Inside every engineer, Qati thought, was a frustrated teacher. "But what do they do?"

"Also, the first emission off the Primary is massive gamma radiation. Just behind that are the X-rays. In both cases, we are talking about high-energy photons, quantum particles which carry energy but which have no mass -"

"Light waves," Bock said, remembering his Gymnasium physics. Fromm nodded.

"Correct. Extremely energetic light waves of a different - higher - frequency. Now, we have this vast amount of energy radiating from the Primary. Some we can reflect or warp towards the Secondary by use of the channels we have built. Most is lost, of course, but the fact is that we will have so much energy at our fingertips that we need only a small fraction of it. The X-rays sweep down the straws. Much of their energy is absorbed by the metallic coatings, while the oblique surfaces reflect some further down, allowing further energy absorption. The polyethylene also absorbs a good deal of energy. And what do you suppose happens?"

"Absorb that much energy, and it must explode, of course," Bock said, before Qati could.

"Very good, Herr Bock. When the straws explode - actually they convert into plasma, but having split straws, we will not split hairs, eh? - the plasma expands radially to their axes, thus converting the axial energy from the Primary into radial energy imploding on the Secondary."

The lightbulb went on in Qati's head. "Brilliant, but you lose half of the energy, that part expanding outward."

"Yes and no. It still makes an energy barrier, and that is what we need. Next, the uranium fins around the body of the Secondary are also converted to plasma - from the same energy flux, but more slowly than the straws due to their mass. This plasma has far greater density, and is pressed inward. Within the actual Secondary casing, there is two centimeters of vacuum, since that space will be evacuated. So, we have a "running start" for the plasma that is racing inward."

"So, you use the energy from the Primary, redirected into a right-angle turn to perform the same function on the Secondary that is first done by chemical explosives?" Qati saw.

"Excellent, Commander!" Fromm replied, just patronizingly enough to be noticed. "We now have a relatively heavy mass of plasma pressing inward. The vacuum gap gives it room to accelerate before slamming into the Secondary. This compresses the Secondary. The secondary assembly is lithium-deuteride and lithium-hydride, both doped with tritium, surrounded by uranium 238. This assembly is crushed violently by the imploding plasma. It is also being bombarded by neutrons from the Primary, of course. The combination of heat, pressure, and neutron bombardment causes the lithium to fission into tritium. The tritium immediately begins the fusion process, generating vast quantities of high-energy neutrons along with the liberated energy. The neutrons attack the U238, causing a fast-fission reaction, adding to the overall Secondary yield."

"The key, as Herr Fromm said," Ghosn explained, "is managing the energy."