The Clinton P. Anderson Meson Physics Facility, familiarly

The Clinton P. Anderson Meson Physics Facility, familiarlyknown as LAMPF, is a striking example of the Laboratory’s

transition from an institution primarily involved in weapons-relatedresearch to one aggressively engaged in a diverse range of basic andapplied research. At the heart of LAMPF is a half-mile-long linear

accelerator that produces a beam of protons with a maximum energyof 800 million electron volts. That in itself is not particularlyremarkable: other accelerators exceed this energy by a wide margin.

But no other proton accelerator in the world even approaches thecombination of energy and average beam intensity—1 milli-ampere—that can be supplied by LAMPF.

A primary purpose of the proton beam, in its own right a valuablescientific tool, is production of secondary beams of pi mesons (henceLAMPF is often called a meson factory. The pions are produced asthe protons strike light-element targets. Decay of the pions createsmuons, and decay of the muons yields muon and electron neutrinos.In addition, interaction of the protons with heavy-element targetsproduces neutrons. These particles—the protons, pions, muons,

neutrinos, and neutrons—are used as probes for obtaining informa-

n the early 1950s Los Alamos wasstill probably the most renowned nu-clear science laboratory in the world.Our renown was based on a capabil-

ity built up in a very short time during thewar. Expertise in nuclear science wasabsolutely essential to the tasks that LosAlamos had to do. After the war we con-tinued to work on a great many remaininguncertainties, many of which involved nu-clear properties, such as neutron cross sec-tions and spontaneous fission rates.

Its geometry matching the architectureof the mesa on which it lies, the ClintonP. Anderson Meson Physics Facility(LAMPF) is the world’s foremostproducer of pi mesons. Hidden withinthe structures are impressive arrays ofequipment-and scientists who respondhappily to the news that the beam is onand despondently to the news that thebeam is off.

LOS ALAMOS SCIENCE Winter/Spring 1983

tion about the structure and properties of nuclei and the nature of thenuclear forces. This information, in turn, is used to test the success of

quantum electrodynamics and theories unifying the forces of nature.First proposed in 1962 and ready for use in 1973, the facility is

host to hundreds of scientists from all over the United States andmany foreign countries. LAMPF’s usefulness to these scientists hasbeen enhanced by many additions, including facilities for treatmentof cancer with pions, for research with neutrons and neutrinos, andfor production of isotopes. Under construction at present is a protonstorage ring that will permit generation of short-duration, extremelyhigh-intensity neutron pulses. Hopes for the future include a high-intensity neutrino facility in conjunction with the proton storage ring

and LAMP II, a kaon (K meson) factory using the present

accelerator as an injector.How did this extraordinary research facility come into being on a

mesa dotted with prehistoric Indian ruins? Louis Rosen, a foremostadvocate of LAMPF since its conception, here reminisces on itsorigins and talks about its present and future.

Anyway, we were in the early 1950s theworld’s foremost nuclear science laboratory,but the world was catching up with us. Bythe end of the decade, we no longer wereahead. Although we had some nice equip-ment and quite a few outstanding people,other laboratories, not only in this countrybut in Europe as well, had either caught upwith us or surpassed us. This situationcaused us some concern and frustration.

It was also in the late 1950s that Dr.Bradbury, among others, started to addressthe fact that since Los Alamos was going tobe a national security laboratory with primeresponsibility for nuclear weapons, we had tohave a broad base, not only in nuclearscience but in other areas as well. He en-couraged efforts on the part of the staff tothink of ways to diversify the Laboratory.However, he assumed that we wouldn’tdiversify in a promiscuous way—I feel weeventually did just that, but not duringBradbury’s tenure. We were careful then toundertake activities that were pertinent ornecessary to carrying out our responsibilities

in the weapons area. For example, manyscientists are interested in finding ways tosolve nonlinear equations, but here we had tofind ways to solve them.

We diversified into areas that were vital tosupport of our basic mission and into otherareas only if they had the earmark of beingimportant national goals and of being in-capable of pursuit by either industry oruniversities. One of those areas was nuclearrocketry. It didn’t materialize-it fellflat-but it was the kind of thing that couldonly be done in a multidisciplinary nationallaboratory. Another area we entered washigh-temperature gas-cooled reactors, whichmay yet turn out to be the safest, mostefficient, most appropriate way to generatenuclear power. But funding in this area wascut off. I think that was a terrible mis-take—the government really blew it whenthey abandoned that technology. GeneralAtomic is trying to revitalize it, but it shouldhave been pursued here. We could havedeveloped it much faster and moreeconomically.

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Toward the end of the 1950s we mademajor improvements in the cyclotron hereand we built a vertical Van de Graaff, and sowe could hope to keep pace with othernuclear science laboratories. Then, about1959, my wife told me she just had to getaway from Los Alamos. I applied for aGuggenheim Fellowship and, despite myapplication’s being way past the deadline,received one. The Fellowship was amarvelous thing. Not only was it quite a lotof money for those days, five thousanddollars, but it was tax free. I let Mary choosewhere to go. Since she had stuck with me atLos Alamos, I figured it was now her turn.She chose Paris.

What does one do in Paris other than lookat pretty girls? There was then, and still isnow, a major laboratory, Centre d’EtudesNucleaires, located just outside Paris at

Saclay. It has always been the foremostbasic nuclear science laboratory in France.We lived in Paris, and Mary reveled in its artand language schools and its beautiful shopswhile I commuted through its kamikazetraffic every day to Saclay.

That year at Saclay was great because itgave me a chance to think about where LosAlamos should be going. Also, I wrote morepapers that year than in any year before orsince, and I even did a little research. Asregards Los Alamos, I convinced myself thatwe had to do something really major innuclear science if we were, on the one hand,to fulfill our obligations to support a strongnuclear weapons program and, on the otherhand, to maintain the prestige and creden-tials that would permit us to attract the veryhighest caliber of scientific people. A labora-tory is, in first approximation, made up notof hardware and computers and buildingsbut of people—dedicated, competent people,well educated in the activities that you wantto pursue but, more important, inspired bythe magnitude of their ignorance.

So in France I convinced myself thatsomething dramatic had to be done. Back inLos Alamos I continued in my research—

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with polarized beams—and started talkingwith others about what that somethingshould be. One group of people thought itshould be solar sailing, propelling enormousvehicles just by the sunlight bouncing offthem. But that seemed to have little relevanceto anything. Another group wanted to have alarge astrophysics program, which mademore sense because astrophysicalphenomena are not all that far removed fromnuclear weapons phenomenology. And agroup led by Jim Tuck was pushing veryhard in the direction of controlledthermonuclear energy. I tried to help Jim andsucceeded in providing him with neutronspectra demonstrating that he had achievedtrue thermonuclear reactions in one of hisdevices. Energy from nuclear fusion seemedthen, and still now, a good thing for theLaboratory to pursue, because the payoff istoo far down the road for industry to beinterested.

However, although I had never taken aformal course in nuclear physics, my ownleanings were toward nuclear science. I felt,and some others agreed, that we should thinkin terms of a great nuclear science facilitycentered around what we dreamed of as theworld’s most powerful meson factory. Nopoint in thinking small: if you are going to dosomething, you may as well go all the way.Well, the arguments for such a facility had tobe very compelling because it obviouslyinvolved lots and lots of money—upward ofa hundred million dollars for developmentand construction. We finally worked outwhat seemed an honest and very persuasiverationale for requesting of Congress theresources to build LAMPF.

The most fundamental reason we ad-vanced stemmed from a belief, still heldtoday, that eventually this country and theentire industrialized world will be forced,whether they like it or not, to a nuclear-energy economy. Safety is not going to havemuch to do with it. We are simply runningout of conventional organic sources ofenergy, and there is the much more funda-

mental problem of the effect of carbondioxide on the earth’s climate. Every scien-tific investigation of this problem points tothe conclusion that there is a limit on howmuch carbon dioxide we can spew into theatmosphere without causing quitecatastrophic climatic changes. Now that is anatural limit, not a human-made limit. Sowhat can we do? We can stop using so muchenergy and go back to a primitive economy,but nobody is going to agree to that. Theother possibility is to find another energysource. Fusion energy would be great, butit’s not at all clear that it will happen in thenext fifty years, not at all. And solar energy

cannot serve for really large-scale productionof electricity, ever. The big source of energyrequired by industrialized societies is goingto have to come, very soon, from nuclearfission and later, maybe, from nuclear fusion.

If a nuclear-energy economy is inevitable,how can we make it as efficient and safe aspossible? With advanced nuclear tech-nology. The reason we are doing so badlynow with power reactors is that we didn’tstart with enough technology. And becausetechnology is the child of science, we need astrong science base. Without that, tech-nology cannot advance and will soon dry up.We felt that the need for science as the basisof technology was the most compellingreason for Los Alamos to engage, at a veryhigh level, in basic nuclear science. However,

there were other reasons.One was that many senators were seeking

some kind of national facility for this part ofthe country, which was very poor in thatrespect. But we had to convince people that,in contrast to the rest of the Laboratory, thefacility would be open to all interested users.People feared that after capitalizing on theirsupport to get LAMPF built we would put afence around it, and they would be outsidelooking in. Fortunately, I was reasonablywell known in the scientific community, andI think people believed me when I told themwe would do no such thing. And the UsersGroup charter, which was adopted long

Winter/Spring 1983 LOS ALAMOS SCIENCE

LAMPF

before construction was complete, backed upour intent in this regard, It states that theusers, the hundreds of them, will be involvedin the governance of LAMPF. The entirescientific community can participate. Wedon’t say, “Look, come and use whatever wehave if you can use it, but don’t tell us whatyou need or what we should do.” Users areinvolved in determining policy for upgradingthe facility, for new beam lines, and forexperimental programs, and, of course, theyare primarily and heavily involved in advis-ing on the allocation of beam time. Althoughthe users do not make the final decisions,they advise us on what scientific prioritiesshould be assigned to various proposals.Incidentally, Los Alamos people competewith everybody else. They get no preferencein allocation of beam time, with one minorexception—the beam to the Weapons Neu-tron Research Facility.

This exception is another reason forLAMPF. While the accelerator was beingbuilt, I told the Congress that we shouldinclude a facility for doing research with ahigh-intensity neutron beam because eventu-ally the question of a nuclear test ban wouldarise. In the presence of a ban, maintainingthe cadre of very bright people needed fornuclear weapons design would be very dif-ficult unless they had something interestingto do related to their primary tasks. Lo andbehold, Congress understood completelyand with minimal debate authorized thefunds for WNR. The facility is now operat-ing, and its capabilities will soon be dramati-cally increased by the proton storage ringnow under construction.

It is interesting that the version ofLAMPF being built by the Russians, whichwill provide a lower current of somewhatlower energy protons, has included a protonstorage ring from the start. I believe theirfacility is being built primarily for use in theevent of a test ban. They may or may not usethe mesons, but they will certainly use theneutrons.

Getting back to the reasons for building


the facility, a final but very important reasonwas education. LAMPF provides a greatarena where faculty and students cantogether teach and practice the art andscience of solving interdisciplinary problems.The very large number of publications anddoctoral theses based on research atLAMPF attests to its excellence as an educa-tional tool and, in a larger sense, as aneducational environment.

Speaking of education, I was disheartenedby what I heard at last summer’s AAASSymposium on Research and the FY 83Budgets. The many speakers from the Con-gress, from the Office of Science and Tech-nology Policy, and from the Office of Man-agement and Budget left me with the im-pression that, although this administration isgoing to support basic research perhapsbetter than any other, it does not recognizethat federal support for education is of primeimportance to a first-class researchendeavor. I believe that education in thiscountry, in the primary schools, the secon-dary schools, and, in most cases, the univer-sities, is not producing the number andquality of people that are needed to maintaina high-technology society. But the ad-ministration, as nearly as I can tell, does notfeel that it is a federal responsibility toimprove the situation. To agree that thegovernment should fund research and yet todeny that the government should activelypromote good science education seems acontradiction.

But let’s be grateful for the good news.This administration clearly recognizes thatresearch is important and is going to providemoney for it, no question. I have never feltmore comfortable about LAMPF’s funding.Ten years ago the situation was quite dif-ferent. I had the feeling then that people inWashington were hiding from me. OnceJohnny Abadessa, the comptroller for theAEC, gave a colloquium here. Halfwaythrough he spotted me in the audience, andsaid, “Ah, Louis Rosen is here. Every time Italk to him, it costs me a million dollars.”

Now it is a pleasure to go to Washington;people are even glad to see me.

But I am getting ahead of the story.Having convinced ourselves, at least, thatLAMPF was a great idea, the next step wasto approach the AEC. We worked out aproposal, and in January of ’63 I presentedan outline of it to the General AdvisoryCommittee and the President’s ScientificAdvisory Committee. Later in the year weforwarded a Schedule 44—a ConstructionProject Data Sheet—to the AEC. The Com-mission didn’t respond immediately by anymeans. They not only had to convincethemselves of the wisdom of spending somuch money in the then no man’s land ofmedium-energy physics, but also to chooseamong four proposals for a meson fac-tory—by Yale, Oak Ridge, UCLA, and us.They sought advice, and our proposal washelped by committee reports, especially thatof the Bethe Panel, that favored the idea of ameson factory and of a national facility inthis part of the country.

The Commission decided that ourproposal was the best one and in 1964 gaveus half a million dollars for design work. Weused part of it to dig the tunnel for themachine—not exactly the kosher thing todo. But we were not home free yet. Forseveral years we faced almost constant un-certainty about whether Congress wouldcontinue support of the design effort, letalone fund full construction. But designmoney did continue to flow and was put togood use. We developed a new and veryadvantageous cavity scheme for the ac-celerator, contracted for architectural andengineering work on the buildings, con-structed a home for prototype systems, andmade considerable progress on the rf system.

Finally, the AEC included in its fiscal year1968 budget the full remaining amount ofconstruction money. But Congress, whichhas been tremendously supportive ofLAMPF, followed the procedure of dolingthe money out in installments to permitannual reviews of cost and progress. Over

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the years this funding procedure causeduncertainty and some frustration.

The official groundbreaking took place inthe auditorium of the Administration Build-ing in February of ‘68—the weather didn’tcooperate—and only a little more than fouryears later the first trickle of 800-MeVprotons came down the line. Then in Augustof ’73 we saw our first mesons. Not only hadthe original proposal been realized, on timeand only very slightly over budget, but wehad also already begun to upgrade thefacility. We had received additional fundingfor the high-resolution proton spectrometerand had provided for the beam lines forresearch with neutrons and neutrinos and fortreatment of cancer with pions.

Since 1973 an impressive amount of basicresearch has been carried out at LAMPF.Let me tell you a little about some of thecurrent experiments and the scientificmotivation behind them. Of fundamentalimportance are the studies of the interactionsbetween nucleons—protons and neutrons.The measured properties of these interac-tions are clues to the nature of the strongnuclear force. To sort out the spin de-pendence of the strong force, the interactionsare studied at various relative alignments ofthe nucleon spins by using polarized protonor neutron beams and polarized targets.

Once the strong force is understood, itmay be possible to develop a theory that canpredict in very fine detail the structure anddynamic behavior of a collection ofnucleons—a nucleus. In the meantime theseproperties are being measured. For both theground and excited states, the distribution ofnuclear matter is investigated with protons,charge distributions and magnetic momentsare studied with muons, and the proton andneutron distributions can be separated. tosome extent, with positive and negativepions. In the field of nuclear dynamics. arecent experiment has demonstrated for thefirst time the existence of the so-calledisovector giant monopole resonance. In thissimple mode of motion, which had been

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February 14, 1968. At the LAMPF construction site the podium and bleachers erectedfor the groundbreaking ceremony stood deserted and snow-covered. Meanwhile, in theLaboratory’s Administration Building, New Mexico Senator Clinton P. Anderson(left), AEC Chairman Glenn Seaborg (center), and Louis Rosen attacked a box ofsand hastily substituted for the hard ground of the site. Appreciation for SenatorAnderson’s great help in making LAMPF a reality was acknowledged by formallynaming the facility in his honor in 1972.

predicted many years ago, the neutron andproton distributions expand and contractseparately along the nuclear radius, givingrise to nuclear density oscillations. Thisresonance has now been observed in tin- 120.The energy and width of the resonance tell ussomething about the compressibility of nu-clear matter. This parameter is important inastrophysics as well as in nuclear physics.

LAMPF is also the site of numerousexperiments in particle physics that dealmainly with the weak nuclear force. Underway now is an experiment to measure theproperties of the scattering between electronsand electron neutrinos. This information will

help pin down the mathematical structure ofthe theory unifying the electromagnetic andweak forces. Coming soon is a search fordecays of the muon in which muon numberor lepton number is not conserved. Theunified electroweak theory predicts thatthese conservation laws are not absolute, andso does the most credible of the theoriesunifying the electromagnetic, the weak, andthe strong forces. The measured probabilityof these decays, or at least better limits ontheir absence, will be of considerable interestto theoreticians.

To conclude this brief and incompletesketch of basic research at LAMPF, let me


LAMPF

The location chosen for LAMPF, Mesita de Los Alamos, wasone of the finger-like mesas extending eastward from the mainLaboratory and town sites. Scattered on most of these mesasare ruins of pre-Columbian Indian settlements. Informationabout the ruins on Mesita de Los Alamos was preserved byarcheological studies conducted before construction began.This aerial photograph of 1969 shows the mesa when excava-tion for the facility was nearly complete. Clearly visible in thecenter is the tunnel for the accelerator. West of the tunnel,toward the Jemez Mountains, are sites for laboratory andoffice structures and the injector system. East of the tunnel isthe site of the main experimental area.

No one can mistake the delight and satisfaction on the faces ofthose watching the instruments that told in June 1972 ofachieving the design beam energy. News of the event wasquickly proclaimed in monumental style along the road toLAMPF.

The LAMPF accelerator consists of three consecutive ac-celerators: a Cockcroft-Walton preaccelerator that provides abeam of 0.75 MeV protons: a drift-tube (Alvarez) linac thatincreases the proton energy to 100 MeV; and, shown herebeing tuned, a side-coupled cavity linac that increases theproton energy to a maximum of 800 MeV. The side-coupledcavity linac was conceived and developed by Los Alamosscientists. Compared to earlier designs, the side-coupled cavityscheme reduces the length of a linear accelerator by a factor of2.

LOS ALAMOS SCIENCE Winter/Spring 1983 59

Radiobiology andTherapy Research

Facility

The beam of energetic protons produced by LAMPF’s half protons with the targets, and the protons themselves, are usedmile-long linear accelerator is routed to many targets and as probes to investigate the world on a nuclear scale.experimental areas. The particles created by interaction of the

60 Winter/Spring 1983 LOS ALAMOS SCIENCE

LAMPF

The high-resolution proton spectrometer, perhaps the physically most impressivescientific tool at LAMPF, is shown here near completion in 1975. The instrument ishoused within a 46-foot-radius hemispherical dome, which is covered by a minimum of12 feet of earth for radiation containment. A specially tailored proton beam enters thetarget chamber (center) from the left. After interacting with the target, the scatteredprotons (or other particles that may be formed) are guided magnetically in a verticalplane to detectors positioned at the upper level of the superstructure. For protons withenergies in the vicinity of 800 million electron volts, the spectrometer can resolve anenergy difference as small as 60 thousand electron volts. To investigate the angulardependence of the proton-target interaction, the spectrometer can be rotated as awhole about the target chamber. A wide variety of research in nuclear and particlephysics is performed with the spectrometer, including studies of elastic and inelasticscattering between protons and nuclei, of particle-pickup reactions such as (p,d) and(p,t), of pion-production reactions leading to discrete final states in the residualnucleus, and of the fundamental nucleon-nucleon interaction.


mention the Weapons Neutron ResearchFacility. Its high-intensity neutron pulses areused, of course, for weapons-related researchand also for investigating the microstructureof matter. Neutrons are a marvelous supple-ment to x rays in solid-state physics becausethey make it possible to “see” the arrange-ment of hydrogen atoms.

The particles produced at LAMPF havemore practical applications as well. Anoutstanding example is the pion therapyprogram carried out at the Biomedical Fa-cility in cooperation with the University ofNew Mexico Medical School. To date about250 patients have received therapy. We arenot treating patients at the moment. how-

ever. because UNM does not have an emi-nent therapist to run the program. This hasbeen a great disappointment to me. UNM ishard at work trying to attract an appropriateprincipal investigator, and we are helpingthem as much as we can. If they determinethat they can’t restart the program, we willtry other ways.

Another practical application is the pro-duction of radioactive isotopes with theresidual proton beam. The isotopes. most ofwhich decay by positron emission or electroncapture. are being used as tracers in a varietyof medical and biological studies. During thepast year radioisotopes were shipped toabout fifty research groups.

We have also been successful in transfer-ring technology to the private sector. Let mepoint out first that all megavoltage radiation-therapy machines built in the United Statesuse the accelerator structure developed herefor LAMPF. Another example is a device fortreating superficial tumors, such as cancereye in cattle, by inducing hyperthermia withradio-frequency energy. One of our radio-frequency experts developed the device afterthe accelerator was completed. A number ofcompanies in this country are manufacturingunits for sale here and abroad, and similartechnology is being investigated at a numberof eye institutes as a means for changing the

curvature of the eye. The Chinese are ex-perimenting with the device on humantumors, particularly certain types of braintumor for which surgery is not feasible. Ireceived a report about this application dur-ing Mary’s and my visit to China in 1981. A

Chinese scientist told us, “We have receivedyour device in Shanghai, and I want to thankyou for this collaboration, ” I was quiteimpressed by this example of LAMPF’sinternational impact, which promises soon tobe even greater because the Department ofEnergy has recently decided to allow twoChinese scientists to spend a year atLAMPF. Here they will interact with peoplefrom many nations. What better way is thereto foster international cooperation and un-derstanding?

It must be fairly obvious that I have thesame pride and joy in LAMPF that parentsdo in their children. I have watched it growinto its position of pre-eminence and do notwant to see it grow old and uninterestingbefore its time. I believe that the projectsnow under way. such as the proton storagering. the time-of-flight magnetic spec-trometer. and the low-energy pion spec-trometer, should maintain LAMPF’s staturethrough this decade. We are planning nowfor a major upgrade—LAMPF 11. the kaonfactory—that, if it comes to pass, shouldtake care of the next decade. Then we muststart thinking about 2001.

Before relinquishing my soapbox, I want

to emphasize one thing very strongly.LAMPF was a very great technologicalgamble. There was a good possibility thatwhat we had proposed wouldn’t work. Wereit not for the fact that we were able, partly bydesign and partly by accident, to assemblehere one of the most competent and dedi-cated groups of people I have ever seenanywhere in the world, the idea would haveended in failure. We had set ourselves a verydifficult goal: accelerating a protonbeam—actually two beams simultane-ously—at intensities never before achieved.The intensities are so high that if more than

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For most LAMPF users a trailer is home away from home while an experiment is inprogress. This recent aerial photo shows many such trailers clustered aroundLAMPF’s main experimental area. The trailers house equipment for collecting andanalyzing data during the precious hours of allotted beam time.

In a pilot experimental program at LAMPF’s Biomedical Facility, about 250 patientswere treated with negative pions for a variety of advanced deep-seated tumors.Compared to conventional x-ray therapy, pion therapy is expected to provide improveddose [focalization and biological effectiveness. Shown positioning a patient under thepion radiotherapy beam are (left to right) Dr. Morton Kligerman, former Director ofthe University of New Mexico’s Cancer Research and Treatment Center, a visitingradiotherapist from Japan, and Dr. Steven Bush, formerly of the University of NewMexico. The hardware at the upper right includes a beam collimator, a dose monitor,and a device for changing the penetration depth of the pions.


LAMPF

Because the targets and other objects struck by the proton beam become extremelyradioactive, maintenance, repair, or replacement of these items must be carried out byremote control. LAMPF’S remote handling system includes a slave unit shown herenear a target cell (hidden within the shielding at the right). The crane positions themanipulator near the work area. Also visible are television cameras that provide theonly view of the manipulator in operation. A master manipulator controls the slaveunit from a nearby trailer, which also houses the television monitors and variouscamera and crane controls.

1 per cent of the beam goes astray, you

make the structures along the beam line soradioactive that they can’t be maintained orrepaired. It’s no trick to accelerate chargedparticles, but accelerating them with suchsmall loss is very tricky indeed. No onecould guarantee it could be done, and, infact, people who really knew the game werebetting we would fail. No one had achieved atransmission of 99 per cent through a half-mile-long machine because charged particlesrepel each other. They don’t want to go all ina straight line, they want to separate, to


diverge, and then they will interact with thestructures. We had to devise, from very firstprinciples, focusing and beam diagnostictechniques to control the stability of thebeam. Now it seems so easy—we start abeam at the injector, and a half mile down itcan be one millimeter in diameter. Onemillimeter. We had to develop a most basicunderstanding of beam dynamics to achievethis, and there are some interactions, somecouplings between radial and longitudinaloscillations, that are hellishly hard to predict,even today.

That was the biggest problem, getting thebeam out of the machine with such a smallloss. Once we solved that problem, we facedanother. A main purpose of the beam was tomake pions. To do that, you put a target infront of the beam. When the beam interactswith the target, all kinds of particles andradiations break loose. The volume aroundthe target becomes so radioactive that hu-man access to the area is forbidden for avery long time, Even with the machine off,the radiation level in the target is tens of

thousands of roentgens per hour, We knewthen. and we know even better now, that nomatter how perfectly something is made, it isgoing to break sometime and will have to befixed. How do you fix it if you can’t get to itand work on it? With remote maintenance.But nobody had ever tried to do remotemaintenance on systems so delicate and sointricate as the water and vacuum andelectrical and magnetic systems in a targetcell. And it was fairly certain that thesesystems would need repair sooner or later.The target rotates on bearings—to distributedissipation of the beam power—and is ex-posed to enormous radiation and extremeheat cycling. We didn’t know, and there wasno way to find out, whether we would startup the machine, run it at high intensity for amonth, two months, three months, only tohave something in the target break. Whatwould happen if we couldn’t fix it? We wouldhave had to bury it; that was in the cards.

But you have to have faith and you haveto have courage—this game is not for the

faint of heart. You have to realize that ifthings go badly, your name is going to bemud, and you may have to go some placeand live out your life without ever seeingyour colleagues again. It takes people ofextraordinary courage to stake their scien-tific future, their professional careers, onsomething that is really very risky. Butpeople do it all the time; they take thegamble and they may lose. But unless youtake these gambles, you can never win. Ithink we have won our gamble. ■

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Documents

The Clinton P. Anderson Meson Physics Facility, familiarly