LIKE a man hoping to find a second-hand sports car at a knockdown price, used to regularly peruse the for-sale ads in Commerce Business Daily. Then one day in 1995, Morgan saw exactly what he had been looking for and submitted a bid. Three weeks later, Morgan and his company were the proud owners of parts from the world鈥檚 biggest atom smasher for the princely sum of $4.5 million.
Morgan had bought part of the defunct , a behemoth of a machine designed to search for the much vaunted Higgs boson, aka the God particle, which is supposed to give all other particles their mass. When funding for the 87-kilometre-round SSC was slashed in 1993 a cool $2 billion had already been spent. Now the huge tunnels in Waxahachie, Texas, sat dark and empty. Since the parts for the accelerator had never actually been assembled into a working machine, they sat crated up in a warehouse, awaiting their new owner and their new destiny.
The tale of the SSC illustrates what can happen to big physics projects when the funding dries up. When a particle accelerator reaches the end of the road, the physicists hold a wake for the machine鈥檚 death. Then the electromagnets are powered down, the cryogenic liquids are drained and the lights are turned off. That much is certain. What happens next, though, is not.
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News of a project鈥檚 death travels, and soon scientists around the planet are competing for the chance to acquire some serious hardware. A hospital may need particle beams for cancer treatment, say. There are also commercial uses for power supplies. Out of odd parts, whimsical scientists can construct works of art. And particle accelerators, with their beam-bending magnets, are mother lodes of iron and copper. The car you drive may contain steel that in another life formed the core of a cyclotron. With commodity prices soaring and serious amounts of valuable metals in big physics projects, some machines and experiments may be worth more now than when they were built (see chart). Could selling them to others lead to even bigger machines and more profound discoveries?
A few months after Morgan secured the deal, a team of experts from International Isotopes descended on the warehouse where the SSC parts were stockpiled to find out exactly what they had got for their money. 鈥淲e spent a long, hot summer in Waxahachie going through stuff,鈥� says Bill Courtney, who manages the accelerator. He and others looked at each piece of equipment and decided whether it was essential for their purpose or could be resold.
Then there was the problem of where to store the mountain of parts and how to get them there. The SSC would have been a chain of machines that accelerated protons to increasingly higher energies. International Isotopes bought the first link in the chain, a machine called a linear accelerator or linac. A metal pipe 100 metres long, the linac consisted of four sections of speed-boosting drift tubes, a high-powered vacuum system to suck out all the air, and bundles of electromagnets to steer the protons.
Soon 50 trailers were rumbling out of Waxahachie. Large items found temporary housing in a vacant furniture store in a suburb of Fort Worth. Smaller pieces were trucked 95 kilometres north across Dallas to the accelerator鈥檚 eventual destination: the town of Denton.
International Isotopes planned to produce radioisotopes such as iodine-123 to help diagnose cancer and identify damaged heart and lung tissue. But assembling the linac and converting it for commercial use was a mammoth task. Qualified staff had to be hired, land acquired, and a facility built.
The team made fundamental changes to the accelerator, which had been designed to stream just 10 pulses of negative hydrogen ions a second, for 1 hour a day. 鈥淚t was meant to provide an extremely high quality beam,鈥� Courtney says. For industrial purposes, however, they needed a heavy-duty ion cannon to pump out 40 times as many ions as the SSC would have required.
Today the linac, now operated by Trace Life Sciences, runs 24 hours a day, emitting a continual beam of positive hydrogen ions, or protons, which are then accelerated to higher energies. A 鈥渒icker鈥� magnet directs portions of the proton beam towards five different targets. These are made of elements such as thallium electroplated onto copper plates. Technicians later dissolve away the newly radioactive material and package it in vials, which are shipped by FedEx in lead-lined styrofoam containers.
The SSC is not alone. Recent years have seen the sun set on several giant physics experiments. The HERA in Hamburg, Germany, shut off power last June. And in April, budget cuts in the US meant the collider at the in California had to close, along with its detector .
While Trace Life Sciences doesn鈥檛 want any equipment from these projects, it is interested in scientific expertise. 鈥淲e do have an eye on key staff,鈥� says Darren Brown, the company鈥檚 chief executive officer.
Others would like to get their hands on the machinery. Physicists in Italy are hoping parts from PEP-II will help to get a project called SuperB off the drawing board. The plan is for SuperB to sit in a tunnel deep beneath the ruins of a villa at the University of Rome Tor Vergata where it will smash electrons and positrons head on to create sprays of B mesons, just as PEP-II did. B mesons could provide important clues to the subtle differences between matter and antimatter.
By combining parts from PEP-II with some new technology, SuperB will churn out particles 100 times as fast as the old collider did. John Seeman, head of accelerator systems at SLAC, estimates that if the US Department of Energy approves the transfer, the Italians will need 500 shipping containers to take their booty home. 鈥淭hey want 90 per cent of the magnets, the radiofrequency system and most of the power supplies,鈥� Seeman says. A group at Stanford University in California will reuse the remaining magnets to build a in the PEP-II tunnel.
There is another option, though. As the economy has gone bust, commodity markets have boomed. With scrap metal at a premium, thieves have taken note, stealing lead from church roofs and cutting up bronze statues. In July 2008, The New York Times reported that the in Philadelphia had left many streets dotted with death traps for unwary pedestrians.
So what would a scrap merchant make of PEP-II? The PEP-II tunnel houses two separate rings for the electrons and positrons, each with a circumference of 2.2 kilometres. The particle beams were steered by 1900 powerful electromagnets made of steel cores surrounded by copper or aluminium windings.
All told, there are 4200 tonnes of steel, 448 tonnes of copper and 135 tonnes of aluminium tied up inside the PEP-II electromagnets. Their total scrap value is a cool $2.5 million, according to Bob Garino at the in Washington DC.
There is gold too, although it wouldn鈥檛 be worth your time to scrape it off the components it coats, Seeman says. 鈥淵ou鈥檇 get less than a wedding ring鈥檚 worth.鈥�
And that鈥檚 just the storage rings. As the two beams enter the BaBar , they run a gauntlet of four huge permanent magnets made of sintered cobalt-samarium. These steer the electron and positron beams into and out of the head-on collision zone.
Money magnets
Weighing about a tonne each, they are probably worth at least $300,000 apiece. But the resale value is zero, because they cannot be turned off and there is no easy way to break them down, says Kim Johnston of Master Magnetics, an industrial magnet manufacturer in Castle Rock, Colorado. 鈥淭hey鈥檙e too dangerous,鈥� he adds. 鈥淵ou could get impaled if you had a screwdriver in your pocket.鈥� The magnets鈥� fate remains uncertain. Despite their strength, the permanent magnets are out-muscled by BaBar鈥檚 superconducting magnet, a coil of niobium and titanium embedded in aluminium that wraps around the detector鈥檚 core like a python. The scrap value of the niobium: $47,000.
The superconductor鈥檚 field skews the paths of charged subatomic debris from the collisions into characteristic spirals that betray the nature of the particles. Some of those particles whiz into a concentric shell surrounding the collision zone that contains a premium component: 25 tonnes of high-purity caesium iodide crystals.
The crystals, a beefed-up relative of table salt, emit twinkles of light as charged particles whiz through. There are about 6500 crystals, each 25 centimetres long and weighing 4 kilograms. 鈥淣ot spectacularly cheap,鈥� says BaBar鈥檚 technical coordinator Bill Wisniewski, noting that SLAC originally paid $3 per cubic centimetre, totalling $20 million.
Today the crystals might be worth up to $125 million, according to company Sigma Aldrich, which supplies and manufactures materials for scientific experiments. The price rise stems from the 9/11 terrorist attacks, when the US made it a priority to keep radioactive material from entering its ports. Caesium iodide is a key component of 鈥減ortal monitors鈥� 鈥� walk- or drive-through scanners that detect radioactive items. If the caesium iodide crystals in Babar were a more useful shape, then other people could use them, says Peter Waer of Radiation Monitoring Devices in Watertown, Massachusetts. BaBar鈥檚 crystals are so plentiful that a manufacturer might decide to design a portal monitor around them, rather than dissolving and recrystallising the salt, he says.
BaBar also contains 1000 tonnes of steel cladding, bolstered by 100 tonnes of brass, worth $430,000 and $350,000 respectively. The metal sandwiches more detectors and also serves as a radiation shield. 鈥淎s far as we know, it鈥檚 not radioactive,鈥� Wisniewski says. 杏吧原创s have taken chunks of steel out during refitting stints and not measured any activity.
PEP-II and BaBar, it would seem, are a scrap dealer鈥檚 paradise. So should the custodians of particle accelerators be worried about an onslaught of ruffians armed with oxyacetylene torches?
鈥淥ld accelerators might seem a scrap dealer鈥檚 paradise. Should lab owners be worried about ruffians armed with oxyacetylene torches?鈥�
Anyone trying to fence metal carved from accelerator magnets might run into something less forgiving than the site鈥檚 resident Dobermann (see 鈥淗ot or not?鈥�). Because steel mills have a horror of contaminating tonnes of metal with a small amount of radioactive isotope, each salvage yard has its own portal monitor that sounds an alarm for 鈥渁ctivated鈥� scrap. 鈥淭he last thing we want is something that sets off the detector,鈥� says Garino. 鈥淢ills themselves are sick to death of that stuff.鈥�
It gets worse for those who would recycle American accelerators. On 13 September 2000, the US Department of Energy announced a moratorium on the commercial resale of any metal that, from that day forward, spent time in the neighbourhood of a particle accelerator, regardless of its radioactivity.
Among the government laboratories, though, parts and instruments may be freely exchanged. The neutrino experiment at in Batavia, Illinois, was built almost entirely from recycled parts, with some from Japan and some from France. Frugality saved the scientists $3.3 million.
Reusing junk does come with certain hazards, though. 鈥淪ome of the students were pulling apart a rat鈥檚 nest of old cables,鈥� says SciBoone鈥檚 spokesperson Morgan Wascko, 鈥渁nd a rat actually came out and ran off.鈥� After that, they checked the cables for bite marks to make sure they had not been damaged.
Other countries do not have such draconian restrictions on accelerator scrap. When the experiment was dismantled after the HERA accelerator shut down, the particle physics laboratory in Hamburg was free to sell any material that cleared Germany鈥檚 radiation regulations. This included 50 tonnes of cables, 100 tonnes of steel, and 70 tonnes of aluminium, says Uwe Schneekloth, ZEUS鈥檚 technical coordinator.
鈥淲e tried to reuse all the components that could be reused,鈥� he says, 鈥渂ut one has to keep in mind that every detector is individual. Most components were specifically designed and have no further use.鈥� Several ZEUS parts will eventually become museum exhibits.
How do those who assembled these giant machines to probe the innermost mysteries of the cosmos feel when they see their work torn apart for scrap? Kurt Krueger, a technician at in California, is a veteran of these experiments and most recently helped to install the detector at CERN鈥檚 near Geneva, Switzerland. 鈥淵ou can鈥檛 think that way,鈥� Krueger says. 鈥淵ou have to think about what they achieved with the parts you built.鈥�
Hot or not?
Wayne Wood, the environmental safety officer at McGill University in Montreal, Canada, knows something about taking an accelerator apart. In 1993, his supervisor asked him to oversee the dismantling of McGill鈥檚 cyclotron, built in 1945.
The university needed the space. 鈥淚n downtown Montreal the real estate is too valuable,鈥� Wood says. His task involved removing 500 tonnes of iron and copper, and the enclosing concrete vault, from the Foster Radiation Laboratory. 鈥淎nd separating parts that were hot from those that were not.鈥�
As it turned out, the concrete and most of the metal was not radioactive. But at the start Wood didn鈥檛 know that. He hired external consultants to monitor the operation. 鈥淭hey were having trouble zeroing their meters the first week,鈥� Wood says. The reason, they found, was buried under the threshold to the room: a steel box crammed with radioactive isotopes from ancient experiments.
Wood sent the parts that were hot to Canada鈥檚 only nuclear waste facility at Chalk River, Ontario. Those that were not 鈥� the copper windings and steel plates 鈥� he sold for scrap. From these he raised $25,000, enough to pay the consultants鈥� fee. The electromagnet itself, 275 tonnes of iron, was another matter. A dedicated welder sat on the magnet for six weeks cutting it up into chunks. The scrap iron was his reward, to the tune of around $31,000.
