Jack Ryan 7 - The Sum of All Fears (95 page)

But the fission process had scarcely begun.

Some of the gamma rays, traveling at the speed of light, were outside the bomb case while the plutonium was still being compressed by the explosives. Even nuclear reactions take time. Other gamma rays started to impact on the Secondary. The majority of the gammas streaked through a gas cloud that only a few microseconds earlier had been the chemical explosive blocks, heating it far beyond the temperatures chemicals alone could achieve. Made up of very light atoms like carbon and oxygen, this cloud emitted a vast quantity of low-frequency “soft” X-rays. To this point, the device was functioning exactly as Fromm and Ghosn had planned.

The fission process was seven nanoseconds—0.7 shakes—old when something went wrong.

Radiation from the fissioning plutonium blazed in on the tritium-impregnated lithium-deuteride that occupied the geometric center of the Pit. The reason Manfred Fromm had left the tritium extraction to last lay in his basic engineer's conservatism. Tritium is an unstable gas, with a half-life of 12.3 years, meaning that a quantity of pure tritium will, after that time, be composed half of tritium and half of 3He. Called “helium-three,” 3He is a form of that second-lightest of elements whose nucleus lacks an extra neutron, and craves another. By filtering the gas through a thin block of palladium, the 3He would have been easily separated out, but Ghosn hadn't known about that. As a result, more than a fifth of the tritium was the wrong material. It could hardly have been a worse material.

The intense bombardment from the adjacent fission reaction seared the lithium compound. Normally a material half the density of salt, it was compressed to a metallic state that exceeded the density of the earth's core. What began was actually a fusion reaction, though a small one, releasing huge quantities of new neutrons, and also changing many of the lithium atoms into more tritium, which broke down—“fused”—under the intense pressure to release yet more neutrons. The additional neutrons generated were supposed to invade the plutonium mass, boosting the Alpha and causing at least a doubling of the weapon's unboosted fission yield. This had been the first method of increasing the power of the second-generation nuclear weapons. But the presence of 3He poisoned the reaction, trapping nearly a quarter of the high-energy neutrons in uselessly stable helium atoms.

For several more nanoseconds, this did not matter. The plutonium was still increasing its reaction rate, still doubling, still increasing its Alpha at a rate only expressible numerically.

Energy was now flooding into the Secondary. The metallically-coated straws flashed to plasma, pressing inward on the Secondary. Radiant energy in quantities not found on the surface of the sun vaporized but also reflected off elliptical surfaces, delivering yet more energy to the Secondary assembly, called the Holraum. The plasma from the immolated straws pounded inward towards the second reservoir of lithium compounds. The dense uranium 238 fins just outside the Secondary pit also flashed to dense plasma, driving inward through the vacuum, then striking and compressing the tubular containment of more 238U around the central container which held the largest quantity of lithium-deuteride/tritium. The forces were immense, and the structure was pounded with a degree of pressure greater than that of a healthy stellar core.

But not enough.

The Primary's reaction had already slackened. Starved of neutrons by the presence of the 3He poison, the bomb's explosive force began to blow apart the reaction mass as soon as the physical forces reached their balance. The chain reaction reached a moment of stability, at last unable to sustain its geometric rate of growth; the last two chain-reaction doublings were lost entirely, and what should have been a total Primary yield of seventy thousand tons of TNT was halved, halved again, and in fact ended with a total yield of eleven thousand two hundred tons of high explosive.

Fromm's design had been as perfect as the circumstances and materials allowed. An equivalent weapon less than a quarter the size was possible, but his specifications were more than adequate. A massive safety factor in the energy budget had been planned for. Even a thirty kiloton yield would have been enough to ignite the “sparkplug” in the Secondary to start a massive fusion “burn,” but thirty-KT was not reached. The bomb was technically called a “fizzle.”

But it was a fizzle equivalent to eleven thousand two hundred tons of TNT. That could be represented by a cube of high explosives seventy-five feet high, seventy-five feet long, and seventy-five feet thick, as much as could be carried by nearly four hundred trucks, or one medium-sized ship—but conventional explosives could never have detonated with anything approaching this deadly efficiency; in fact, a conventional explosion of this magnitude is a practical impossibility. For all that, it was still a fizzle.

As yet no perceptible physical effects had even left the bomb case, much less the truck. The steel case remained largely intact, though that would rapidly change. Gamma radiation had already escaped, along with X-rays, but these were invisible. Visible light had not yet emerged from the plasma cloud that had only three “shakes” before been over a thousand pounds of exquisitely designed hardware . . . and yet, everything that was to happen had already taken place. All that remained now was the distribution of the energy already released by natural laws which neither knew nor cared about the purposes of their manipulators.

— 36 —

WEAPONS EFFECTS

Sergeant Ed Yankevich should have been the first to notice what was happening. His eyes were on the van, and he was walking in that direction, scarcely forty feet away, but the human nervous system works in milliseconds and no faster.

The fizzle had just ended when the first radiation reached the police officer. These were gamma rays, which are actually photons, the same stuff that light waves are made of, but far more energetic. They were already attacking the body of the truck as well, causing the sheet steel to fluoresce like neon. Immediately behind the gammas were X-rays, also composed of photons but less energetic. The difference was lost on Yankevich, who would be the first to die. The intense radiation was most readily absorbed by his bones, which rapidly heated to incandescence, while at the same time the neurons of his brain were simultaneously excited as though each had become a flashbulb. In fact, Sergeant Yankevich was unable to notice a thing. He literally disintegrated, exploded from within by the tiny fraction of energy his body was able to absorb as the rest raced through him. But the gammas and X-rays were heading in all possible directions at the speed of light, and their next effect was one no one had anticipated.

Adjacent to the van, whose body was now being reduced to molecular bits of metal, was ABC's “A” satellite unit. Inside were several people who would have no more time to sense their fate than Sergeant Yankevich. The same was true of the elaborate and expensive electrical equipment in the van. But at the rear of this vehicle, pointing south and upward was a large parabolic-dish antenna, not unlike the kind used for radar. In the center of this, like the stamen of a flower, was the wave guide, essentially a metal tube with a square cross-section, whose inside dimensions roughly approximated the wavelength of the signal it was now broadcasting to a satellite 22,600 miles over the equator.

The wave guide of the A unit, and soon thereafter each of the eleven trucks lined up west of it, was struck by the gammas and X-rays. In the process, electrons were blasted off the atoms of the metal—in some cases the guides were lined with gold plate, which accentuated the process—which gave up their energy at once in the form of photons. These photons formed waves whose frequency was roughly that of the satellite uplink transmitters. There was one difference: the uplink trucks were in no case transmitting as much as one thousand watts of radio-frequency—RF—energy, and in most cases far less than that. The energy transfer from the A unit's wave guide, however, released nearly a million watts of energy in one brief, orgasmic pulse that ended in less than a microsecond as the antenna and the associated truck were also vaporized by the searing energy front. Next to go was the ABC “B” unit, then TWI. NHK, which was sending the Superbowl to Japan, was the fourth van in the line. There were eight more. All were destroyed. This process took approximately fifteen “shakes.” The satellites to which they transmitted were a long distance away. It would take the energy roughly an eighth of a second to span the distance, a relative eternity.

Next to emerge from the explosion—the truck was now part of it—was light and heat energy. The first blast of light escaped just before the expanding fireball blocked it. The second installment escaped soon thereafter, radiating in all directions. This generated the two-phase pulse which is characteristic of nuclear detonations.

The next energy effect was blast. This was actually a secondary effect. The air absorbed much of the soft X-rays and was burned into an opaque mass which stopped further electromagnetic radiation, transforming it into mechanical energy that expanded at several times the speed of sound, but before that energy had a chance to damage anything, more distant events were already under way.

The primary ABC video link was actually by fiberoptic cable—a high-quality landline—but the cable ran through the A van and was cut even before the stadium itself was damaged. The backup link was through the Telstar 301 satellite, and the Pacific Coast was serviced by Telstar 302. ABC used the Net-1 and Net-2 primary links on each bird. Also using Telstar 301 was Trans World International, which represented the NFL's worldwide rights and distributed the game to most of
Europe
, plus
Israel
and
Egypt
. TWI sent the same video signal to all its European clients, and also provided facilities for separate audio uplinks in the various European languages, which usually meant more than one audio link per country. Spain, for example, accounted for five dialects, each of which had its own audio sideband-channel. NHK, broadcasting to
Japan
, used both the JISO-F2R satellite and its regular full-time link, Westar 4, which was owned and operated by Hughes Aerospace. Italian TV used Major Path 1 of the Teleglobe satellite (owned by the Intelsat conglomerate) to feed its own viewers, plus those in
Dubai
and whatever Israelis didn't like the play-by-play through TWI and Telstar. Teleglobe's Major Path 2 was delegated to serve most of
South America
. Also present, either right at the stadium or a short distance away, were CNN, ABC's own news division, CBS Newsnet, and ESPN. Local
Denver
stations had their own satellite trucks on the scene, their uses mainly rented to outsiders.

There was a total of 37 active satellite uplink trucks using either microwave or Ku-band transmitters to generate a total of 48 active video, and 168 active audio signals, all feeding over a billion sports fans in seventy-one countries when the gamma and X-ray flux struck. In most cases, the impact generated a signal in the wave guides, but in six trucks, the traveling-wave tubes themselves were illuminated first and put out a gigantic pulse on exactly the proper frequencies. Even that was beside the point, however. Resonances and otherwise inconsequential irregularities within the wave guides meant that wide segments of the satellites orbiting over the Western Hemisphere were being worked by the TV crews at Denver. What happened to them is expressed simply. Their sensitive antennas were designed to receive billionths of watts. Instead, they were suddenly bombarded with between one and ten thousand times that on many separate channels. That surge overloaded an equal number of the front-end amplifiers inside the satellites. The computer software running the satellites took note of this and began to activate isolation switches to protect the sensitive equipment from the spike. Had the incident affected merely one such receiver, service would have been restored at once and nothing further would have happened, but commercial communications satellites are immensely expensive artifacts, costing hundreds of millions of dollars to build, and hundreds of millions more to launch into orbit. When more than five amplifiers recorded spikes, the software automatically began shutting circuits down, lest possibly serious damage to the entire satellite result. When twenty or more were affected, the software took the further step of deactivating all onboard circuits, and next firing off an emergency signal to its command ground station to say that something very serious had just happened. The safety software on the satellites were all customized variations of a single, very conservative program designed to safeguard billions of dollars' worth of nearly irreplaceable assets. In a brief flicker of time, a sizable fraction of the world's satellite communications dropped out of existence. Cable television and telecommunications systems all ceased, even before the technicians who managed their operations knew that something had gone disastrously wrong.

Pete Dawkins was resting for a moment. He thought of it as protecting the armored truck. The Wells Fargo guard was off delivering another few hundred pounds of quarters, and the police officer was sitting, his back against the shelves full of coin bags, listening to his radio. The Chargers were coming up to the line for a third-and-five at the Vikings' forty-seven. At that moment, the darkening sky outside turned incandescent yellow, then red—not the friendly, gentle red of a sunset, but a searing violet that was far brighter than that color could possibly have been. His mind barely had time to register that fact when it was assaulted by a million other things at once. The earth rose beneath him. The armored car was tossed up and sideways like a toy kicked by a child. The open rear door was slammed shut as if struck by a cannon. The body of the truck sheltered him from the shockwave—as did the body of the stadium, though Dawkins had not the time to realize it. Even so, he was nearly blinded by the flash that did reach him, and deafened by the overpressure wave that swept across him like the crushing hand of a giant. Had Dawkins been less disoriented, he might have thought earthquake, but even that idea did not occur to him. Survival did. The noise had not stopped, nor had the shaking, when he realized that he was trapped inside a vehicle whose fuel tank contained perhaps as much as fifty gallons of gasoline. He blinked his eyes clear and started crawling out the shattered windshield towards the brightest spot he could see. He did not notice that the backs of his hands looked worse than any sunburn he'd ever had. He did not realize that he could not hear a thing. All he cared about was getting to the light.