I scratched up the numbers-- these 30 femtosecond pulses are so brief that they don't have that "straight line" look one typically imagines laser beams to have. In fact, a 30 femtosecond (that's 30*10^-15 seconds) pulse is so brief that traveling at the speed of light (300x10^6 m/s), the beam only travels nine microns in its time switched on.
At 1.3 microns wide, this isn't a beam-- it's a pellet.
If the light is visible, that means its in the area of 600 nanometers in wavelength. How many wavelengths in that coherent beam, then? NOT MORE THAN 20.
It may be a 300 terawatt laser, but it runs for 30 femtoseconds, once every ten seconds. Each 300 terawatt pulse (assuming they don't use any energy before and after the pulse) uses 300x10^12 joules per second for 30x10^-15 seconds, or (get this) nine joules. If that's the only power drain for the laser, That's nine joules every ten seconds or less than one watt.
The laser then doesn't have to be "darken half the city" draining in all likelyhood, although I really doubt it's sitting there sipping down double-A batteries like a 0.9-watt LED array might.
So the really interesting thing about this laser isn't the idea of using it to melt tanks or blow Real Genius-style holes in half the city, but of using it to rip atoms and other particles asunder and see what they're made of. I can't help but think this'd make a great pickaxe for pecking at the inner structure of the subatomic realm-- our best answer for that is still throwing them up against a wall and watching the stuff that flies out.
More fun: let's apply Einstein's formula! E = m*c^2, which works backwards, so our nine-joule, 9 micron by 1.3 micron energy pulse weighs 9/(300x10^6*300x10^6) or 10^-16 kg, pretty light, but (let's pretend its a rectangle for a second) is only 105x10^-36 cubic meters, meaning it has a density of 10.5x10^21 kilograms per cubic meter-- that many times the density of water!
Any atoms that DO get in the direct path of that sucker are going to get CREAMED. Get your high speed cameras ready.
How coincidental, I just heard this morning about the NIF, which is trying to set up enough lasers to start nuclear fusion in a small pellet of fuel. Unfortunately, the HERCULES article talks about "300 times the capacity of the US power grid" and the NIF site talks about "1000 times the electrical generating capacity of the entire US", so I'm not sure how they directly compare.
They might be pumping it chemically, rather than electrically, and even so typically a pulsed laser is pumped continuously while the gate only allows it to lase every so often.
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(no subject)
Date: 2008-02-17 04:50 pm (UTC)(no subject)
Date: 2008-02-17 05:05 pm (UTC)At 1.3 microns wide, this isn't a beam-- it's a pellet.
If the light is visible, that means its in the area of 600 nanometers in wavelength. How many wavelengths in that coherent beam, then? NOT MORE THAN 20.
WOW, man. WOW.
(no subject)
Date: 2008-02-17 07:47 pm (UTC)(no subject)
Date: 2008-02-18 12:01 am (UTC)(no subject)
Date: 2008-02-18 05:48 am (UTC)(no subject)
Date: 2008-02-18 02:15 pm (UTC)(no subject)
Date: 2008-02-18 03:46 pm (UTC)The laser then doesn't have to be "darken half the city" draining in all likelyhood, although I really doubt it's sitting there sipping down double-A batteries like a 0.9-watt LED array might.
So the really interesting thing about this laser isn't the idea of using it to melt tanks or blow Real Genius-style holes in half the city, but of using it to rip atoms and other particles asunder and see what they're made of. I can't help but think this'd make a great pickaxe for pecking at the inner structure of the subatomic realm-- our best answer for that is still throwing them up against a wall and watching the stuff that flies out.
More fun: let's apply Einstein's formula! E = m*c^2, which works backwards, so our nine-joule, 9 micron by 1.3 micron energy pulse weighs 9/(300x10^6*300x10^6) or 10^-16 kg, pretty light, but (let's pretend its a rectangle for a second) is only 105x10^-36 cubic meters, meaning it has a density of 10.5x10^21 kilograms per cubic meter-- that many times the density of water!
Any atoms that DO get in the direct path of that sucker are going to get CREAMED. Get your high speed cameras ready.
National Ignition Facility
Date: 2008-02-18 06:59 pm (UTC)https://lasers.llnl.gov/
And now the greatest video game of all time speaks to me.
Date: 2008-02-18 07:24 pm (UTC)Khan.Fusion.
Har.
We.are.funny.see?
You.should.leave.now.
Har.
PS:
Date: 2008-02-18 07:26 pm (UTC)(no subject)
Date: 2008-02-18 07:29 pm (UTC)So that's still a hell of a lot denser than water. Just only 10.5 quadrillion times, not 10.5 million quadrillion.
(no subject)
Date: 2008-02-18 08:33 pm (UTC)But yeah, still really really dense.
Denser than a neutron star, in fact. (http://en.wikipedia.org/wiki/Neutron_star)
(no subject)
Date: 2008-02-19 07:11 am (UTC)I envy your math skills.
Even if it turns out that's all just basic algebra I've forgotten, still, wow.
(no subject)
Date: 2008-02-20 04:14 pm (UTC)