If all had gone according to plan, the gargantuan U.S. high-energy physics project would have already found the Higgs particle, having solidly won the competition with its European competitor. Peter Higgs, in fact, might have collected his physics Nobel a few years earlier.
The Superconducting Super Collider (SSC) that would have graced the rolling prairies of Texas would have boasted energy 20 times larger than any accelerator ever constructed and might have been revealing whatever surprises that lay beyond the Higgs, allowing the U.S. to retain dominance in high-energy physics. Except the story didn’t play out according to script. Twenty years ago, on October 21, 1993, Congress officially killed the project, leaving behind more than vacant tunnel in the Texas earth.
Since then, the glory of particle physics has moved to Europe. Last year the Large Hadron Collider (LHC) at the CERN laboratory in Geneva, Switzerland,discovered the Higgs, the biggest event in physics in a generation, and, adding insult to injury, announced it on a U.S. national holiday: the Fourth of July.
What went wrong with the SSC, in a nation then usually admired for its can-do attitude? What lessons were learned to apply to future efforts? And what has been the impact on U.S. physics since the spotlight moved to Europe?
Although no one reason explains the cancellation, a few key aspects of the project stand out. The inability to secure any foreign sources of funding was pivotal, especially as the project’s cost increased by a factor of three from initial estimates amid a national recession and political insistence on controlling government spending. The project’s scale was 20 times bigger than anything physicists had ever managed before, and cultural differences between the scientific side of the accelerator’s management and the military-industrial culture imposed by the U.S. Department of Energy (DoE) led to conflicts, seemingly endless audits and an overall lack of trust.
An accelerator that would collide high-energy protons, the SSC’s ring was to be 87.1 kilometers in circumference, circling the small town of Waxahachie, Tex., 48 kilometers south of Dallas. At 20 tera-electron volts (TeV, or trillion electron volts) per proton—close to the regime of ultrahigh-energy cosmic rays—it was to have 20 times the collision energy of any existing or planned machine; it would have had five times the energy of even today’s LHC collisions. That design had only one tenth the beam luminosity of the LHC, but because of its higher energy, it would have produced about half the Higgs events seen at CERN, says John Gunion of the University of California, Davis, enough to have found the Higgs and with the higher energy necessary to detect what, if anything, lies past the Higgs energy, such as supersymmetric or dark matter constituents.
When canceled, about 20 percent of the SSC was complete—specifically, two dozen kilometers of tunnel had been drilled with 17 access shafts, and 18,600 square meters of buildings erected. Over $2 billion had already been spent, mostly by the DoE, but also $400 million by the state of Texas.
At its end the project was already employing 2,000 people at the site or in Dallas, about 200 of whom were scientists, plus a contingent of Russian physicists employed after the end of the Cold War. Another 13,000 jobs linked to the project never materialized. About half the SSC scientists left the field of physics, according to a 1994 survey by Science magazine, some to become analysts in the financial industry. Many took a loss on homes sold in a sudden buyer’s market.
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