1—
The He-Man Cyclotron
Skinning Cats
It took a man of singular determination and self-confidence to propose a cyclotron capable of accelerating particles to 100 MeV. The substantial cost—projected at perhaps a million dollars—was not at first the major impediment. Nature, not money, seemed to set a limit to the size of cyclotrons. The difficulty, that the increase of mass with speed claimed by the theory of relativity would destroy the synchronism expressed in the cyclotron equation (2.1), had been noticed in 1931, by Livingston and by Feenberg; but the limit, whatever it might be, evidently did not affect the performance of the first cyclotrons, and the menace faded from view. When presenting Lawrence with the Comstock prize in November 1937, W.D. Coolidge saw no obstacles: "The limit to the particle energies which can be generated in this way is not yet in sight."[4] Precisely at that moment, however, Bethe and his student Morris E. Rose declared that in their calculations relativity limited the maximum energies obtainable in a cyclotron to about those achievable with the 37-inch machine. They observed that to
compensate for the continually rising mass, the magnetic field must increase toward the periphery of the orbit to keep the circulating particles in phase with the oscillator. But to focus the particles in the median plane, the field must decrease from the center outward. The cyclotroneer wants both resonance and focusing; nature requires a choice.
According to Bethe and Rose, the best that can be done is to sacrifice exact resonance; but even so, and with the best field design they could contrive, maximum energy would be 5.5 MeV for protons, 8 MeV for deuterons, and 16 MeV for alpha particles. This estimate supposed 50 kV on the dees; with 100 kV something more could be done, since the accelerated particles would acquire energy more quickly and so have more of it when they finally fell out of phase with the accelerating voltage. Still the outlook was grim. With a magnetic field of 18 kilogauss and a final orbit 37 cm in radius, deuterons of 11 MeV would emerge, "the highest obtainable with as much as 100 kV dee voltage." For such a cyclotron, pole faces 34 inches in diameter would suffice. "Therefore it seems useless to build cyclotrons of larger proportions than the existing ones."[5]
When the Laboratory received this news, it was engaged in what, according to the Cassandras of Cornell, was a wasteful and useless task. But its experience with the 37-inch gave it confidence that the 60-inch could go beyond 10 MeV despite the most refined calculations to the contrary. Lawrence wrote Bethe that relativity had not yet begun to inconvenience cyclotroneers; the existing inhomogeneities in the magnetic field of the 37-inch defocused more menacingly than the mass increase and indicated considerable room for maneuver in the 60-inch. And if shimming were to fail, other possibilities existed, for example, placing wire mesh across the mouths of the dees so as to obtain by electrical force the focusing that would be lost by adjustment of the magnetic field to secure resonance. "We have learned from repeated experience that there are many ways of skinning a cat."[6]
This response was not bluff. For a year or so Robert Wilson had been poking around inside the cyclotron tank, determining empirically the strength of the vertical component of the electric field near the dee mouths and of the radial component of the fringing magnetic field, which drives ions toward the meridian plane. The investigation of the circulating current, which eventuated in the internal target for isotope production, was part of his study. Wilson painstakingly worked out the trajectories of ions beginning their courses at any distance from the median plane and reaching the center of the gap in phase with the maximum field there. His numerical integrations showed that from about 10 cm out, where the focusing effect of the electric field becomes negligible (it decreases with the particles' energy), the magnetic field swiftly reduced the vertical amplitude of the beam from a spread of some 5 cm near the ion source to about 1 cm at the exit slit. Probe measurements confirmed Wilson's semi-empirical deduction of beam width as a function of orbital radius. He therefore felt confident in recommending that the aperture of the dees also be made to decrease with radius, thereby reducing their capacitance and easing the performance requirements for power oscillators to accelerate protons.[7]
Wilson presented his results in a seminar about the time that Bethe and Rose's letter of November 24 was circulating in Berkeley. The circumstances inspired McMillan to estimate the defocusing effect of relativity. It was he who found that for the 37-inch defocusing arising from inhomogeneities in the magnetic field exceeded that from relativity by a factor of four. Also, McMillan calculated from experience at Berkeley that the beam could fall out of phase with the electric field by more than 60° and still get through the cyclotron; and on this basis he calculated that the maximum energy of deuterons achievable without altering basic cyclotron design was perhaps 
MeV with 100 kV on the dees. With Lawrence's grids, he thought, any amount of electrostatic focusing could be attained.[8] On this last point McMillan had a short and victorious duel by mail with Bethe, who had thrust forward the opinion that "no change of the shape of the dees, no
insertion of grids at the dee openings, etc., can have any appreciable effect on the electric focusing." McMillan parried that Bethe had mistakenly assimilated a dee with grid to an open dee of smaller aperture; Bethe concurred, and allowed the possibility of doubling the energy limit.[9]
Meanwhile Rose, who had also been working for a long time on cyclotron focusing, sweated to get his theory ready for the press. Whereas Wilson and McMillan relied on their experience with a single machine, Rose began with general equations of motion in changing electric and magnetic fields and deduced, by clever substitutions, a differential equation for the excursion of an ion from the median plane as a function of the phase of the radio frequency voltage it met as it crossed between the dees. His treatment of the general case—which "had been considered much too complicated for solution by many"—agreed with the conclusions about electric and magnetic focusing reached in Berkeley.[10] Rose could do more: from his differential equation he could deduce the maximum energy obtainable without defocusing the beam when the gradient of the magnetic field compensates for relativity. He ended more generous than he and Bethe had begun. They allowed, in a note added to their initial announcement on December 4, that a field giving an angular velocity too large for resonance at the start and too small at the finish could deliver deuterons of 17 MeV with V = 50 kV, a number Rose raised to 21.1 MeV. These numbers would be multiplied by 
if 100 kV were placed across the dees. Rose thought that no greater potential could be reached without severe difficulty and that grids would not have the power Lawrence supposed. "It seems very possible that the energies mentioned [21.1 MeV deuterons] represent the natural upper limit for the cyclotron with the given dee voltage of 50 kV, at least without very radical changes in design."[11]
As Bethe conceded to McMillan, after explaining that he and Rose had published hurriedly because "we considered the existence of a relativistic limit so important that we thought we should communicate it to cyclotronists as quickly as possible, without endeavoring to give accurate figures," "it makes all the difference in the world whether the limit is 8 MV or 20."[12] Or 100. The question came before that high tribunal of science, Time , whose investigative science editor, Walter Stackley, drew from Lawrence a firm rejection of the 20 MeV limit. There was new work under way at Berkeley, Lawrence said, "which may increase the energy maxima materially." "We believe that there are experimental possibilities of improving focusing conditions which remove the limitation on energy to some unknown point."[13] And, just at this point, L.H. Thomas, known to physicists as the discoverer of a relativistic effect important in atomic theory (the "Thomas precession"), described a novel way to achieve both focusing and resonance by a magnetic field that had notably different strengths in several pie-shaped sections into which he divided the median plane. Thomas's ingenious suggestion received some attention at Berkeley and more at Stanford, where Oppenheimer's former student Leonard Schiff continued the calculations. Although the scheme, which is difficult to put into practice, was not exploited at the time, it gave ample evidence that nature did allow for several methods of cat-skinning.[14]
The opinion of the experienced cyclotroneer about Bethe's limit is nicely reflected in notes by the Rockefeller Foundation's Tisdale. After recording that "Joliot's cyclotron, by a lucky chance, is designed just to the limit of the theoretical voltage," which would have been at once a triumph and an end to the Foundation's investments in cyclotrons, Tisdale reported that Paxton would have none of it. "P[axton] considers that the mass effect is not very important."[15] The cyclotroneer did not doubt that so refined a thing as a relativity effect could be beaten by brute force.
Thornton: "Difficulties in reaching high voltages seem to me quite real. . . . But of course there are a number of ways [by] which one may get around [Bethe's] objections." Wells: "It can probably be compensated by applied magnetic inhomogeneities of the field or by properly chosen electrostatic fields." Compton: "[It] can be passed (theoretically) by altering pole pieces and electrostatic focusing. Thus no limit is now assignable." Oliphant: "I am not deterred by papers which have been written on the maximum energy obtainable from a cyclotron."[16] Gentner looked to Thomas's method. Cockcroft preferred to follow Lawrence, who thought azimuthally changing magnetic fields impractical and no longer favored fitting the dees with wires. Instead, he bruited a solution in the style of the Old West: put a million or two million volts on the dees and drive the beam home before it knows that it has been defocused.[17]
Skinning Fat Cats
Lawrence was planning to build far beyond the Bethe-Rose limit even before the 60-inch machine, which itself crossed the suppositious threshold, came on line. It was not relativity, but money, he said in a radio broadcast in the spring of 1939, that stood in his way. "Right now we are considering the possible financial difficulties of constructing a cyclotron to weigh 2,000 tons and to produce 100 million volt particles. . . . It would require more than half a million dollars."[18] Both the size and the price were to grow during the next year with the help of the University of Texas and the Nobel Foundation, and with the encouragement of big-thinking colleagues. "I hope your new apparatus is really big," Chadwick wrote, with 60 or 70 MeV in mind. "Best wishes for the beam to end all beams. The best is none too good for the Berkeley boys," wrote I.I. Rabi of Columbia, who would later try
to snatch the best from Berkeley in the interests of East Coast physics.[19]
Lawrence faced difficulties beyond the relativistic and the financial. For one, there was no uncontested space for a 2,000-ton cyclotron on the Campus. An engineering annex had been needed to house the 27-inch; a special building had been erected for the 60-inch; real estate as large as the Campus would be reserved for the new machine. Then there was a taint of overreaching, of imprudent haste, of gluttony, in the plan. "In some quarters it might be considered no less than shocking that we should be looking towards a larger cyclotron almost before the 60 inch is in operation."[20] And finally, there was the disagreeable fact that no major discovery had yet been made in any cyclotron laboratory. As Arthur Compton and his colleague A.J. Dempster pointed out to the Rockefeller Foundation, cosmic-ray physicists had made several of the most spectacular discoveries in physics during the 1930s, in particular the positron and the mesotron, and cosmic rays come gratis.[21]
To this objection Lawrence replied with a claim about the might-have-been and a statement of the what-should-be. The claim: cyclotron physicists had missed the discoveries through a compulsion to perfect their machines; in due course they would have found what others detected earlier with more primitive means. The statement: a discovery has little value unless it can be turned to practical use. "It means a great deal more to civilization, let us say, to find a new radiation or a new substance that will cure disease than it would to discover a super nova." On this reasoning, Joliot and Curie's find would have been barren had it not been for the Berkeley cyclotron. And, Q.E.D., "the discovery of mesotrons in cosmic rays will be of little value in the course of time unless there is developed a way of producing them, and learning of their manifold properties—ultimately to be put in the service of mankind."[22]
The invocation of mesotrons and the hint that the projected cyclotron might make them came to the fore only after the University of Texas had set going a mechanism that would provide more money than Lawrence thought possible. He and Sproul turned, indeed spun, to one prospective donor or influential intermediary after another. For a time Walcott, the former senator with the leukemic son and a trustee of the Carnegie Institution, looked like an especially valuable contact. Walcott had contacts in big steel; funding would be easy, Lawrence said, if the steel were donated. The son, a physician, came to Berkeley to work with, and receive radiophosphorus from, John Lawrence. A very strong affection developed between the Lawrences and Cooksey and the Walcotts; but it did not bring steel for nothing or save Walcott's son.[23] Other possibilities: Lewis Strauss, proposed by Oppenheimer and approached through Coolidge; Spencer Penrose, the dying benefactor of the Penrose Foundation, approached through Frank Jewett of Bell Labs; Edsel Ford and General Electric, approached through Dave Morris.[24]
To his own considerable surprise, Weaver turned out to be the route to the pot of gold. We know his attitude on Rockefeller Foundation support of research cyclotrons. During the negotiations over Paxton and Laslett's foreign missions, he had formed the notion that Lawrence was "a happy-go-lucky sort of individual," a good scientist, but indecisive and not overly solicitous about the inconvenience his changes of plan caused others.[25] And in his dealings with Lawrence in the spring of 1939, Weaver had not been pleased by the escalation of the Laboratory's request between discussion and submission.[26] It is doubtful that he
received with much enthusiasm the news that Lawrence was coming East to look for donors of the $750,000 he reckoned as the amount yet to be raised for an instrument of 1,500 to 2,000 tons to crack the region above 100 MeV. The $750,000 arose by subtraction of the $250,000 Sproul promised to raise from the million that Lawrence, who liked round numbers, thought necessary. On the advice of Poillon, who judged that a request for a cool million would put off donors, Lawrence set the total at a lukewarm $900,000 and the balance at $650,000. This was the amount Morris requested of Edsel Ford, with an overheated inducement: "As this is an instrument which will enlarge the frontier of science almost beyond belief it should be something epoch-making and will link the names of those connected with it alongside of Newton and Einstein."[27]
The justification for this instrument, as outlined to Sproul early in October, when it had grown to 2,000 tons, had no more substance than the rationale Morris offered Ford. There was a more definite and practical reason, however. The success of the cyclotron had inspired competitors, including two clones of the 60-inch; if the Laboratory wished to stay ahead, it must cross the new frontier, where, as cosmic ray studies indicated, "strikingly new and important things" were to be found. Sproul wanted to keep Berkeley ahead. He promised (so Lawrence relayed to Weaver) not only to raise part of the capital outlay but also to finance the operation of the he-man machine. Still, Weaver did not expect that his trustees would take much interest in the proposal, or in any costly esoteric project, in the state of the world in the fall of 1939. Here Lawrence guessed more accurately than Weaver. "I personally am banking on the trustees' taking the view that it is in just such times as these that the Rockefeller Foundation should undertake such important projects, thereby demonstrating a stability and confidence in the progress of civilization."[28]
Lawrence opened negotiations with the Rockefeller Foundation in New York on October 27. Weaver accepted the desirability of
a cyclotron that endowed particles with 100 or 200 million electron volts; he encouraged Lawrence to think big, to beware of "initial presentation [of the project] on too small a scale;" and he insisted that the plan make clear that the cyclotron would be a national, even international, facility, "located at the University of California . . . [but] built for all science." Weaver assimilated Lawrence's project to what he called the Foundation's "national laboratory," the 200-inch telescope and its facilities abuilding on Mount Palomar; and he estimated its costs correspondingly, at $1.5 million including operating expenses for a decade.[29]
The announcement on November 9 that Lawrence had received the Nobel prize for physics in 1939 (about which we shall say much more in a moment) strengthened Weaver's commitment to the Palomar of the vanishing small. With the ardor that the higher administration of the Foundation had once censored as excessive, he celebrated Lawrence's prize in a confidential bulletin sent to the Rockefeller trustees and invited the prize winner to put forth a detailed plan for presentation to the next trustees' meeting, in April 1940, a plan so complete that it would kill any fear that similar or competing requests would arise.[30] "This is the sort of thing which should be done superbly—or not at all. And done superbly it is of compelling attractiveness." Lawrence responded that it should be superb, and raised the weight of the magnet to 3,000 tons, or perhaps (indecisively or flexibly) a little more, and he promised to have full plans for a 180-inch and a 205-inch cyclotron ready for discussion with Weaver in Berkeley in January. Lawrence naturally favored the larger version, as offering a chance of delivering 400 MeV alpha particles.[31]
When Weaver arrived on January 7, he was hit with a plan for a magnet weighing over 4,000 tons. He had come with Lawrence's estimate of $750,000 in mind and the notion that it,
and perhaps as much again in operating expenses and auxiliary equipment, could be raised in equal shares by the Rockefeller Foundation, the University of California, and industry. "The size to which I found the project had grown, when I arrived at Berkeley [in January]," Weaver sighed, "carried me so far beyond any figures which I had ever discussed." Lawrence wanted $1.5 million of an estimated $2 million from the Foundation. In Lawrence's upbeat report to Poillon, Weaver did not "seem to be unduly distressed . . . [and] went away far more eager to consummate the project than when he came." Weaver had fallen under the spell of the California sunshine man and of the 60-inch cyclotron, then treating cancer patients and, on demand, charring plywood with a directed energy beam of deuterons released into the air. Weaver suggested to Sproul "the bare possibility" that the Foundation might give as much as a million dollars.[32] Back in the cold East, Weaver discovered that the Foundation's president, Raymond Fosdick, who had been enthusiastic about the project in December, had lost his conviction, and doubted that the trustees would give even $500,000. The January plan was dead. Or so Weaver wrote Sproul, whose recent appointment as a Rockefeller trustee closed the funding loop. "It does not seem to me a desperately serious matter if this project is delayed somewhat. Professor Lawrence is fortunately still young, there is a great deal of rich experience which can be gained with the 60-inch cyclotron, and there is a negligible danger that anyone else will run away with the ball."[33] This was to ignore Texas, still out in left field awaiting its fly, and Lawrence's flexibility.
During January and early February, friends of the Laboratory brought pressure on Fosdick and their acquaintances among the Rockefeller trustees. Among the friends were old supporters like Poillon, who hoped, perhaps, that something might be realized at last from the Research Corporation's cyclotron patents; Karl Compton, a Foundation trustee; former ambassador Morris, of the
Macy Foundation; and Alfred L. Loomis, who spent the riches he amassed as an investment banker on a private laboratory and the encouragement of physical research. An expert instrument designer himself, Loomis was much taken with the Laboratory on his first visit there late in 1939; his wide influence among officials of corporations and foundations made his support of the project, which he pledged in December, a most valuable acquisition.[34]
Weaver also made a play among the trustees. He pointed out to Karl Compton the happy parallel between Lawrence's project and the 200-inch telescope. "Such a cyclotron would, I think, be correctly and generally viewed as the definitive instrument for the investigation of the nucleus—the infinitesimally small—just as the 200" telescope is viewed as the definitive instrument for the investigation of the universe—the infinitely great." Compton visited the Laboratory and returned "radiant over all the wonderful things he saw in Berkeley" and convinced that the new machine "should be built adequately large to reach the range of energy above 160 million volts in order to attack the problem of mesotron forces."[35] After a visit from Weaver, another Foundation trustee, George Whipple, a frequent recipient of hot iron from Berkeley, declared himself keen on the project, and certain that funds would be forthcoming from somewhere; he spoke "with an enthusiasm which is very unusual for him concerning Lawrence and his group, saying that the way they do things out there is 'just right.'"[36]
Weaver also collected professional evaluations. He asked Bohr, Bush, both Comptons, W.D. Coolidge, Jewett, Joliot, and Oliphant whether "expert opinion of the world of science is reasonably unanimous in viewing [the giant cyclotron] as one of the most interesting, the most potentially important, and the most promising projects in the whole present field of natural science."
The replies might have made Lawrence blush. Bohr: "It would be greeted with utmost pleasure by all physicists." Bush: "This opportunity is the most interesting, the most potentially important, the most promising project of large magnitude in the whole field of natural science." A.H. Compton: "If anyone can make a success of a 2000-ton cyclotron, Lawrence can. . . . On the whole, the investment would be a nice one." K.T. Compton: "I would definitely place it in the number one position by a large margin." Coolidge: "Now is the time to do it while the exceptional combination of enthusiasm, intelligence, experience and skill of Dr. Lawrence and his group are available." Jewett: "[Its] value . . . is of course beyond question." Joliot: "The realization of such an apparatus is likely to bring important results. . . . Lawrence is, without any doubt, the most qualified man to undertake its construction." Oliphant: "It is essential that the construction of the cyclotron should be carried to the limit by Professor Lawrence."[37]
All this lobbying cancelled Fosdick's timidity. At a meeting in mid February, which Poillon attended, "the Rockefeller [administrative] group distinctly favor[ed] the larger [cyclotron] because of the certainty of its performance within and above the 160,000,000-volt range."[38] The 160 MeV referred to one of several designs that Lawrence had supplied when he realized there was no chance of $1.5 million from the Foundation. The 205-inch, perhaps so chosen to beat Palomar, fell to 184 inches, the largest size of commercially available steel plate. And the 150-inch stayed in the running. On February 20, 1940, Lawrence provided Weaver with four options: (a) 184 inches, $1.5 million, handsomely housed and fully equipped, operating at 2,500 kW to kick ions to 200 MeV before relativity could take its toll, the "conservatively ideal in exploiting the limit of the cyclotron method;" (b) 184 inches, $1 million, cheaply housed and partially equipped, operating at 700 kW and perhaps yielding 100 MeV deuterons, easily stepped up to (a); (c) 184 inches, $875,000, a skeleton, deficient in copper and steel, producing 75 MeV
deuterons, capable of upgrading to (a); and (d) 150 inches, $750,000, able to reach 100 MeV with an oscillator more powerful than (c)'s, but not easily refashioned into (a). Lawrence took his stand between the most desirable and the least expensive: "It seems to me that attention should be concentrated on projects 'b' or 'c', of course very much preferably 'b'." The 160 MeV probably referred to option (b) and alpha particles, since, with his ear for audience, Lawrence had advised Weaver to couch his statements in terms of alpha energies, which are twice those of deuterons for the same cyclotron parameters and somewhat less afflicted by relativistic mass increase.[39]
The fundamental alternative—184 inches versus 150 inches—represented a hedged bet. On the one hand, option (a) and its upgradable lower forms would quite possibly be able to materialize mesotrons. DuBridge and Karl Compton emphasized the desirability of building the machine that, as Compton put it, allowed a "reasonable expectation of producing mesotrons." The reasonableness depended on estimates of the mesotron's mass. Karl Compton thought 160 MeV might do; DuBridge, "energies of the order of 100 million electron volts."[40] Oppenheimer and Fermi, who happened to be in Berkeley, put the mass of the mesotron between 70 and 120 MeV, gave it a 90 percent chance of falling under 100 MeV, and advised that the higher the bombarding energy—the closer to option (a), "which exploits the full practical potentialities of the cyclotron method"—the greater the chance of making mesotrons in the cyclotron.[41] Lawrence rated the materialization of mesotrons "the most fundamental experimental problem that one can formulate at the present time," and thought he could succeed with 150 MeV. But he did not promise. Although mesotrons might fail to materialize, the energy region above 100 MeV was nonetheless certain to be rich: "we cannot help but entertain the possibility of nuclear chain reactions by starting
them off with sufficiently energetic particles and that maybe a hundred million volt particles will do the trick. . . . Should this prove to be true, we will have a discovery of great immediate practical importance. On the one hand, we will have a practical philosopher's stone transmuting elements on a large scale; and, as a corollary thereto, we will have tapped, on a practical scale, a vast store of nuclear energy."[42]
Despite these formidable arguments, Lawrence retained option (d). He thus deprived the trustees of the Rockefeller Foundation of the option of arguing that if they could not put up enough for mesotrons, they should put up nothing at all. Lawrence had opened his mind on the matter to Weaver during a telephone conversation at the end of January: "The point is that it is far more important to get into the new territory now. We would rather build a, say, haywire outfit and actually have been up there than to take a chance on going up later and maybe not getting there at all." Occasionally he thought to go for the 150-inch and not risk its loss by groping for mesotrons, and he so advised Weaver by telegram. As he explained his position to Poillon, who had heard similar arguments from him before, the most important thing was "to accomplish the original and primary objective of attacking the energy range in the atom above one hundred million volts. . . . We will be in entirely new territory. . . . It is distinctly of secondary importance that we get a little further in by going 50% higher."[43] As in the old days, Lawrence set goals expressible not in terms of progress in physics, but in terms of increase in decimals.
Weaver decided to take two options before the trustees in April: $750,000 for the 150-inch; or $1 million toward the 184-inch, on condition that the University raise at least another $250,000 for it. In either case, the University would have to provide operating costs for a decade.[44] Sproul had already obtained authorization from the Board of Regents for the $250,000 he had promised for construction and either $50,000 or $85,000 a year for maintenance of the smaller or larger machine respectively. Sproul
regarded the commitment of such sums by the regents to such a purpose as "pretty overwhelming."[45] It remained only to await the decision of the trustees. They reviewed the opinions of the physicist and engineering consultants from Bush to Oliphant. They had a lesson in nuclear physics and its applications from Karl Compton, who had been coached in Berkeley (plate 10.1), and from Weaver, who drew on inspirational photographs of the Laboratory and its machines supplied by Cooksey. And they heard a heady peroration from their program officer. Weaver compared Lawrence's Laboratory with Bohr's institute; he recommended that the Foundation support the 184-inch project, as an "opportunity to make discontinuous change in [the] rate of progress of science;" and he extolled the "shrewd intelligence, imagination and insight, unselfishness, inspiration for young men, [and the] charm" of the man who would carry the project through.[46] And there would be no trouble carrying it through, as the trustees learned from Jewett, now speaking as head of the National Academy of Sciences: "a matter of engineering calculation [he said] and not one of uncertain speculation."[47]
As a further aid to their deliberations, the Rockefeller trustees felt heavy pressure transmitted through their officers from Lawrence's agents and admirers Poillon and Morris. They were not content with the prospect of a million dollars. "I am making life miserable for Warren Weaver and Raymond Fosdick," Morris had written Lawrence at the end of February. "Confidentially, we are all striving for the million dollar cyclotron under column B, and Howard [Poillon] and I are trying to jack up this limit 12 and one half percent. I really feel that all four of us are working for
you heart and soul."[48] The quartet missed its pitch by 2.5 percent.
At noon on April 3, 1940, Weaver called Lawrence to announce that the trustees had come down 15 percent above the expected maximum.[49]
WW: Our trustees voted $1,150,000 . . .
EL: Really, Warren, $1,150,000 . . .
WW: And with the $250,000 that makes $1,400,000, which you see is the full original budget.
EL: The full original budget. . . . Its hard to tell you how I feel. This is the most wonderful thing that has ever happened. . . . I'm coming to New York, and it will give me a chance really to explain my feelings to you. This is the most wonderful thing that one can think of in the world.
Lawrence had the feeling he was "walking on air." So did his successful agents Morris and Poillon. "You can scarcely overestimate the joyous feeling that resulted from the news," Poillon said, and indeed he had earned the right many times over to share in this tribute to the machine and Laboratory he had backed from the beginning. The munificent grant represented many things: dollars, to be sure, but also the affection, respect, and confidence in which Lawrence's fellow physicists and prominent men of business held him. As Dave Morris wrote: "This really great triumph should mean much to you in more ways than one. There was no disagreement anywhere along the whole line. Great and small, technical and lay, they all backed the PLAN and YOU. Do get full emotional satisfaction from such rare unanimity: you deserve it."[50] According to the formal agreement, the Rockefeller Foundation and the University would put up money as Lawrence needed it in the proportion of 23:5 until June 30, 1944, when, barring "unforeseen difficulties," the machine was to have been completed.[51]
The University immediately obtained a fifth of its commitment of $250,000 from the Research Corporation. Lawrence asked the Markle Foundation for the balance, toward which it gave $50,000 at Weaver's urging, and tried to get Westinghouse to underbid General Electric's generous offer to make the 184-inch's power supply at cost, which Westinghouse declined to do. He spent two weeks touring Wall Street with Loomis, asking for help in knocking down the price of steel and other material and equipment. Despite the pressure of war orders, which left little incentive for price concessions, Loomis and Lawrence did very well on Wall Street. The balance of the University's share of the capital costs eventually came from the federal government, in consequence of those unforeseen but foreseeable difficulties that prevented completion of the machine before June 1944. And the war also made good the shortfall in Lawrence's ideas of eluding relativity; the machine when finished in 1946 operated on a principle invented by McMillan in 1945, perhaps as a result of his wartime experience with radar.[52]
In a public explanation of the gift, and before the unforeseen difficulties interrupted the building of the 184-inch cyclotron, Fosdick wrote: "With so much creative human talent employed in devising increasingly powerful engines of destruction it is at least some comfort to know that today in the United States work is proceeding on two of the mightiest instruments the world has ever seen for the peaceful exploration of the Universe." The 200-inch telescope and the 184-inch cyclotron would respectively open up the infinitely great and the infinitely small, alleviating "the insatiable curiosity which is the mark of civilized man." To be sure, the cyclotron would do something practical: it would produce specialized radioactive isotopes, perhaps beams of therapeutic value, perhaps even clues to the exploitation of atomic energy. But above all, "like the 200-inch telescope, it is a mighty symbol, a token of man's hunger for knowledge, an emblem of the undiscourageable search for truth which is the noblest expression
of the human spirit."[53] This inspired gloss, which was not entirely disingenuous, marks the end of the era of private support for Lawrence's Laboratory.
Lucky Dog
The Rockefeller Foundation had heard three substantive objections to the he-man cyclotron: that relativity would cripple it; that the muse of discovery did not attend cyclotroneers; and that the Foundation would further its program in the applications of physics to biology by favoring the production of natural, rather than artificial, isotopes of the elements of living things. All these objections lost much of their force while the Rockefeller trustees pondered. The second two both collapsed with the detection of H3 and C14 , two solid discoveries that promised to give biologists tracers for the most important ingredients in organic molecules. Lawrence made much of both these products of his Laboratory. He gave the discovery of H3 pride of place in his report to the Research Corporation for 1939. "Radioactive hydrogen," he wrote, in a gloss he doubtless expected Poillon to pass on to the Rockefeller trustees, "opens up a tremendously wide and fruitful field of investigation in all biology and chemistry."[54]
Toward the end of the dickering, in late February 1940, Kamen and Ruben called on Lawrence, then in bed with one of his colds, to present their first, flimsy evidence of the existence of C14 . "He jumped out of bed, heedless of his cold, danced around the room, and gleefully congratulated us." His ecstasy turned to outrage on learning that the report of the discovery in the Physical Review bore the names Ruben and Kamen. "He turned on me [Kamen recalled] with ill-concealed anger and demanded to know why my name and the institutional credits placed me and the Rad Lab in a position secondary to the Chemistry Department." The explanation, that Ruben thought he needed all the credit he could amass to gain tenure in a Chemistry Department not free from anti-Semitism, did not placate Lawrence, who thought the Laboratory needed all the credit it could garner to win the Rockefeller
sweepstakes. "The best of all," Lawrence wrote Weaver, in an itemization of favorable signs, "is the discovery of carbon 14 by Kamen and Ruben [!] here. . . . All cyclotrons now in existence could be usefully employed in making radio-carbon only."[55]
The third objection—that Lawrence did not know what he was doing, that the maker of the cyclotron knew too little physics, that he had overstepped the limit set by Einstein and nature—was answered emphatically by the certifiers of the world's greatest physicists. On November 9, 1939, Lawrence received the telegram from Stockholm that responded to the recommendations of distinguished physicists throughout the world. The Swedish Academy of Sciences had decided to award him the Nobel prize in physics, "for your having invented and developed the cyclotron and especially for the results attained by means of this device in the production of artificial radioactive elements." He thus fulfilled almost to the volt the prophecy made by Jesse Beams eight years before: "With 10–8 amps at 900,000 volts you already have a powerful tool and Boy with 20,000,000 you'll get the Nobel prize."[56]
Lawrence was first proposed formally in 1938, by an American, a Japanese, and an Indian (who proposed a division with Fermi). The prize committee could not decide whether the cyclotron was prizeworthy and chose Fermi for his discovery of radioactive substances and the method of activation by slow neutrons.[57] In 1939 the Compton brothers organized a campaign for Lawrence among former American prizewinners (all prizewinners have a permanent right of nomination); two of them, Clinton Davisson and Irving Langmuir, did propose Lawrence; Carl Anderson preferred Stern; Millikan did not care to exercise his franchise. The usual rationale for the nomination was, as Langmuir put it, Lawrence's "construction of the cyclotron and his studies of radioactivity that have been made possible by its use." Another ground, which
perhaps agrees better with the facts, was expressed by Livingston in a letter forwarded to the Nobel committee by Davisson. Livingston observed that many people before Lawrence had had the idea of the cyclotron. "However the idea developed," Livingston continued, "Lawrence was the first and only one to have enough confidence in it to try it out. . . . His optimistic and inspirational attitude was what convinced me it was worth working on." And thus their division of labor: "Professor Lawrence's ability as a director and organizer and his inspirational leadership amount almost to genius, but the bulk of the development was done by others."
The foregoing enumeration does not exhaust the list of Americans who proposed Lawrence for the physics prize for 1939. Two invited to nominate that year, E.F.W. Alexanderson of General Electric and the eminent surgeon Harvey Cushing, plumped for him; and Bethe and R.C. Gibbs of Cornell decided that if Lawrence did not win, they would use their invitation to nominate for 1940 on his behalf. In a few words, as DuBridge wrote Lawrence after the happy news, "there seems to have been an unanimous feeling for the past two years at least that you were the outstanding candidate among American physicists for the Nobel award."[58] And he had powerful support in places where he was not a favorite son. The Italians—Amaldi, Fermi, and Rasetti—endorsed him unanimously, after Fermi's victory in 1938; the most influential Scandinavian physicists, Bohr and Manne Siegbahn, favored him; and even the British, or anyway those who did not think that Cockcroft and Walton had the prior claim, "would have made the award in the way the [Nobel] Committee did."[59]
There was rejoicing in Berkeley (plate 10.2). Birge worked out that Lawrence was the thirteenth American to win a Nobel prize in science and the first to have won while employed at an American state university. The Physics Department and the administra-
tion of the University, which had reduced Lawrence's teaching load and given him money, therefore deserved a share of the honor, Birge wrote Sproul. "I think if the outside world realized more fully the handicaps under which we work, in getting and retaining men of real eminence, it also would consider the whole collection of events leading up to this award as a seeming miracle." The regents proclaimed that the prize ranked Lawrence "with the greatest scientists of the world." Lawrence knew better and graciously associated his collaborators with the honor.[60] In turn they gave him a high-spirited party—a "jubilation"—at their favorite Italian restaurant. Aebersold provided an apt text, which the celebrants sang to the tune of "A Ramblin' Reck from Georgia Tech:"[61]
The prexy came around to see the gadget put to test
Of course the young professor wished to show it at its best
"You may fire the thing when ready, boy," the eager prexy cried
So Lawrence pushed the switches in and quickly stepped aside.
He aimed it at the window pane and smashed out all the glass
It hit a poor old alley cat right square upon his—face
He turned it on some students and it swept them off their feet
He bombed the Campanile and he moved it down the street.
And then he bombed some common lead and turned it into gold
The prexy jumped around with joy and loudly shouted, "Hold
I am convinced the thing is good—no more I'll have to go
To the Solons up in Sacrament' to ask them for some dough.
The publicity surrounding the prize—which made Lawrence the subject and victim of the advertisements he had courted—was its most important and useful feature.[62] As Weaver observed in his telegram of congratulations: "Some of us think they were a year or two late. But this definitive recognition is nonetheless particularly useful just now." What Weaver had in mind appears more clearly in Lawrence's letter of thanks to Siegbahn. "It was already clear
that the difficulties in the problem [of attaining 100 MeV] were no longer technical but purely financial. The added prestige to the work of our laboratory which the Nobel award brings . . . will make it possible for us to raise the large financial support for this great project."[63] The prize, like the successful operation of the 60-inch cyclotron, would undercut those who doubted the feasibility and/or desirability of a machine rated at five times the Bethe-Rose limit and encourage foundations willing to take risks endorsed by the Nobel authorities. Lawrence understood the power of the prize to confer legitimacy on new fields or doubtful adventures; in a report written in 1938, he had pointed out the useful advertisement provided by Nobel laureate Joliot's decision to build a cyclotron.[64] Several successful fund-raisers made the same observation as Weaver, among them Walter Alvarez, Cottrell, and Poillon.[65] And Lawrence spread the message widely in his answers to the several hundred letters and telegrams he received; to more than fifty of these correspondents he excused the honor, and opened his thoughts, by observing that the cyclotron would be the beneficiary of his placement among the demigods of science.
The size of the projected cyclotron grew along with its prospects in the nourishing light of the Nobel prize. The plan for a 2,000-ton machine with 120-inch pole pieces, considered, at a cost of $500,000, to be at the edge of the attainable in October 1939, swelled to a dream of a 5,000-ton atom smasher with poles of 205 inches. Answering Bohr's congratulations of November 14, Lawrence referred to a machine of 3,000 tons; answering G.W.C. Kaye's on December 30, he mentioned his Christmas wish of 5,000.[66] It is very likely that without the Nobel prize Lawrence would not have had the boldness to have doubled his design and his costs. The 184-inch machine owes its existence as much to the prize givers of Stockholm as to the exertions of Warren Weaver.
The award to Lawrence honored not only the invention of an instrument but also the creation of the environment necessary to exploit it. What the Nobel committee had in mind appears best from the award letter quoted earlier: they were impressed by the invention and development of the machine and "especially" by its application to the production of radioisotopes. The same emphasis appears in the committee's report to the Swedish Academy of Sciences, which dwells on output figures: the cyclotron easily makes artificial sources of gamma rays equivalent to a hundred grams of radium and gives a hundred times the neutrons from a kilogram of radium mixed with beryllium. Reference to production does not occur, however, in the official citation ("for the invention and development of the cyclotron and for results obtained with it, especially with regard to artificial radioactive elements") or in Bohr's statement of Lawrence's achievement ("for the extraordinarily great contribution to the study of the reactions of atomic nuclei that he has made by construction of . . . the so-called cyclotron").[67] The official citation and Bohr's recommendation suggest that Lawrence himself made some notable contribution to radiochemistry or nuclear physics with the help of the cyclotron. Indeed he did: the cyclotron laboratory. But he himself had not uncovered much new about the nucleus. Had the Nobel committee wished to distinguish inventors of an accelerator who had made a fundamental discovery with it, they did not have far to look. Cockcroft and Walton fit the description and had the additional advantage over Lawrence of priority. And their work was considered prizeworthy. Otto Schumann of Munich nominated them for 1935; Rutherford and Fowler did so in 1937; Chadwick took up their cause in 1938 and 1939; and the Nobel committee agreed that both their "pioneering" splitting of the nucleus and their exact determination of atomic masses had "a special importance." In 1951 they did share the prize "for their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles."[68]
In preferring Lawrence to Cockcroft and Walton, the Nobel committee on physics went against its own arguments and precedents, although in a direction of which Nobel would have approved. Lawrence's was the first award for the development of an instrument for physics if we leave C.T.R. Wilson's prize of 1927 out of the reckoning. Efforts to give prizes for hardware alone had subsequently failed. In 1935 Walther Nernst proposed Hans Geiger. The Nobel committee thus evaluated his candidacy: "One can say that the Geiger counter together with the prizewinning Wilson chamber are the experimental instruments that have made possible the brilliant discoveries in nuclear physics. . . . But Geiger himself has not taken any noteworthy part in the work that led to these important discoveries."[69] A campaign of many years on behalf of Aimé Cotton, who built a very large electromagnet (100 tons, 75 cm pole tips, 64 kG) for the Paris Academy of Sciences and used it for important spectroscopic studies, likewise did not convince the committee. Pieter Zeeman (prize of 1902) might compare Cotton's magnet with Aston's mass spectrograph or the Rowland grating, and insist that progress in physics comes equally from ideas and from machines; C.E. Guillaume (prize of 1920) might declare Cotton's magnet precious and its research potential prizeworthy; Pierre Sève of Marseilles might demand a reward for "the construction of an instrument unique in the world . . . , the Laboratoire du Gros Electroaimant, where many workers under [Cotton's] direction have already obtained extremely important results in all branches of physics;" but the committee rejected it all, on the ground that Cotton had not made any discovery with his magnet important enough to deserve a Nobel prize.[70]
The relaxation of this condition in Lawrence's favor owed much to the progress and popularity of nuclear physics and to the scale of the machines and laboratories it required. One of Cotton's last nominators, C.E. Guye of Geneva, realized that, if the Nobel committee went for machines, they would probably prefer those of nuclear to those of atomic and molecular physics.
The only hope of the old school, he thought, was to slip in before the committee could decide which of the inventors of accelerators or discoverers of new particles to reward first. It was in connection with the confusion and profusion of claimants that the eventual need to pick an accelerator physicist was first expressed in the correspondence of the Nobel committee. Dick Coster of the University of Groningen, writing in December 1933, suggested that the "artificial disintegration of nuclei by fast protons" might prove deserving; two years later Caltech's Richard Tolman took advantage of the throng—Lawrence, Lauritsen, Van de Graaff, and Cockcroft and Walton—to dismiss all in favor of Caltech's Anderson.[71] By 1938 Lawrence had outdistanced the rest in the building not only of machines but also of laboratories.
An instructive evaluation of the situation as it appeared to three nominators that year is preserved in the correspondence of O.W. Richardson (prize of 1928), who liked neither big nor nuclear physics. Bohr (prize of 1922) talked over options with him in December 1938. "After discussing a number of distinguished names, to several of which I would have been prepared to offer a measure of support, he finally decided on the combination of Lawrence and Kapitsa [another big machine, big laboratory man]. Well, what has Lawrence done? invented an instrument which would have been more or less obvious to anybody unfamiliar with the difficulties of experimental technique, made it to work, and done nothing with it, except to incite a large number of very able experimental physicists all over the world, unsuccessfully, to emulate his efforts. The wiser of them seem to have handed this trouble over to their students, but it is doubtful if that will help their generation! As for Kapitsa!!!" The addressee of this blast, G.P. Thomson (prize of 1937), who did some nuclear physics, returned the suggestion of Cockcroft without Walton. Bohr had also considered a prize for Cockcroft alone, but all recognized its unacceptability. In the end Bohr dropped Kapitsa, and Richardson and Thomson nominated E.V. Appleton, whose investigations concerned the upper atmosphere.[72]
Appleton had to wait until 1947. The Nobel committee was infatuated with nuclear physics and its machinery and willing to reward discoverers of the one and inventors of the other. Oliphant read Lawrence the significance of the committee's decision in 1939: "It is extremely encouraging to find that the Nobel Prize Committee, in common with many other authorities, is now recognizing the tremendous importance of technique in scientific investigations. . . . The technical side of the subject is now recognized as equally important with advances that follow from the use of these techniques, and more important, I hope, than the theories that endeavor to explain them. . . . It is certain that you have no difficulty now in raising funds for your 'father of all cyclotrons.'"[73]
German submarines kept Lawrence from the prize giving in Stockholm. The citation and medal were sent to the Swedish consul in San Francisco and presented at a ceremony on the Berkeley campus presided over by Sproul. Birge gave a speech reciting the accomplishments of Lawrence and the Laboratory. It was the evening of February 29, 1940. At the end of his prepared remarks, Birge announced the discovery of C14 to the crowd that filled the hall. "On the basis of its potential usefulness," Birge said, with exaggeration appropriate to the hour, "this is certainly much the most important radioactive substance that has yet been created."[74] Lawrence's reply carried two examples of his most effective technique. For one, he let Birge say what he himself wished to say without incurring any obligations: "As [Birge] has indicated, there are substantial prospects that [the next cyclotron] will be the instrument for finding the key to the almost limitless reservoir of energy in the heart of the atom." For another, he did not miss the opportunity for fund-raising. "It goes without saying that such a great recognition at this time will aid tremendously our efforts to find the necessary large funds for the next voyage of exploration into the depths of the atom." "[This] very considerable financial problem . . . we must now hand over to President Sproul."[75]
As we know, description of the cyclotron had always been a parade ground for military metaphors. The additional possibilities offered by the source of the Nobel prize carried the "University Explorer" to heights truly and doubly inspired. "Ernest Lawrence," he declared, "has discovered a blasting technique far more potent than anything Alfred Nobel ever dreamed of." R.W. Wood, an elder statesman of physics, improved the metaphor into prophecy. He wrote Lawrence: "As you are laying the foundations for the cataclysmic explosion of uranium (if anyone accomplishes the chain reaction) I'm sure old Nobel would approve."[76]