John Seeman, head of accelerator systems at SLAC, said half a dozen labs have requested components of the PEP-II collider, which created particles called B mesons for studying the disappearance of antimatter after the big bang. The Frascati National Laboratory in Italy is a major contender. Researchers there have proposed a more powerful version of the PEP-II experiment to the Italian government and could use almost all the PEP-II's equipment, Seeman says. Fermilab has also requested some of PEP-II's magnets for a new machine that would make high-energy proton beams for neutrino research. (When energized protons crash into beryllium targets, they create short-lived pions that decay into neutrinos.)
Fermilab intends to reuse most of the Tevatron's parts for making neutrinos, including a booster accelerator that prepared protons for entry into the main Tevatron ring, which measures 3.9 miles (6.3 kilometers) in circumference. Fermilab's deputy director, Young Kee Kim, says that the lab wants to keep the main ring in working order in hopes of reusing it for future experiments.
For the SSC, particle research was never in the stars. The state of Texas auctioned off the linear accelerator equipment in 1996 to a Denton, Tex.–based company for the bargain price of $5 million—the book value for the unused parts was over $20 million, Courtney says. Trace Life Sciences inherited the accelerator when it acquired that company in 2003.
Trace now uses the linac to accelerate a beam of protons to 32.8-mega-electron volts (3.28 million eV) and bombard up to five different targets simultaneously for different isotopes. Bombarding thallium with protons at 29 mega-electron volts (MeV) yields the isotope lead 201, which decays to form thallium 201—used in diagnosing myocardial infarctions, or heart attacks. Iodine 123 and copper 64 are used for medical imaging such as in PET scans. Graphite pieces placed in front of the 32.8 MeV beam slow the protons to the energies required for different isotopes.
The company hopes to bring online two additional accelerator stages—designed to boost protons to 50- and 70-MeV—that were not stored properly after the SSC shut down and fell into disrepair. Trace might then begin providing specialty medical isotopes such as strontium 82 and iron 52, both used in PET scans, which are currently available only from government labs.
There are advantages to working with scavenged parts from a futuristic particle accelerator that at its peak employed thousands of workers. For one thing, customer service is a breeze. When Courtney needs technical advice, all he has to do is call one of the national labs, he says, where researchers who worked on the parts are happy to offer their services.