The DoD booklet Soviet Military Power ($6.50 from Govt. Prints. Off., Washington, DC 20402) is a sober assessment of Soviet strength, including their quest for technological superiority. (It does not spell out what to do about it, though informed opinion is clear on this: abandon the MAD non-strategy that points missiles at the wrong targets and cannot possibly ever be used; and deter by ABM systems and all other measures making it clear that the US has both the means and the will to survive and win a nuclear war if attacked.)
The booklet's brief section on directed energy
¾laser or particle beams for incapacitating a target¾points out that the Soviet high-energy laser program is three to five times the US effort, and may have advanced enough to field tactical medium-powered anti-aircraft and anti-personnel laser weapons by the mid-80's, followed by high-powered weapons based on land, ships, and in space by the end of the decade.There have been two reasons in the past why "death rays" of beamed energy have been limited to science fiction; but from the very beginning let us avoid a widespread and well-exploited misconception. The death ray is also a life ray: engineers have long dreamed of transmitting energy from one point to another without the nuisance of power lines or pipelines, let alone transporting fuel by rail or road. But as with the pulley, nuclear energy, radar or the sugar beet (continental Europe's answer to the British blockade in the Napoleonic wars), some good things first make their appearance in warfare, and the life ray may be destined for birth as a death ray first.
The two reasons were beaming and propagation. The major obstacle was the problem of concentrating high energies into a very thin beam
¾making large amounts of power flow through a small cross-section. A second obstacle is the medium through which the beam passes; it may absorb much of its energy before it reaches its target. In space, this obstacle is side-stepped, for a vacuum cannot absorb energy, nor scatter it out of the beam into which it was directed. However, very high-energy particles may also be able to pass through the atmosphere, almost literally poking a hole through it and allowing subsequent particles to pass through with comparatively small losses.To concentrate radiated energy into a very narrow beam, two conditions must be met. The radiation must be in the form of an orderly wave motion, and the concentrators (such as mirrors or lenses) must be many thousands of times larger than a wavelength of the radiation.
Radio waves, for example, are produced as neat, orderly waves, but even the shortest ones (an inch or less) require a large dish antenna to concentrate them, yet the beam still diverges slightly. Only a microwatt or so arrives at the receiving antenna from the satellites relaying TV and telephone channels, for example; a million times more misses the antenna and is uselessly dissipated. The energy of radio waves can thus be used for signaling, but not for transferring significant amounts of work capacity.
Light is the same type of radiation, but with a wavelength about a million times shorter (it is this difference that makes it visible), so that a two-inch mirror is a hundred thousand light wavelengths long. However, until the advent of the laser, light could not be produced as an orderly wave motion. Its individual energy packages, or photons, were like an unruly mob in a galley, each member pulling his oar when he was good and ready. That made the ship move forward, but erratically and lazily. What the laser did was put exact timing into the light waves
¾each oarsman pulling in exact synchronism with all of the others. It was still the same ship, but now the ship shot powerfully forward through the waves.So also is laser light still light, but powerful and capable of being concentrated into very thin, strictly parallel beams.
In the early sixties, lasers of up to a milliwatt became commercially available, and even then it seemed uncanny that a mere milliwatt of its red light could be seen from far away in broad daylight. But US lasers now under construction will pack an energy of 35 kilojoules into a sub-microsecond pulse, and if you have sent us your self-addressed, stamped envelope for our energy data sheet, you will easily find that 35 kJ equals 25,811 ft-lbs, or the energy that will lift 12.9 tons through one foot.
And the Russians are thought to be far beyond that.
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Vol. 9, No. 4
Newsletter: Access to Energy Newsletter Archive Volume: Issues Issue/No.: Vol. 9, No. 4 Date: November 23, 2004 01:19 PM (For actual publication date see newsletter.) Title: The vermin in the coattails
Copyright © 2004 - Access to Energy Newsletter Archive
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