US Navy boffins say they have achieved a major milestone in their quest to build an invincible raygun battleship.

The breakthrough comes in the Free Electron Laser (FEL) project, intended to produce an electrically powered, megawatt-range laser able to sweep the skies of pesky aircraft, hypersonic shipkiller missiles etc. Specifically, the Office of Naval Research reports that its boffins working at the Los Alamos National Lab in New Mexico have demonstrated "an injector capable of producing the electrons needed to generate megawatt-class laser beams".

Here's an ONR vid about the research:

"We were so happy to see our design, fabrication and testing efforts finally come to fruition," gushed Dr Dinh Nguyen, FEL chief at Los Alamos. "We're currently working to measure the properties of the continuous electron beams, and hope to set a world record for the average current."

The FEL, as its name suggests, needs a powerful supply of electrons. These are passed through magnetic fields to generate a laser beam, so avoiding the troublesome chemical fuels required in gas lasers like the one in the jumbo-jet Airborne Laser Testbed, and perhaps evading the many snags (particularly overheating) that come with normal solid-state lasers. FELs, too, would be "tunable" - able to change frequency to offer the best possible penetration of clouds, spray, rain etc.

Even so, the FEL programme has been underway since the 1980s without showing any signs of getting up to the megawatt power that would make it a viable warship weapon. Thus far the most powerful prototype built has offered a puny 14 kilowatts. Nonetheless, the Office of Naval Research has convinced US naval bigwigs that they can now successfully scale the weapon up into the big time.

The maritime warboffins are very excited about the injector breakthrough, which came much earlier than the schedule called for.

"This is a major leap forward for the program and for FEL technology throughout the Navy," says Quentin Salter, overall FEL chief. "The fact that the team is nine months ahead of schedule provides us plenty of time to reach our goals."

The raygun team hope to test a full-power prototype laser turret at sea as soon as 2018. Future generations of warship are to have electrical transmissions for their propulsion, so they would potentially be able to supply the huge amounts of 'leccy required by their laser batteries - though at the cost of briefly slowing down or coasting.

Powerful megawatt beams could potentially blast fast-moving targets out of the sky almost instantly, largely negating the threat of supersonic (or in future hypersonic) missiles skimming the sea to knock out ships. Mere aircraft would have no chance. The only things which might be able to penetrate a major warship's laser defences would be heavy armour piercing cannon shells, mostly or entirely made of solid metal - or perhaps one day hypersonic railgun projectiles, again much more difficult for a laser to destroy than a thin-walled missile or aircraft packed with explosive fuels and warhead.

Thus the FEL, if successful, offers the prospect that surface combatant warships - destroyers, cruisers and perhaps future battleship-class dreadnoughts - might be restored to their lost dominance over the oceans, unseating the pesky aircraft carrier and swaggering naval aviators. You can see why large parts of the US Navy are interested in this. ®

Bootnote

Promising as FEL looks, it seems unlikely to be of much use for head-mounted shark application. As we've noted on these pages before, what with the cumbersome laser machinery and large power source, one would really be looking more at a kind of raygun semi-submersible U-boat or barge with a more or less superfluous shark attached.

As ever, some kind of vast, whale-sized prehistoric megashark - perhaps crossed with electric eels using genetic-meddling abomination technology to furnish the necessary colosssal amounts of biological electricity - would seem much more practical than any normal execution-pool denizen.