Brotherhood of the Bomb

HENRY HOLT AND COMPANY

Chapter One

Early in 1939, Ernest Orlando Lawrence, the Berkeley physicist and inventor of the cyclotron, was planning a machine to change the world. It would be the largest and most expensive instrument thus far dedicated to scientific research. Requiring enough steel to build a good-sized freighter and electric current sufficient to light the city of Berkeley, Lawrence's latest "atom-smasher" would, in theory, accelerate elementary particles to an energy of 100 million electron volts, enough to break the bonds of the atom and penetrate to its heart, the nucleus.

Almost a year after German scientists had first observed the fissioning of uranium, the atomic nucleus remained the unexplored ultima Thule of twentieth-century physics. Striking to its heart required giant machines capable of generating energies close to that of cosmic rays traveling from space. At such energies, charged particles, or neutrons, colliding with an atom broke it apart, laying bare its inner workings. The cyclotron was, in effect, a means of replicating the elemental forces of Nature.

Lawrence's first atom-smasher had been an unimpressive glass contraption barely 4 inchesacross, covered with red sealing wax against vacuum leaks. By 1939, that original cyclotron hung, like a trophy, above the entrance to one of the new laboratories on the Berkeley campus. Unprepossessing, it was yet the stuff of which the dreams of alchemy were made: a twentieth-century philosopher's stone, promising its possessor the ability to transform the elements of matter, once thought immutable.

But, beyond smashing atoms, exactly what the new machine would do remained mysterious even to Lawrence. The prospect he held up to Robert Gordon Sproul, the patrician president of the University of California, was worthy of a pre-Columbian explorer both for its sweeping vision and its lack of specificity: "Until we cross the frontier of a hundred million volts, we will not know what riches lie ahead, but that there are great riches there can be no doubt."

Like Paracelsus, Lawrence promised to turn lead into gold-but in infinitesimal amounts, and at prodigious cost. Mindful of the recent discovery of fission, Ernest chose to emphasize to Sproul another long-held hope of humanity that most scientists, he among them, had until now dismissed as illusory: "we may be able to tap the unlimited store of energy in the atom."

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Lawrence's moment of discovery had come a decade earlier, in early 1929. Then an unmarried twenty-eight-year-old associate professor of physics newly arrived from Yale, he was living at Berkeley's Faculty Club and working late nights at the university library. It was on one such lonely evening, while struggling through a recent article by a Norwegian engineer, Roll Wideröe, in a German journal, the Archiv für Elektrotechnik, that Ernest had his epiphany.

Wideröe's article was about a new way of speeding particles to high energies by repeated applications of a lower voltage. Resonance acceleration was an electromagnetic phenomenon without obvious practical application, in which positively charged particles are accelerated sequentially by electrical impulses as they pass through a succession of vacuum tubes. The acceleration ceased only when the experimenter ran out of tubes, or the particles fell out of step with the electrical impulses and spread out, shotgun-like, hitting the tube walls. A diagram in the article showed the vacuum tubes arranged in a straight line, end to end. Since his German was weak, Lawrence was drawn to the diagram rather than the text.

With the intuitive understanding that was always his greatest strength, Lawrence instantly recognized that if the particles could be confined to a circle rather than a straight line, and kept focused by a magnet while electrical impulses accelerated them-alternately pulling and pushing-there might be no limit to the energies obtained. The following day, Ernest excitedly described his idea for a "proton merry-go-round" to Berkeley colleagues.

For $25, Ernest built a tabletop model of his machine, debuting it a few months later before the American Physical Society. Lawrence reported on its promise to a September 1930 meeting of the National Academy of Sciences. Attached to a kitchen chair by a clothes hanger, it was a sensation among the scientists assembled. The first lilliputian device never achieved the energies that Lawrence promised the National Academy, but proved the principle sound. A twenty-five-year-old graduate student from Dartmouth, Stanley Livingston, helped Lawrence fashion his next machine of durable brass.

Progress thereafter was rapid, for both Lawrence and his machines. In 1930, at the age of twenty-nine, Ernest became the youngest full professor in the history of the University of California. Magnetic resonance accelerator-Livingston's term for the proton merry-go-round-gradually gave way to cyclotron, a word inspired by the particles' path and the Radiotron vacuum-tube oscillators that propelled them. Cyclotron had the additional bonus of sounding futuristic to prospective funders.

An enthusiast by nature, Lawrence began planning larger cyclotrons even before the capabilities of the existing one had been explored. A little more than a year after his first success, Lawrence and Livingston had built a machine capable in theory of accelerating protons to energies of 1 million electron volts. Measured by the diameter of the magnet's pole face, the 11-inch cyclotron was nearly three times the size of their first effort and cost disproportionately more to build: $800. Lawrence installed it, without fanfare, next to his office on the second floor of Berkeley's physics building, LeConte Hall.

That summer, Lawrence and Livingston discovered the principle of magnetic focusing, using soft iron shims between the poles and the vacuum tank to compensate for variations in the magnetic field. Voltages obtained by the 11-inch were doubled, and then doubled again-approaching the energy believed necessary to penetrate the invisible barrier that surrounds the atomic nucleus. Moving gradually up the slope, Lawrence and Livingston crossed the milestone million volts in August 1931. On a visit to New Haven to see his fiancée, Molly Blumer, Lawrence received the good news in a telegram from his secretary: "Dr. Livingston has asked me to advise you that he has obtained 1,100,000 volt protons. He also suggested that I add `Whoopee!'"

Ernest wed his longtime sweetheart in May 1932. Molly was a tall, statuesque Vassar honors graduate whose father was dean of Yale's medical school. Enrolled in bacteriology courses at Radcliffe, Molly gave up her own promising scientific career to marry Lawrence. While still on their honeymoon, the newlyweds had just returned from a sail on Long Island Sound when Ernest learned in a radio broadcast that British scientists had been first to disintegrate an atom, using a simple voltage multiplier and a few hundred thousand volts. In a properly designed experiment, the 11-inch could have accomplished the same feat a year earlier. Quickly returning to California, Ernest made sure that he and his colleagues got credit for achieving the first atomic disintegration outside Europe. He promised Molly a longer honeymoon later.

The British discovery highlighted the fact that Lawrence's enthusiasm sometimes overcame the discipline necessary to do science. Since he was often more interested in building grand new machines than in doing the hard work necessary to interpret experimental results, Ernest had paid less attention to having sensitive detection instruments.

To remedy that weakness, Ernest imported a friend from his Yale days, Donald Cooksey, a journeyman physicist who specialized in designing detectors. The son of a Yale professor and scion of an old California family, Cooksey had never bothered to finish the language requirement for his graduate degree. Nine years older than Lawrence, Cooksey was more cosmopolitan by far. Ernest's first view of the New York City skyline had come from the roof of the Yale Club, where he was staying as Cooksey's guest. "DC," as he was known, soon became Ernest's factotum, troubleshooter, and confidant at the lab.

Following his embarrassment at the hands of the British, Lawrence proposed an order-of-magnitude increase in the power of his next cyclotron. Early in 1932, he and Livingston had begun sketching plans for a 27-inch machine capable of accelerating particles to energies in excess of 20 million volts.

There would be no more trophies to hang on the wall. In the otherwise relativistic world of cyclotron physics, one linear relationship ruled: an almost direct correlation between input and output. Higher energies required proportionately larger and more powerful vacuum pumps and electromagnets. The magnet for the 11-inch cyclotron had weighed 2 tons. For the 27-inch, Lawrence already had his eye on an 80-ton magnet, originally built for a Bay Area firm, the Federal Telegraph Company, but now obsolete and rusting away in a Palo Alto junkyard.

Bigger machines and an expanding empire also required more room. Lawrence installed the 27-inch in an old wooden building on campus known as the Civil Engineering Testing Laboratory; the forestry and linguistic departments still maintained offices upstairs. He christened the structure, somewhat grandiosely, the "Penetrating Radiations Laboratory," a title later shortened to "Radiation Laboratory." For the growing number of grad students gathering around him, however, it was simply the "Rad Lab," just as their remarkable young phenom of a professor was "EOL."

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By sheer force of personality more than by any power of intellect, Lawrence was a commanding presence at Berkeley by the early 1930s. Although tall and good-looking-he was over six feet, with startlingly blue eyes and a shock of blond hair combed straight back-Lawrence spoke in a tenor rather than a baritone and was never comfortable addressing large groups.

Ernest was born of Norwegian immigrants at the start of the new century. His father, Carl, was school superintendent and later president of a teachers college in Canton, South Dakota. Ernest's mother, Gunda, recalled an early childhood spent in a sod hut on the prairie. Educated at St. Olaf College and the University of South Dakota, Ernest developed values that were decidedly, even determinedly, midwestern.

Yet Lawrence's plebeian background had not yielded egalitarian beliefs. Primus inter pares would never be a familiar concept at the Rad Lab. To the cyclotroneers, EOL was "the Maestro" or simply "Boss." Visitors to the lab noticed a single gleaming china teacup and saucer amid the workers' grimy porcelain mugs. Following the morning coffee break, Cooksey locked the cup and saucer as well as a silver-plated spoon in a drawer conspicuously marked "Reserved for the Director."

Like a medieval lord, Lawrence presided over weekly meetings of the physics department's Journal Club-convened promptly at 7:30 every Monday evening in LeConte's library-from a massive red leather chair reserved for him alone. It was the one time that the cyclotron was turned off. Ernest introduced the presenter, usually asked the first question, and brought the proceedings to an abrupt close exactly ninety minutes later with the first ring of the campanile's chimes, even if it meant interrupting the speaker in midsentence.

Colleagues from eastern schools found Lawrence's informal manner popular with students, if somewhat disconcerting. Physicist Henry DeWolf Smyth, visiting from Princeton, was dismayed by one of Ernest's typically boisterous pep talks: "This seemed to me a rather inappropriate talk to a group of graduate students presumably of some sophistication. I found, however, not only that this was the tone of the talk which depressed me somewhat but it seemed to work, which depressed me even more."

Ernest's strict Lutheran upbringing meant that frustrations and setbacks at the cyclotron seldom provoked expletives stronger than "Fudge!" or "Oh, Sugar!" But Lawrence, for all his Scandinavian stolidness, had a quick and livid temper. When it flared, a vein stood out above his left temple-a kind of weather gauge and warning to students and colleagues alike.

Disdainful of most human frailties, Lawrence had a particular intolerance for lying. Once, after berating Molly for not listening to an interview he had given on the radio, Lawrence was brought up short by her reply: "Ernest, would you rather I lied?"

The anodyne to Lawrence's withering temper was his charm, equally celebrated and just as quick to surface. When Northwestern University had tried to lure him from Berkeley, Sproul joined with the head of the physics department, Raymond Birge, to thwart the attempt. As ammunition to persuade the regents to promote Lawrence to full professor, Birge and Ernest's colleagues wrote a long letter to Sproul. In it, Lawrence's affability and winning personality were given almost as much prominence as his research.

Possessed of energy and enthusiasm in seemingly equal measure, Lawrence terrorized the Rad Lab's cyclotroneers-whom he affectionately called "the boys"-when at the controls of the machine. In those early days, starting the cyclotron involved closing a knife-switch. This simple act, noted one of the boys, was sometimes accompanied by an "ensuing sparking, crash, and blowing out of lights," plunging the campus and even adjacent neighborhoods into sudden darkness.

Once the cyclotron was running, Lawrence always tried to coax the maximum voltage out of the machine. A penciled mark next to a slide-switch in the control room indicated the pinnacle reached on the last attempt. Success was measured by the intensity and focus of the ionized particle beam, which emerged into the target chamber as a thin line of bright blue light. These sessions, usually brief, ended when an oscillator tube burned out or the cyclotron's vacuum chamber sprung a leak-whereupon Ernest cheerfully promised to return when the boys had the problem fixed.

Hazards abounded. The popular method of locating vacuum leaks-by playing a jet of natural gas over the sealing wax-was likened by the boys to a race between explosion and asphyxiation. The cyclotron bathed its operators in so much radio frequency energy that it inspired a favorite trick: standing next to the machine, a cyclotroneer could get a lightbulb to flicker in one hand by holding onto a grounded piece of metal with the other.

Frequent electrical faults caused heavy hooks to fall from overhead cages, shorting out the cyclotron with a resounding bang and an overpowering smell of ozone. Water spraying from the cooling system that Cooksey installed-common garden hose, for the most part-sparked fires as often as two or three times a day. The boys then ran around the machine with handheld extinguishers, desperately trying to put out the flames before they spread to the wooden floor, which was soaked with highly flammable transformer oil. (One cyclotroneer, puzzled that strangers at campus parties were always able to guess where he worked, finally realized that the sickly sweet smell of the oil on his clothes was the giveaway.)

Seemingly oblivious to the smoke, water, and stench of burned insulation, Lawrence remained resolutely hunched over the controls, pressing on to higher voltages and more tightly focused beams for as long as the current flowed.

Ernest's obsession was legendary at Berkeley. Late at night or even in the early morning hours, Lawrence-sometimes still in formal wear, having just arrived from a dinner party at Sproul's house-would appear without notice in the control room and demand a report on the current experiment from the cyclotron's stunned operator. These impromptu nocturnal visits came to be known, not always affectionately, as the "bed check." Canny graduate students learned to leave the lights burning, their coats on a hook behind the door, while they stole away for dinner. Cyclotroneers grew used to the sight of Molly sprawled asleep in the red leather chair, following what Ernest had promised would be only a brief detour to the lab before dinner or a movie. Two-year-old Eric, the couple's first child, learned to salute his father's colleagues with a cheery, "How's the vacuum?"

On those occasions when illness kept him at home, Lawrence remained in touch by means of a bedside radio tuned off station to the cyclotron's operating frequency. When the telltale hum ceased, Ernest was instantly on the telephone to inquire whether the machine was down or the boys simply malingering.

(Continues...)

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Excerpted from Brotherhood of the Bomb by GREGG HERKEN Copyright © 2002 by Gregg Herken
Excerpted by permission. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.

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