Introduction Introduction Introduction
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The experimental apparatus at accelerator facilities that physicists use to study particles are called detectors. The detector/accelerator system can be thought of as enormous microscopes, so powerful that they can probe within the tiny atomic nucleus and make fundamental particle activity visible to us.

Feynman looking at a microscope image Just as Rutherford used zinc sulfide to test for the presence of invisible alpha particles and used this knowledge to determine the path of alpha particles, modern physicists must find a way to get information about short-lived particles whose paths are too short to detect. To do this they look at the particles' decay products, which exist long enough to be detected.

To look for these various particles and decay products, physicists have designed multi-component detectors that test different aspects of an event. Each component of a modern detector is used for measuring particle energies and momenta, and/or distinguishing different particle types. When all these components work together to detect an event, individual particles can be singled out from the multitudes for analysis.

Following each event, computers collect and interpret the vast quantity of data from the detectors and present the extrapolated results to the physicist.