The Linear Super-Collider
from The Last Tomorrow

The Linear Super-Collider (LSC) is a high energy particle collider a thousand times more powerful than the Large Hadron Collider at CERN. If it were built as counter-rotating beams in a circle, it would have to be roughly the size of the Earth for superconducting magnets to bend the particles into a circle. Imagine a particle accelerator built along the entire equator!

At such high energies, it must lie in a straight line. And the particles can't be accelerated by microwaves a little at a time, but rather must be quickly boosted in a single pass. Luckily, there is a relatively new accelerator technology that makes this possible: a laser wakefield accelerator. These are used today to build desktop particle accelerators. The implementation is simple: an extremely brief, extremely high-energy laser pulse strikes a plate depositing its energy into a thin layer of atoms. They become highly ionized, and the freed electrons, being light weight, zip quickly away. In the meantime, the relatively positively charged nuclei move much more slowly and an enormous electric field results. In today's desktop accelerators, laser wakefield accelerators routinely produce Giga-Electron-Volt (GEV) particles in less than a centimeter.

For The Last Tomorrow, the technology must be improved. Particles already racing along at nearly the speed of light pass through a tiny hole in a plate, just as a laser pulse strikes a carefully shaped cone around the hole. The process is repeated every centimeter, each adding 12 GEV of energy per proton to the beam passing through. And in a five kilometer accelerator this happens 500,000 times resulting in six-million-GEV (per proton) particles (that's six thousand Tera Electron-Volts (6,000 TEVs), or six Peta Electron Volts (6 PEV), per proton, per beam). There are two of these beams in a collider - the beams cross in the middle of the 10-kilometer collider. And the collision energy of plutonium nuclei (92 protons) is thus approximately 1,200 PEV - a thousand times greater than that achieved by the LHC (which collides lead nuclei at 1,150 TEV). All kinds of interesting physics are bound to occur at these energies.

In The Last Tomorrow, the collision results in a phase change in the universe, equivalent to when a solid melts to a liquid, or when a supercooled liquid suddenly crystallizes. It's already happened somewhere in the universe, of course, but is propagating toward us only at the speed of light, so hopefully we have a billion or two years before some other civilization's experiment destroys us.

See this description of the tunnel containing the collider.

The Linear Super-Collider from The Last Tomorrow

The Linear Super-Collider
from The Last Tomorrow