The sum of all fears - Tom Clancy [179]
"The tools must be so rigid?" Ghosn asked. Fromm shook his head.
"Quite the reverse. The tools float on a cushion of air."
"But you said they weigh over a ton each!" Qati objected.
"Floating them on an air cushion is trivial, you've seen photographs of hovercraft weighing a hundred tons. Floating them is necessary to dampen out vibrations from the earth."
"What tolerances are we seeking?" Ghosn asked.
"Roughly what one needs for an astronomical telescope," the German replied.
"But, the original bombs -"
Fromm cut Ghosn off. "The original American bombs on Hiroshima and Nagasaki were crude embarrassments. They wasted almost all of their reaction mass, especially the Hiroshima weapon - you would not manufacture so crude a weapon any more than you would design a bomb with a burning gunpowder fuse, eh?
"In any case, you cannot use such a wasteful design," Fromm went on. "After the first bombs, the American engineers had to face the problem that they had limited supplies of fissile material. That few kilos of plutonium over there is the most expensive material in the world. The plant needed to make it through nuclear bombardment costs billions, then comes the additional cost of separation, another plant, and another billion. Only America had the money to do the initial project. Everyone in the world knew about nuclear fission - it was no secret, what real secrets are there in physics, eh? - but only America had the money and resources to make the attempt. And the people." Fromm added. "What people they had! So, the first bombs - they made three, by the way - were designed to use all the available material, and because the main criterion was reliability, they were made to be crude, but effective. And they required the largest aircraft in the world to carry them.
"Also, then the war was won, and bomb-design became a professional study and not a frantic wartime project. The plutonium reactor they have at Hanford turned out only a few tens of kilos of plutonium per year at the time, and the Americans had to learn to use the material more efficiently. The Mark-12 bomb was one of the first really advanced designs, and the Israelis improved it somewhat. That bomb has five times the yield of the Hiroshima device for less than a fifth of the reaction mass - twenty-five-fold improvement in efficiency. And we can improve that by almost a factor of ten.
"Now a really expert design team, with the proper facilities could advance that by another factor of perhaps four. Modern warheads are the most elegant, the most fascinating-"
"Two megatons?" Ghosn asked. Was it possible?
"We cannot do it here," Fromm said, the sorrow manifest in his voice. "The available information is insufficient. The physics are straightforward, but there are engineering concerns, and there are no published articles to aid us in the bomb-design process. Remember that warhead tests are being carried out even today to make the bombs smaller and yet more efficient. One must experiment in this field, as with any other, and we cannot experiment. Nor do we have the time or money to train technicians to execute the design. I could come up with a theoretical design for a megaton-plus device, but in truth it would have only a fifty-percent likelihood of success. Perhaps a little more, but it would not be a practical undertaking without a proper experimental-test program."
"What can you do?" Qati asked.
"I can make this into a weapon with a nominal yield of between four hundred and five hundred kilotons. It will be roughly a cubic meter in size and weigh roughly five hundred kilos." Fromm paused to read the looks on their faces. "It will not be an elegant device, and it will be overly bulky and heavy. It will also be quite powerful." It would be far more clever in design than anything American or Russian technicians had managed in the first fifteen years of the nuclear age, and that, Fromm thought, wasn't bad at all.
"Explosive containment?"