By WILLIAM J. BROAD After suffering a heart attack, Edward Teller took a breath, sat down with a friend and a tape recorder and offered his views on the secret history of the hydrogen bomb. "So that first design," Dr. Teller said, "was made by Dick Garwin." He repeated the credit, ensuring there would be no misunderstanding. Dr. Teller, now 93, was not ceding the laurels for devising the bomb — a glory he claims for himself. But he was rewriting how the rough idea became the world's most feared weapon. His tribute, made more than two decades ago but just now coming to light, adds a surprising twist to a dispute that has roiled historians and scientists for decades: who should get credit for designing the H-bomb? The oral testament was meant to disparage Dr. Stanislaw M. Ulam, Dr. Teller's rival, now dead, and boost Dr. Richard L. Garwin, a young scientist at the time of the invention who later clashed with Dr. Teller and now says he would wipe the bomb from the earth if he could. The New York Times obtained a transcript of the recording recently from the friend with whom Dr. Teller shared his memories. Some historians of science praise Dr. Teller's tribute to Dr. Garwin as candid; others fault it as disingenuous. In any event, the recognition of Dr. Garwin is surprising because he is not usually seen as having a major role in designing the hydrogen bomb. In fact, he eventually became an outspoken advocate of arms control, battling often with Dr. Teller. The tribute also poses the riddle of how Dr. Garwin's work, done in the early 1950's, could have gone unacknowledged for so long. "It's fascinating," said Dr. Ray E. Kidder, an H-bomb pioneer at the Lawrence Livermore National Laboratory in California, which Dr. Teller helped found and once directed. "There's always been this controversy over who had the idea of the H-bomb and who did what. This spells it out. It's extremely credible, and I dare say accurate." Dr. Priscilla McMillan, a historian at Harvard who is working on a book about the early H-bomb disputes, agreed, saying the tribute sounded right. She added that Dr. Teller might have done it to "square things with God" after his 1979 heart attack. One of the most controversial figures of the nuclear era, Dr. Teller played central roles in inventing the atomic and hydrogen bombs, and in destroying the career of Dr. J. Robert Oppenheimer, who in World War II had run the laboratory in the mountains of New Mexico that gave birth to the atomic bomb. Afterward, though, he questioned the morality of devising an even more powerful weapon, and amid the anti-Communist paranoia of the McCarthy era, the government stripped him of his security clearance. The schism among scientists over his fate lasts to this day. In the process, Dr. Teller became a hero to conservatives but was disparaged by liberals as the role model for Dr. Strangelove, the fictional mad scientist of Stanley Kubrick's 1964 film who was fixated on mass destruction. Dr. Garwin, during the design effort a half-century ago, was a 23- year-old faculty member at the University of Chicago who was working during the summer break of 1951 at the New Mexican weapons laboratory, known as Los Alamos. Over the decades, he rose to prominence, often advising the government on secret matters of intelligence and weapons. In an interview, Dr. Garwin said Dr. Teller was correct to include him among the bomb's designers, likening himself to its midwife. "It was the kind of thing I do well," he said of joining theory, experiment and engineering to make complex new devices. But he added, "If I could wave a wand" to make the hydrogen bomb and the nuclear age go away, "I would do that." Now 73, Dr. Garwin is an experimental physicist who for decades has worked at the International Business Machines Corporation and is now a senior fellow at the Council on Foreign Relations in Manhattan. He backs such arms control measures as the Comprehensive Test Ban Treaty to outlaw all nuclear explosions. A theoretical physicist, Dr. Teller is a senior fellow at the Hoover Institution at Stanford and director emeritus of the Livermore weapons laboratory. He was an ardent advocate of the Reagan administration's Star Wars antimissile plan and, more recently, has promoted the idea of manipulating the earth's atmosphere to counteract global warming. If Dr. Teller's version of events is right, he and Dr. Garwin were the main forces behind one of the most ominous inventions of all time, a bomb that harnessed the fusion power of the sun. Dr. Teller had championed the goal since the early 1940's, long before the atomic bomb flashed to life. His basic idea was to use the high heat of an exploding atomic bomb to ignite hydrogen fuel, fusing its atoms together and releasing even larger bursts of nuclear energy. But no one working at Los Alamos could figure out how to do that. The credit dispute has its roots in a conversation Dr. Teller had in early 1951 with Dr. Ulam, then a mathematician at Los Alamos. Afterward, a new plan emerged. The idea, known as radiation implosion, was to build a large cylindrical casing that would hold the atomic bomb and hydrogen fuel at opposite ends. The flash of the exploding bomb would hit the case, causing it to glow and flood the interior of the casing with radiation of pressure sufficient to compress and ignite the hydrogen fuel. No one knew whether the idea would work. And studies of it were slowed by ill will between Dr. Teller and Dr. Ulam, as well as debates at the weapons laboratory over whether building a hydrogen bomb was ethical and smart, given its potentially unlimited power. Dr. Garwin arrived at Los Alamos in May 1951 from the University of Chicago, where he had been a star in the laboratory of Enrico Fermi, the Nobel laureate and arguably the day's top physicist. Dr. Garwin had been at Los Alamos the previous summer and, intrigued by the work, had come back for another atomic sabbatical. In the interview, Dr. Garwin recalled that Dr. Teller had told him of the new idea and asked him to design an experiment to prove that it would work — something the Los Alamos regulars failed to do. "They were burnt out" from too many rush efforts to build and test prototype nuclear arms, Dr. Garwin recalled. "So I did it." By July 1951, after talking at the weapons laboratory with physicists and engineers, he had sketched a preliminary design. Of its features, Dr. Garwin said, "There is still very little I'm allowed to say." He continued working on the design until he went back to Chicago that fall. Then, as momentum built at Los Alamos for the H-bomb, many experts joined the design effort, which was finished in early 1952. The prototype bomb stood two stories high. In November 1952, it vaporized the Pacific island of Elugelab, a mile in diameter. Its power was equal to 10.4 million tons of high explosive, or about 700 times the power of atomic bomb dropped on Hiroshima. Unlike its atomic predecessors, the hydrogen bomb theoretically had no destructive limits. Its fuel was cheap, and its force could be made as large as desired. Scientists talked of doomsday weapons big enough to blow the earth's atmosphere into space, or to raise ocean waves that crushed whole nations. Many books and articles were written about the dark feat. Most mentioned Dr. Teller and Dr. Ulam and their rivalry. Few if any mentioned Dr. Garwin's role. All details of the invention were shrouded in secrecy to try to keep Washington's foes in the dark. The backdrop to Dr. Teller's testament is the reactor accident in Pennsylvania at Three Mile Island in March 1979. As the nation panicked, Dr. Teller, an ardent backer of nuclear power, went on a public relations blitz to insist that the crisis was one of politics, not technology. In May 1979, he stressed the point to Congress. The next day, Dr. Teller, then 71, suffered a heart attack. "He called me from the intensive care unit," recalled Dr. George A. Keyworth II, a friend of Dr. Teller's at Los Alamos who later served as President Ronald Reagan's science adviser. He said the elder physicist began the call with two assertions: "Heart attacks are painful, and I have discovered that I am not immortal." Dr. Keyworth recalled: "He was frightened, like a child." Upon release from the California hospital, Dr. Teller came to Los Alamos to recuperate. He sat down with Dr. Keyworth in September 1979 to detail his H-bomb views. A copy of the transcript, which Dr. Keyworth recently gave The New York Times, ran to 20 pages. It was a long rebuttal of the idea that Dr. Ulam played any role in developing the hydrogen bomb. Instead, Dr. Teller asserted, he alone made the key theoretical breakthrough after a decade of work. Then, he said, he told Dr. Fermi's star pupil about it, "and I asked him to put down a concrete design" and make it "so hard that there should be the least possible doubt about it." "So that first design was made by Dick Garwin," Dr. Teller said. "It was then criticized forward and backward. In the end, it stood up to all criticism." Dr. Teller said the scientists who worked out the details of the design were Dr. Marshall Rosenbluth and Dr. Conrad Longmire. After Dr. Garwin went back to the University of Chicago in the fall of 1951 and Dr. Teller returned to Los Alamos in December 1951 to check on progress, "I found that the calculations came out just as I had expected" and that "the design remained unchanged." "And therefore, as far as I'm concerned, the preparation for the hydrogen bomb was completed by Dick Garwin's design." In an interview, Dr. Keyworth judged that Dr. Teller's memory at that time "was as good as it gets," and he said Dr. Teller put no restrictions on how to treat the testament. "He simply had a near-death experience," Dr. Keyworth said, "and was thinking of his place in history." Two years later, at a meeting in Italy of a dozen scientists including Dr. Garwin, Dr. Teller alluded to the younger man's role in public. "The shot," he said, "was fired almost precisely according to Garwin's design." After that, Dr. Teller and Dr. Garwin clashed for years over Star Wars, which Dr. Teller helped create and Dr. Garwin criticized as a dangerous fantasy. Silence ruled afterward. Dr. Teller, in his 1987 book, "Better a Shield Than a Sword," did not mention Dr. Garwin's design in a long account of the H-bomb's development. Nor did Dr. Teller's biographers, Stanley A. Blumberg and Louis G. Panos, authors of "Edward Teller: Giant of the Golden Age of Physics" in 1990, though they had a transcript of the testament. In an interview yesterday, Dr. Teller stood by his 1979 portrayal. "He filled in the details very effectively," he said of Dr. Garwin. "He made the design and that was it." And Dr. Teller denied slighting Dr. Garwin in earlier accounts of the breakthrough. "He was a good man who did it in record time." That judgment was lost to history, however. In 1995, Richard Rhodes, in his book "Dark Sun: The Making of the Hydrogen Bomb" found that Dr. Teller actually delayed the bomb's development and made no mention of Dr. Garwin's role. In an interview, Mr. Rhodes said that in praising the 23-year-old outsider, Dr. Teller was "essentially saying the guys at Los Alamos couldn't cut the mustard." And that assertion, he said, was false. But Dr. McMillan of Harvard disagreed, saying that while Dr. Teller could be combative and vindictive, he was also generous and fair. The testament, she said, should probably be taken at face value. Few players in this drama survive, making it difficult to clear things up. Dr. Jacob Wechsler, who was a young man on the hydrogen bomb team, said the Los Alamos regulars, not Dr. Garwin, were the real stars. "We had to hit this with a sledge hammer," he said. Dr. Rosenbluth, a main H-bomb designer at Los Alamos, said his own role was underplayed in the testament but that nevertheless he substantially agreed with Dr. Teller. "Dick understood physics," Dr. Rosenbluth said, "and certainly produced the embodiment that was actually constructible." He added that Dr. Garwin was virtually unique at Los Alamos in his ability to bridge gaps between experts in different fields. "I was a pure theorist, and there were a lot of experimental engineering types, but there weren't many people able to serve as a link between the two," Dr. Rosenbluth said. Dr. Garwin was probably the project's intellectual glue, tying many ideas into the successful device, he said. "He's an extremely brilliant person and has this rare combination of talents," Dr. Rosenbluth said. "Fermi had them. But in the generation after Fermi, Dick may be the best exemplar." Over the decades, Dr. Garwin said, he spoke publicly of his role in the hydrogen bomb on more than one occasion. But he added that he was advised early in his career, "You can get credit for something or get it done, but not both." Copyright 2001 The New York Times Company