The Cutting Edge: Computing / Technology / Innovation : PLOWSHARES : Nuclear Fusion’s New Die-Hard Applications

Artificial knee joints that last a lifetime . . . automotive bearings that never wear out . . . industrial machinery with surfaces so hard they’re almost immune to damage.

Wishful thinking? Scientists at the Los Alamos National Laboratory, the University of Wisconsin and General Motors think not.

Using a particle accelerator first built for the New Mexico lab’s effort to develop small magnetic fusion reactors for space, the three organizations are trying to develop large-scale applications for a process known as ion implantation. Nuclear engineer John Conrad of the University of Wisconsin invented the process a decade ago, but until recently it was applicable only to very small items, such as ball bearings.

Conrad is working with the lab and GM under a $14-million program to revamp ion implantation to industrial applications. The large accelerator at Los Alamos is being used to see if equipment weighing several tons can be treated with the process.

Ion implantation is not just another way of coating a piece of equipment. It alters the outer layer in such a way that it produces an incredibly hard surface.

The target is placed inside the accelerator’s vacuum chamber, and the chamber is flooded with gas at low pressure. Oscillating radio waves strip the gas atoms of electrons, producing positively charged particles, or ions. Short pulses of negative charges are applied to the target, attracting the ions like a huge magnet.

The ions strike the target with such force that they bury themselves in the surface of the target, physically and chemically transforming the outer thousandth of an inch into a much harder material. That could extend an object’s life span as much as a hundredfold, researchers believe.