|The Petawatt laser's compression chamber is the size of a school bus and, to handle the laser's high power, its diffraction gratings--the world's largest--are about a meter across (see right-hand hoop). Photocredit: Bryan Quintard/LLNL|
When Bruno Bauer inherited Zebra, a retired 2-trillion-watt pulsed-power machine from Los Alamos National Laboratory, he used it to found the Nevada Terawatt Facility in Stead, 15 kilometers from the Reno campus of the University of Nevada, where he is a professor. Now the NTF is on the verge of getting an even rarer castoff: the world's most powerful laser, the Petawatt, from LANL's sister Department of Energy (DOE) weapons lab in Livermore, California.
Completed in 1996, the Petawatt was dismantled three years later when the multibeam Nova laser, off which it fed, was shut down so that time and expertise could be concentrated on the controversial National Ignition Facility (NIF). While the Petawatt was running, researchers found they could do science with the 1021 W/cm2 laser that they hadn't anticipated, including creating antimatter, relativistic electrons, and proton beams previously possible only with particle accelerators (see Physics Today, January 1998, page 22*). The Petawatt laser opened the door to fast-ignition fusion, new ways to probe material structure and behavior, and modeling of astrophysical phenomena in the lab. Similar short-pulse, high-intensity projects are under way in France, Germany, the UK, and Japan.
"Livermore would dearly love to retain and operate their Petawatt. They blazed the trail, and they know the wonderful physics opportunities associated with the device," says Bob Perret, a Livermore weapons scientist and adviser to DOE activities in Nevada. But, he adds, "having access to a petawatt in Nevada is better than no access at all."
As part of the NTF, the Petawatt will be open to the wider user community. Bauer and his colleagues plan to use it for fusion energy, plasma, atomic physics, environmental, and materials science studies, as well as in research for stockpile stewardship — DOE's experimental and computational program for safeguarding US nuclear capability.
Bauer landed both Zebra and the Petawatt laser through personal contacts, but moving the Petawatt also has strong political support. Congress has directed DOE to help the NTF team set it up, and Nevada Senator Harry Reid secured $2.5 million in the 2001 Energy and Water Appropriations bill for moving it to his state.
Resurrecting the Petawatt is expected to cost at least $7.5 million (building on Nova, Livermore originally spent $10 million; from scratch, estimates put the cost at about $30 million). The NTF team is designing and building, among other things, a laser configuration from old and new parts, a clean room, and a frame for the laser. The plan is to build up to petawatt capacity in steps over three years.
Not everybody gets giant castoff lasers, but scrounging for used scientific equipment is common. Resourceful experimenters dig up everything from solar panels to synchrotron sources. They find equipment in university and national labs, in private companies, and through commercial surplus vendors. In addition to any costs, the recipient covers shipping.
"The way you get a new program started is to do some fraction of the work before it's funded," says Jefferson Lab's Fred Dylla. "How do you do that? You either recycle old equipment, or you borrow it, or you find it cheap. You look for equipment you might be able to scrounge, locally through universities, through your network of friends. A good scientist should be constantly on the lookout."
"My lab is built largely of pieces of found equipment," says David Grier, a condensed matter physicist at the University of Chicago. He has picked up, for example, glass liquid helium dewars at Argonne National Laboratory. "They had a huge stock of them, and no one was using them. We snarfed them. Wherever I happen to find myself, if I see something I'll ask about it. There's always stuff in the hallways that is nominally broken."
The best stuff to scrounge, the initiated agree, has longevity — magnets, steel, cables, pumps. Says Ed Morse, a nuclear engineer at the University of California, Berkeley, "If you get a 100-kV power supply built in 1950, chances are you'll be happy. There is continual improvement, but no quantum leaps. Computers are the most useless — they are right up there with disposable diapers in landfill."
In the early 1990s, when Berkeley took out its reactor, Morse grabbed the spot for the RTNS-1, a 1960s-era rotating target neutron source he wangled from Livermore. "The controls were out of a sci-fi film, with lucite rods as switches. We got rid of all that and put in plastic fiber optics. We were able to bring it into the computer age."
Morse's machine fuses deuterium and tritium, producing 14-MeV neutrons. He uses it for NIF-related and fusion energy research, and to study neutron interactions with rocks and other materials to help detect clandestine detonations of hydrogen bombs, which also produce 14-MeV neutrons.
|Scrounged phototubes being installed in the MiniBooNE neutrino detector at Fermilab this past spring by project member Peter Meyers of Princeton University. Photocredit: Reider Hahn/Fermilab visual media services|
Morse's collection of scrounged material also includes a 20-MW radar transmitter from a US military base on the Kwajalein atoll near New Guinea. "I brought back five radar tubes, 16 feet long and 3800 pounds each--we called them Buicks. They were used to drive a big radar antenna," says Morse, who put them to work heating plasma. "Getting old radar gear is one of the oldest tricks in the book. The cold war was a peak in the American experience in terms of hardware."
"Every experiment I have been on has had a substantial amount of scrounged equipment," adds Columbia University physicist Janet Conrad, who works on the MiniBooNE neutrino detector. MiniBooNE's recycled booty includes 1300 phototubes and electronics from LANL, 1000 tons of steel blocks from Oak Ridge National Laboratory, and magnets from Fermilab and CERN. "About half of the equipment on MiniBooNE is surplus, but this is extreme. My guess is that most small high-energy physics experiments have about 10% scrounged material," says Conrad.
The big labs have a tradition of sharing equipment. "Lots of people have their eyes on LEP's old RF [radio frequency] cavities," says Peter Limon of Fermilab, which has already acquired magnets from the Large Electron-Positron collider at CERN. Then there is the Scrounge-atron. Part of DOE's stockpile stewardship program, the accelerator would be used to study the dynamics of explosions with 30-GeV protons. "We are trying to find the least expensive way to do things, and also the fastest," says Ed Hartouni, the Livermore scientist who thought up the Scrounge-atron. So far, Hartouni and colleagues have scrounged 120 magnets and assorted accelerator parts from Fermilab's defunct Main Ring. In exchange, Fermilab got steel blocks that — in their third experimental life — will be used as radiation shielding for producing neutrinos that zip 730 kilometers to the Soudan mine in Minnesota for the Main Injector Neutrino Oscillation experiment.
Industry is another good source for hand-me-down equipment. When Mool Gupta left a 17-year career at Kodak in 1998 to start the Applied Research Center at Old Dominion University in Norfolk, Virginia, he came away loaded with lab equipment. His connections also garnered Old Dominion a used molecular beam epitaxy system (worth $1 million new) from Xerox and $40 000 in machine-shop tools from a local company. "You always find out about things through contacts," says Gupta. "But you need to justify the need for the equipment, show it will have a good home. The third thing is that we tie our research to the donor. We owe them, so we do joint research."
And, according to the January 2001 issue of Semiconductor International, an online monthly publication, the IBM Corp is donating a superconducting synchrotron source that it used for x-ray lithography to Jefferson Lab. The donor and recipient have a secrecy agreement, however, and declined to discuss the gift.
Government agencies offer surplus equipment first to people on the same site. Then to anyone in the same agency. Next it's opened up to all government agencies. Whatever remains is made available to nonprofit organizations, such as universities and hospitals. The leftovers are offered to state and local governments, which auction some of them to the public.
|The cables first used in the 1977 experiment in which the bottom quark was discovered have been repeatedly recycled by Fermilab scientists. Photocredit: Reider Hahn/Fermilab visual media services|
Those formal procedures mean that researchers coveting castoffs from the government do well to find shortcuts. "We all kind of know what's at various labs," says Gerry Navratil, a plasma physicist at Columbia University. "If you hear that an experiment is closing, you inquire. If you had a close working collaboration, you would find out first and get preferential access." One way around official disposal regulations is to get equipment on loan; often the title is transferred a few years later. Companies, on the other hand, are free to sell or give away their equipment.
"I have gotten tons of DOD [Department of Defense] stuff on the surplus market," says Phil Lubin, an experimental cosmologist at the University of California, Santa Barbara. "There is much more floating around. The problem is that the people who need it don't know who has it." A couple of years ago, Lubin wanted to build lightweight carbon composite mirrors for balloon-borne measurements of the cosmic microwave background radiation. "New, they would have cost 20 times what we could afford," he says. Through hard-core detective work, Lubin tracked down graphite molds from the DOD and carbon fiber material that NASA had used in readying the Chandra X-Ray Observatory for launch. The molds were recut, says Lubin, "and we ended up with incredibly good mirrors."
"Scrounging has been a significant part of our ability to do science," Lubin adds. "It takes time and effort and perseverance. I don't particularly enjoy it. I wouldn't do it if I had an infinite flow of money."
Ray Fonck of the University of Wisconsin-Madison leaned heavily on scrounged equipment to build a spherical tokamak. "I had a tremendous advantage because of my earlier career at Princeton Plasma Physics Laboratory, so I have contacts and friends there. In our case, it is not a matter of just saving money. It is a matter of whether the program would exist at all."
Fonck has help with scrounging: His institution is one of the few places that actually pays someone to scout for stuff. Dale Schutte scans federal and state surplus equipment Web sites and keeps track of what researchers want. "Sometimes they give me specific items to look for, sometimes we get a random lead," says Schutte. "We get a lot of test equipment — capacitors, chillers, microwave equipment, oscilloscopes ... We got 300 capacitors last month that were left over from Star Wars days. We will use them to build pulse-forming networks to power large klystron tubes." Schutte works for one of Wisconsin's fusion groups but, he says, "I am trying to motivate other physics and engineering research groups to use the various surplus programs on a more regular basis."
And scientists may find that it's become simpler to scrounge from LANL. Since spring 2000, the lab has accepted requests for specific items, rather than periodically posting lists. "We've streamlined the process, and the recipient is transferred title," says Joe Roybal, one of the lab's property managers. "We gave away about $1 million worth of stuff our first year." (To submit requests to LANL's Laboratory Education Equipment Gift program, e-mail email@example.com.)
But scrounging does have drawbacks. "The trick," says Conrad, "is to know when the scrounged equipment will help you — you can waste a lot of time and energy pushing round pegs into square holes. Also, the equipment may not be in the as-advertised condition. Never accept anything sight unseen." Adds Navratil, "It's rare that you can take and use something the way it was used before. There is nothing worse than compromising your scientific objectives because a machine is the only thing you could get. That's false economy."
Complications can also arise when the government retains ownership. "Prior approval is required before we can lend or cannibalize," says Schutte. And tracking government property can be a nuisance. Says Morse, "One of my cryopumps belongs to the government and is labeled a proliferation risk. So every year when we get audited, I say, 'Skip the first three, but that fourth one is our proliferation cryopump.' "
There is broad agreement that the key to successful scrounging is personal connections. It also helps to have "no sense of shame," says Conrad. "You should always ask. The worst that they can tell you is 'No.' "
Submitted: Saturday, June 30, 2001 - 11:00pm