The Cardinal of the Kremlin - By Tom Clancy Page 0,69

that you can use electromagnets to oscillate the electrons crosswise to their path. What you get is a beam of light coincident with the oscillation frequency of the wiggler magnets-that means you can tune it, sir, like a radio. By altering the energy of the beam, you can select the exact light frequency you generate. Then you can recycle the electrons back into the linear accelerator and shoot them back into the lasing cavity again. Since the electrons are already in a high-energy state, you gain a lot of power efficiency right there. The bottom line, sir, is that you can theoretically pump out forty percent of the energy you pump in. If you can achieve that reliably, you can kill anything you can see-when we talk about high energy levels, sir, we're speaking in relative terms. Compared to the electrical power that this country uses to cook food, the amount needed for a laser defense system is negligible. The trick is making it really work. We haven't done that yet."

"Why not?" The President was interested now, leaning forward slightly in his chair.

"We're still learning how to make the laser work, sir. The fundamental problem is in the lasing cavity-that's where the energy comes off the electrons and turns into a beam of light. We haven't been able yet to make a very wide one. If the cavity is too narrow, then you have such a high power density that you fry the optical coatings both in the cavity itself and on the mirrors that you use to aim the beam."

"But they've beaten the problem. How do you think they i did it?"

"I know what we're trying to do. As you draw energy into the laser beam, the electrons become less energetic, okay? That means you have to taper the magnetic field that contains them-and remember that at the same time you have to continue the wiggling action of the field, too. We haven't figured that out yet. Probably they have, and that probably came from their research into fusion power. All the ideas for getting energy out of controlled fusion are concerned with using a magnetic field to contain a mass of high-energy plasma-in principle the same thing we're trying to do with the free electrons. Most of the basic research in that field comes from Russia, sir. They're ahead of us because they've spent more time and money in the most important place."

"Okay, thank you, Major." The President turned to Judge Moore. "Arthur, what does CIA think?"

"Well, we're not going to disagree with Major Gregory-he just spent a day briefing our Science and Technology people. We have confirmed that the Soviets do have six free-electron lasers at this place. They have made a breakthrough in power output and we're trying to find out exactly what the breakthrough was."

"Can you do that?" General Parks asked.

"I said we're trying, General. If we're very lucky, we'll have an answer by the end of the month."

"Okay, we know they can build a very powerful laser," the President said. "Next question: is it a weapon?"

"Probably not, Mr. President," General Parks said. "At least not yet. They still have a problem with thermal blooming because they haven't learned how to copy our adaptive optics. They've gotten a lot of technology from the West, but so far they don't have that. Until they do, they can't use the ground-based laser as we have, that is, relaying the beam by orbiting mirror to a distant target. But what they have now can probably do great damage to a satellite in low-earth orbit. There are ways to protect satellites against that, of course, but it's the old battle between heavier armor and heavier warheads. The warhead usually wins in the end."

"Which is why we should negotiate the weapons out of existence." Ernie Alien spoke for the first time. General Parks looked over to him with unconcealed irritation. "Mr. President, we are now getting a taste-just a taste-of how dangerous and destabilizing these weapons might be. If we merely consider this Dushanbe place to be an antisatellite weapon, look at the implications it has for verification of arms-treaty compliance, and for intelligence-gathering in general. If we don't try to stop these things now, all we'll get is chaos."

"You can't stop progress," Parks observed.

Alien snorted. "Progress? Hell, we have a draft treaty on the table now to reduce weapons by half. That's progress, General. In the test you just ran over the South Atlantic, you missed with half your