Slashdot Mirror
67-Kilowatt Laser Unveiled
s31523 writes "Lawrence Livermore National Laboratory in California has announced they have working in the lab a Solid State Heat Capacity Laser that averages 67 kW. It is being developed for the military. The chief scientist Dr. Yamamoto is quoted: 'I know of no other solid state laser that has achieved 67 kW of average output power.' Although many lasers have peaked at higher capacities, getting the average sustained power to remain high is the tricky part. The article says that hitting the 100-kW level, at which point it would become interesting as a battlefield weapon, could be less than a year away."
1 micron is 1000nm, and will penetrate the eyeball just fine. It will not focus fully on the retina. 400-1400nm radiation will penetrate the eye ball and may cause heating of the retina, whereas exposure to laser radiation with wavelengths less than 400 nm and greater than 1400 nm are largely absorbed by the cornea and lens, leading to the development of cataracts or burn injuries.
"Fix it"
If your mirror is 99% reflective (which would be very, very good -- and it won't stay that way in a dusty dirty battlefield), you'd still be absorbing 1kW of power. Which might be very easy or very hard to dissipate, depending on the beam diameter and how well the targeting system can keep it on the same piece of armor. And, as soon as your armor starts to heat up more than a little, the reflectivity will drop and it will fail.
Everyone always thinks mirrors are an easy answer to laser weapons, but it's not really that simple; sure they're worth considering, but they're not obviously a winning strategy.
A better armor might actually be an ablative -- eg a phenolic or graphite plate that absorbs all the heat at the very surface, and vaporizes into a cloud of gas that then takes the majority of the heating while the armor continues ablating from conducted heat and laser heating that gets through -- meanwhile the targeting system frantically tries to keep the laser on the same spot long enough to punch all the way through, and the tank driver tries to conduct evasive action. Modern ablative technology for rocket engines can take 1kW/cm^2 of heating and last for minutes of service; ablatives derived from such technologies might make very effective armors.
The fact the SSHCL is able to get 67kW out of a solid state system is very impressive. Most solid state lasers of this sort have been stuck below 10kW and are only about 1% efficient, a 1kW laser needs 1MW of input power 99% of which needs to be shed by a cooling system. Solid state lasers have a definite advantage over chemical ones like the THEL and ABL because their "ammunition" supply is essentially only limited by the amount of electricity they've got available. Chemical lasers consumer reactants in the lasing process and have a finite number of shots before those reactants are exhausted. Those reactants take up a lot of space as well, Isreal's THEL system requires four semi trailers worth of equipment to shoot down small katyusha rockets and mortar rounds.
The Air Force has a real hard on for laser systems. Though it doesn't say specifically in the article it appears this lab was awarded the AFRL's contract to produce a solid state equivalent to the ATL system being developed largely by Boeing. The ATL is a smaller cousin of the ABL weighing in at about 70kW. It's an order of magnitude lower power than the roughly 1MW ABL but is also quite a bit smaller. The ABL requires a 747, the ATL is being developed to be mounted on a C-130 or V-22 Osprey. A solid state ATL would be far more useful for the Air Force than a chemical one. A solid state laser system on an aircraft could be powered by generators hooked to the engines and fired an indefinite number of times in flight.
I'm a loner Dottie, a Rebel.
there is little to no physical force behind it; the destructive energy is heat. Things won't explode like they do in Star Wars and other sci fi/fantasy movies and shows.
The satellite-based lasers for Star Wars (Reagan's wet dream, not the Movie) primarily worked by kinetic activity.
A cutting laser doesn't take anywhere near 67kW, but they work fairly slowly (slow enough for an armored target to take countermeasures). Instead, you want to basically vaporize a few nm of the surface, resulting in exactly the sort of explosion you say doesn't happen.
Search Google for "arc flash"... Though a much more mundane effect, it gives the general idea... Basically, if you vaporize copper bus bar by shorting it out, it produces a pretty impressive "explosion" due to the copper suddenly occupying 67,000 (no connection to the laser from the FP, just a coincidence) times its original volume.
Fucknut? Jesus, the ACs are really raising the bar today. Terrorists in Somalia? I heard it was an Islamic independence movement ... which is of course terrorism in US-speak.
China? Sorry, the US military budgets dwarfs them incredibly. The official US military budget accounts for 50% of the world's military budget. So they are outclassing you, but not in the way that you mean.