electron laser is unique: It doesn’t use a medium, just supercharged electrons run through a racetrack of superconductors and magnets — an accelerator, to be technical — until it produces a beam that can operate on multiple wavelengths.

That means the beam from the free-electron laser won’t lose potency as it runs through all the crud in ocean air, because its operators will be able to adjust its wavelengths to compensate. And if you want to make it more powerful, all you need to do is add electrons.

But to add electrons, you need to inject pressure into your power source, so the electrons shake out and run through the racetrack. That’s done through a gun called an injector. In the basement of a building in Jefferson Labs, a 240-foot racetrack uses a 300-kilovolt injector to pressurize the electrons out of 200 kilowatts of power and send them shooting through the accelerator.

Currently, the free-electron laser project produces the most-powerful beam in the world, able to cut through 20 feet of steel per second. If it gets up to its ultimate goal, of generating a megawatt’s worth of laser power, it’ll be able to burn through 2,000 feet of steel per second. Just add electrons.