Questions and Answers

What kind of equipment do you work on?

Walking through the buildings and experimental areas at Jefferson Lab often reminds me of walking through a toy store - there is always something fun to see; whether it's the quarter-sized crystals from where the electron beam originates or the dinosaur-sized magnetic spectrometers that collect particles used to study the building blocks of matter.

For my college experiments (I am a student too!) I work with many people at the laboratory, building magnets and writing computer programs, learning how to answer questions about the electron beam. The equipment we use are tools which help us do our job, whether it is understanding the electron beam or studying the building blocks of the nucleus, quarks and gluons, and how they combine to form much of the universe.

Let me describe some of this equipment to you: Lasers are very common today (they are used in CD players or for entertainment shows) and at the laboratory, laser scientists shine carefully tuned laser beams, invisible to the human eye, onto crystal materials. This laser light helps produce the electrons which are used in the accelerator. Other scientists try to do just the opposite. At the Free Electron Laser facility, beams of electrons moving at almost the speed of light are actually wiggled back and forth with magnets (like those on your refrigerator, just MUCH more powerful and complicated looking) to produce intense beams of laser light to be used by scientists and companies. Computers and electronics are everywhere at the laboratory. More than 2,000 magnets in the accelerator along with thousands of other beam diagnostics are used to control the electron beam. Each is connected to electronics shelved in buildings. Two of these buildings have so many electronics they are longer than some trains. The electronics are connected by cables and wires totaling thousands of miles, most ultimately controlled by computers running many sophisticated programs.

As you can imagine, many people operate this equipment every day - while you are at school and while you are sleeping - because the accelerator runs 24 hours each day. I haven't even mentioned the world's largest helium refrigerator (turning helium gas like that in a carnival balloon into a liquid with a temperature hundreds of degrees below zero). This liquid helium is used to cool the superconducting accelerator cavities used to boost the electron beam toward the speed of light! One really big piece if equipment is called a spectrometer. It is used to collect particles that exist after the electron beam strikes the target of an experiment. By collecting particles produced when the collision occurs, the spectrometer provides a picture of how matter is put together. It is very much like a big, big microscope. However, the pictures are not like those you see in an optical microscope. Rather, spectrometers produce patterns of information which mathematics, physics, and good ideas help figure out.

Author:

Joe Grames, Polarized Source Group