From The Jupiter Theft, by Donald Moffitt
The ritual spying had become a way of life during the year-long preparations for the joint Chinese-American Jupiter mission…The big prize in the game was the new boron fusion/fission engine that was going to power the Jupiter ship, courtesy of the United States. The Chinese didn’t have one yet…
Jameson was familiar with the basic principle: You inject a proton into boron 11, with its six neutrons and five protons, and you get an unstable nucleus that explodes into three helium nuclei, with two protons and two neutrons apiece, plus a liberated proton. But it took temperatures in the billions of degrees to start boron fission.
So to get the hot protons needed to trigger the boron reaction, you had to have a fusion reaction first. That was being supplied, courtesy of the Chinese, via a more conventional deuterium-tritium fusion triggered by carbon dioxide lasers.
The security problems at the interface of the two systems were nightmarish.
Some would say that science fiction rots the mind. And that was just the short form. A longer version (with high performance deep space rocket ship!) follows…
The Jupiter ship drifted among the stars, a gigantic hoop and stick perforated with light from its blazing ports…the camera pinnace, hovering a prudent fifty miles away, zoomed in to the limit of its magnification, and the hoop became an enormous puffy doughnut, bumpy with outside structures, and the stick swelled to an immense cylindrical shaft…
Somewhere inside the long shaft, Chinese technicians bustled around a massive globate housing that bristled like a hedgehog with converging laser assemblies. Towering stacks of capacitors marched endlessly down the arched chamber. Pipes and cables disappeared through a thick bulkhead. On the other side of the bulkhead, a team of American technicians tended the dull buging shapes of of cryogenic storage vats and monitored a bewildering array of computer displays.
A walnut-size pellet of boron dropped into a vat. it was hollow on the inside, and beautifully machined, with twelve precise pinholes slanting through its jacket. It was immediately stuffed with a tiny snowball made of frozen deuterium and tritium
A computer on the American side of the bulkhead positioned the pellet to within an angstrom and fired it through a long pipe into the chamber of the Chinese device. All the lasers fired at once in a burst that lasted only a few picoseconds. They were computer controlled by a single oscillator on the American side…
Time out for a minute.
Back in the mid seventies, when The Jupiter Theft was being written, laser induced fusion via inertial confinement was looked on very hopefully. It was seen as a possible solution to the very difficult problems encountered by magnetic confinement devices. Subsequent experience proved it to have problems of its own.
Back in 1984, T.A. Heppenheimer wrote a quite good history of fusion research aimed at the lay audience. It was titled Man-Made Sun, and I think it holds up rather well, even today, for the curious and non-technical reader.
He covers the history of magnetic confinement fusion, inertial confinement fusion, a handful of more speculative concepts, and concludes with some tempting prospects for the future. I first learned of Farnsworth Fusors from this book.
Interestingly, he even gives a pretty fair accounting of Robert Bussard’s Amazing Riggatron Fusion adventure with Bob Guccione. Mind you, I haven’t opened my copy in over fifteen years, so caveat whatever.
I’d have to say that my one favorite line from the book was a heartfelt quote from a magnetic machine advocate. “Those laser guys are such liars!”
We now return to the launch…
Twelve thread-thin beams of coherent light blasted through the pellets pinholes and converged at the center of the snowball. A tiny volume of space turned into hell. A few cubic microns of hydrogen isotopes became ten times hotter than the interior of the sun. The fusion reaction became self-sustaining. The pressure of the blast crushed superheated plasma to the awesome density of degenerate matter, and held the pellet together for the few picoseconds needed to initiate the next stage of the reaction.
For hydrogen fusion, a mere 200 million degrees Fahrenheit had been sufficient. For boron fission, a temperature in the billions of degrees was needed. Fusion was only the trigger. The raging nuclear fury in that tortured speck of matter stripped hot protons from surrounding hydrogen atoms and drove them with incredible energy into the now-collapsing nuclei of boron-11 atoms. The extra proton was too much for the boron nucleus to hold. Each atom split into three helium nuclei. The energy released was tremendous–far more than the controlled fusion energy that mankind had unlocked a half century before. a stream of electrically charged helium nuclei sought their mad escape rearward through the ship’s nozzles.
The ship trembled and moved.
Another pellet dropped. Another chamber turned into hell. Then, three seconds later, another. And another,
The ship, shuddering, picked up speed. It was accelerating rapidly now, at one percent of a g.
One hundredth of a gee? Now that’s what I call high performance, and I’m not being the slightest bit facetious. One hundredth of a gee will take you anywhere in the solar system if you can keep the engines running long enough.
You could reach Mars in weeks instead of the months currently envisioned. Jupiter in months instead of years. With constant boost, you’d reach Pluto in less than a year instead of the decades current technology requires. That’s what a hundredth of a gee will get you. Of course, it would be nice if we could do better.
Boron fusion might someday deliver that kind of performance. As far as I know, this is the very first depiction of it in the annals of science fiction. I’m sure I’ll hear about it if I’m mistaken.