One of the next big experiments designed to illuminate the fundamental building blocks of matter should involve a 14-footwide magnet designed and road tested at the University of Illinois.
Scientists plan to hold protons, which are part of every atom, in the center of the magnet, bombard them with beams of electric particles and use the magnetic field to tell how the electrons bounce off.
UI physicist Doug Beck, the spokesman for the experiment, said the goal is to learn more about what's inside protons, which with neutrons make up 99 percent of the mass in the universe.
"We know less about how this 99 percent of the matter works than what you might think," Beck said.
Beck characterized the magnet experiment, dubbed g0 or gee zero, as a "tricky" way of getting a look inside the proton, which scientists believe is mostly composed of energy and of even lighter particles called quarks.
He compared bouncing the electrons off the protons to shooting a visible rack of pool balls and watching how the cue ball bounces off the figure out the rack's shape.
"We're trying to find out what form this energy is in," Beck said. "We know what the building blocks are, sort of. We just don't know how it's put together."
The project-now involving 100 people from the United States, Armenia, Canada and France-actually began to take shape more than a decade ago with Beck and some colleagues chatting about how they might "see" the energy in the proton.
They started designing in December 1990, and the contract for the giant magnet, the largest built in this country in several years, was awarded 3 and a half years ago.
Retired UI physicist Ron Laszewski designed the magnet, which cost $2.75 million to build. (The whole project will cost about $7.5 million, paid for by the National Science Foundation, the Energy Department and contributions from Canada and France.)
This is not the dime-store horseshoe magnet of your childhood. It's built around eight superconducting electromagnetic coils, cooled by liquid helium to 453 degrees below zero and operated by a computer. "It's intended to be set and forget," said Timothy Antaya of BWX Technologies, which built the magnet. "This thing will run for weeks, maybe months at a time."
Researchers supercool the magnet to eliminate resistance in the coils and yield a bigger magnetic field for less power.
"This way, the power bill is going to be very low compared to room temperature," said Steve Williamson,the UI physicist who serves as the experiment's coordinator.
The magnet arrived at the UI in December to be calibrated and field-tested before being installed at the Thomas Jefferson National Accelerator Facility in Virginia a year from now. Beck said the experiment will run off and on for five years.
Submitted: Sunday, February 18, 2001 - 12:00am