The jury-rigged equipment is a testament to the resourcefulness of Collins's graduate students, the kind that only the command economies of communist Eastern Europe could have produced. A few of Collins's students picked up the X-ray machine from a dental-salvage business with a little sweet-talking and $1,500. Another student came up with the idea of using the 5-kilowatt amp to modulate the energy output.
The X-ray machine was left beaming on the hafnium for several weeks through a series of tests. There was no flash and bang -- even if hafnium proved to be everything Collins hoped it was, the microscopic sample's energy would be visible only to the most sensitive instruments. Instead, there was the painstaking recording and analysis of gamma-ray levels. Hafnium-178 has a half-life of 31 years, which means it gives off half of its stored energy over three decades. What Collins was looking for was clear evidence that his X-rays were accelerating that process, even a little bit.
Nothing about making the measurements or analyzing them was easy. It involved probability and margins of error, and required careful scientific rigor. But in a subsequent 1999 article in the respected scientific journal Physical Review Letters, Collins wrote that the experiment had been successful. The results were unambiguous, he claimed. He had been able to "trigger" the release of energy.
Among nuclear physicists, those results were met with some curiosity, some doubt and a great deal of ridicule. The results Collins claimed were absurdly out of whack with what conventional physics would allow for hafnium.
Critics also challenged his statistical accuracy, the high margin of error he reported and the overall significance of his results. Collins responded that the history of experimental physics was filled with examples of naysaying theoreticians being proved wrong. He dismissed the criticism as "judgmental opinion" and "logical fallacy."
But as the scientists fought out isomer triggering in the pages of Physical Review Letters, a number of dedicated isomer believers set out to show that Collins's results could be harnessed as a weapon. The isomer bomb began its roller-coaster ride from a controversial experiment in a relatively unknown science center to the inner sanctum of the military -- the E-Ring of the Pentagon. All it took was five years, an administration preoccupied with the war on terror, a new wellspring of support for nuclear and nuclear-type weapons, and an agency willing to ignore its own advisers.
Do You Believe In Isomers?
Based on Collins's reported success in the 1998 triggering, the Air Force moved in to support his work. Meanwhile, Pat McDaniel, an Air Force researcher who collaborated on the dental X-ray experiment, used his personal contacts to build interest at Sandia National Laboratories in New Mexico.
Sandia, along with Lawrence Livermore National Laboratory in California and Los Alamos National Laboratory in New Mexico, is operated by the Department of Energy. The labs make up the three legs of the U.S. nuclear weapons lab system. (As the "Z Division" of the Manhattan Project -- the super-secret World War II program to develop the atomic bomb -- Sandia was assigned the engineering task of designing and building the weapons, while Livermore and Los Alamos were at the heart of physics work.)
McDaniel found a receptive hearing from his friend and Sandia program manager Nancy Ries. Shortly after the 1998 experiment, Ries and McDaniel started handing out campaign-style buttons that read, "I believe in isomers," according to Peter Zimmerman, then a senior arms control official in the Clinton administration. Ries, McDaniel and intelligence officials began giving briefings touting isomer research as "the best thing for weapons research since sliced bread," Zimmerman said. Hafnium could be used to build a more powerful bomb or, more to the point of what the military was looking for, a small bomb with a huge bang, the believers argued. And even better, building a weapon using hafnium wouldn't violate internationally negotiated restrictions on testing nuclear weapons or congressional limits on developing new nuclear weapons. Because it wouldn't involve splitting atoms, a hafnium bomb would be a totally new class of weapon.
Zimmerman had long heard talk about isomers as a potent energy source for weapons, but had never taken it very seriously. He was well versed in the scientific issues -- with a PhD in nuclear physics. His 30-year career spanned the overlapping worlds of science and national security. The "I believe in isomers" campaign hit him just as he prepared to take over his new job in Foggy Bottom as chief scientist of the Arms Control and Disarmament Agency, whose mission was to both promote arms control and be on the lookout for new developments in weapons. As chief scientist, Zimmerman was responsible for preventing "technological surprise" in the weapons field. Though the science of an isomer bomb seemed to him to be questionable and the promises vastly unrealistic, he couldn't stop thinking about the 1939 decision by the Navy's research laboratory to ignore an Italian-born physicist, Enrico Fermi, who tried to convince the U.S. military that the fascists were working on a new weapon based on nuclear fission. The military thought he was talking science fiction.
Now, with talk of an isomer weapon, Zimmerman said recently, "I had the science fiction reaction, and a rather bad science fiction at that. But what I wanted to know was that if I discouraged DOD from funding it, I wouldn't be like the admiral who turned down Enrico Fermi in 1939."
Zimmerman had somewhere to turn: an elite, secretive group of senior scientists called the Jasons. Thought to be named after the Greek mythical hero Jason, the group of approximately 55 advisers has been around since 1959, most of the time as part of the Defense Advanced Research Proj-ects Agency (DARPA) -- the Pentagon's primary R&D arm. Operating mostly under the radar screen of public view, the Jasons pick their own members from among the nation's top scientists. Often called upon to evaluate controversies beyond the scientific understanding of government officials, the Jasons have weighed in on items ranging from obscure technology to weighty policy issues, and their influence over the years has been enormous. A 1966 report by the Jasons cast doubt on the use of strategic bombing to cut the Viet Cong's supply lines during the Vietnam War. In another report, the Jasons concluded that low-yield nuclear testing wasn't necessary for the United States to maintain a robust stockpile of nuclear weapons, a recommendation that figured prominently in the Clinton administration's support for a moratorium on nuclear testing.
Most important to Zimmerman with regard to the hafnium-triggering experiment, the Jasons had the scientific clout that would allow them to say whether a given scientific pursuit was outright harebrained. Zimmerman asked the Jasons to look at four principal questions: Did Collins indeed demonstrate that an "enhanced decay rate," or triggering, really took place? What is the physical mechanism that would allow the triggering to take place? Could enough hafnium be produced feasibly in the next 20 years to make it useful? Could a triggering mechanism be produced in the next 20 years?
The Jasons' conclusions, reached in July 1999, were damning on all four fronts. In essence, the Jasons concluded that the whole thing didn't pass the "snicker test," according to Zimmerman.
But there was a problem with the Jasons' study. Carl Collins, the man whose science was in question, never spoke to the group.
Even so, the study wasn't just about Collins's work. "Even if you trigger it, you couldn't use it as a weapon," said Steve Koonin, the provost of the California Institute of Technology, who led the Jasons' study. Hafnium-178 emits radiation like crazy; the amount required to fuel a bomb would require so much shielding to protect whoever is around the material that it would defeat the idea of having a small bomb. With the shielding, it wouldn't be such a useful bomb anymore, Koonin said. Finally, even if you could trigger hafnium in a bomb, it would be impossible to "burn" all the hafnium isomer. The resulting explosion, he said, would simply disperse a large amount of highly radioactive material. He paused for a second, and then said, "It sure would make a great dirty bomb."
A hafnium bomb, even if it didn't leave radioactive fallout, still wouldn't be like an ordinary bomb because, along with an explosive force, it would emit intense, penetrating gamma rays. According to Hill Roberts, a scientist at SRS Technologies in Huntsville, Ala., a gamma-ray bomb is appealing to some because gamma rays can pass through solid material and penetrate living tissue. Theoretically, an energetic gamma-ray burst could penetrate bunkers, killing whatever was inside -- be it humans or anthrax stockpiles. Putting it more bluntly, he said, "Tissue turns to goo."
But none of that would matter if an isomer bomb was flat-out impossible. Which was exactly what the Jasons concluded. Zimmerman thought he'd closed the book on the matter, and so did the Jasons.
In fact, the isomer bomb was just getting started.
The Argonne Group
Even if hafnium wasn't going to be a weapon, Collins's claims challenged conventional physics. Which raised a pressing question among government physicists: Could the results of the dental X-ray experiment be reproduced? In fact, the Jasons themselves, while arguing that hafnium couldn't be a weapon, suggested that another triggering experiment be done at a proper X-ray facility.