Experimental Facilities: End Station A (ESA)
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When the SLAC linac was completed in 1966 it only accelerated electrons. Other experiments took place in the second large building known as End Station B, where a large bubble chamber detector was used. |
Today's view of the research yard, looking toward the west. |
This technology for detectors involved visual scanning of each event photograph for interesting pictures and is no longer used today. Photographic and visual methods have been replaced by electronic data recording and computer analysis.
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During the period from 1966 to 1972 the physics research program at SLAC was based solely on fixed-target experiments carried out with the two-mile linac. Early SLAC experiments were the first to show that the constituents of the atomic nucleus, the proton and neutron, are themselves composed of smaller, more fundamental objects called quarks. This work was recognized by awarding the 1990 Nobel Prize in Physics to Jerome Friedman and Henry Kendall of MIT and Richard Taylor of SLAC. |
Sources of polarized beam, in which the electrons' magnetic fields are aligned along the beam axis, were added to the SLAC linac in the 1970s. In 1978 the polarized electron beam was used in an experiment of exceptionally high precision that established a clear relationship between the familiar electromagnetic force and the so-called weak force that produces radioactive decay.
Work continues on a series of experiments exploiting the polarized beams with targets whose atoms are also polarized to produce a deeper understanding of the structure of the proton and neutron and their quark constituents. Experiments with other targets are aimed at understanding the behavior of quarks in the nuclei of heavy atoms.
