STANFORD LINEAR ACCELERATOR CENTER JUNE 11,1970

irst Slac RetireeBy Ruth Paya

Jack Goad, long-time employee inIanufacturing and Fabrication's Light/achine Shop, retired from SLAG on the!8th day of May. On that date, auncheon honoring the event, andncidentally Jack's 65th birthday, wasleld by MFS Shops at the Red Cottagerestaurant in Menlo Park.

Mr. Goad had worked as a machinistmd tool and die maker for the past fiftyrears. He is originally fom Arkansas butn 1920 he made his way to the West?oast where he became an apprentice

nachinist. His salary, his recalls, was310.44 a week - with the promise of aour cents an hour raise every six months.

During these fifty productive years,lack Goad held several interesting jobs,me of which was with the Internationalrotalizer Company. This firmnanufactured and distributed mechanical;quipment used by race tracks- tote)oards, time clocks and ticket machines.For eight years Jack was Service Manager'or the firm visiting field installations atracks (for both dog and horse racing) in)regon, Colorado and Arizona. DuringVorld War II, the company convertedemporarily to the production of

)recision tools and equipment for thelefense effort.

Jack remembers his years with this:ompany very fondly, but he also workedit some firms in the immediate Peninsulairea. He spent fifteen years as a shop!oreman and manager in the Bay Areatutomotive industry as well as eight years

)f supervising at Dalmo-Victor and fivenore at Philco-Ford as a supervisor3efore coming to SLAG. He was in his;ighth year with Stanford.

Jack has been, by his own proud;tatement, "happily married for 42rears" - an enviable record. He has twoFrown sons, both married and both;ergeants in law enforcement. One is with;he San Mateo County Sheriff's officemnd the other with the San Francisco.?olice Department. Both sons were thejoungest men ever to be appointed to;ergeant in their respective jobs. Jack'samily also includes three granddaughters.

Over the years Jack has done his share>f community service. He is a member of;he Masonic Lodge and did his stint as a-ub master with the Boy Scouts. He also;erved as a Red Cross First Aid Instructor:or many years for local groups of Boyscouts and the Police Department.

Almong his favorite sports he includesiunting and fishing. He hopes, upon:etirement, to indulge in these more)ften. He aid his wife (who retires fromLenkurt Electric next month) plan tomove to a place they own in Grass Valley.

Continued to Back Page

'roject Leapfrog'Off The Ground

In keeping with its policy ofinnovating for the future, SLAG has beeninvestigating the possibility of building a100 billion electron volt (100 Gev)superconducting accelerator. This project,which would cost roughly 66 to 78million 1969 dollars and require sevenyears after technical feasibility had beenestablished for completion, couldenhance SLAC's experimental capabilityin a number of ways. The increasedenergy would open up new areas ofinvestigation using electron and photonbeams and beams of secondary particles(pi mesons, K mesons, etc.). Thehoped-for capability of the new machineto accelerate electrons continuously at 25Gev (100% dutycycle) and to a 6% dutycycle at 100 Gev is another significantadvance when these numbers arecompared to the current duty cycle ofless than 0.06%. (Duty cycle is thepercentage of the time beam is beingaccelerated.)

The fundamental "pencil and paper"investigations going on over the past yearand a half are now being augmented by a"brute force" project to build a 50centimeter (20 inch) superconductingaccelerator capable of producing a 17million electron volt (MeV) electronbeam. This endeavor is called "ProjectLeapfrog," since the idea is to "leapover" a systematic and thoroughinvestigation of the properties ofsuperconducting niobium and ofengineering and fabrication problems andto proceed directly to the construction ofan operating device.

Stage I of the project involvesconstruction of the unit without anelectron beam. This will occupy most ofcalendar year 1970. Stage II is operationwith beam. This stage will occupyroughly the first nine months of 1971.

Why use superconductivity to increaseenergy? What is superconductivity? Toanswer the second question first,superconductivity is the phenomenonwhereby certain metals lose all theirresistance to the flow of electricity whenthey've been cooled to within a fewdegrees of the absolute zero oftemperature (-460°F). It is this propertyof superconductors which answers thefirst question: If less power is lost to theelectrical resistance in the walls of anaccelerator, instead of pulsing theaccelerator it's then possible to leave thepower on continuously and hence toaccelerate electrons continuously (100%duty cycle). In addition, measurementson small niobium test cavities indicatethat it may also be possible to increasethe energy by a factor of 3 to 5 over thatattainable with a conventional electronlinac.

To illustrate, SLAG at present hasresistive energy losses in its copperaccelerator of millions of watts perten-foot section. When the newaccelerator is operating at 25 GeV thesuperconducting structure woulddissipate only twelve watts per ten feetless than one, one-hundred thousandth asmuch as the present SLAG structure.

The Leapfrog accelerator (and,ultimately, the 100 GeV machine) will bemade out of niobium metal andsupercooling will be provided by a liquid

Continued to Back Page

Photo of apparatus used in muon scattering experiment.

Inelastic MuonExperim ent at Slac

By Steve Kociol

In last month's SLAG NEWS weoutlined some properties of one ofnature's most mystifying particles - themuon. This article will continue thediscussion.

SLAC's Group E physicists are thelocal muon experts and, in the course of afar-reaching experimental program, havecompleted the world's first study ofinelastic muon scattering from hydrogen.Inelastic scattering occurs when theincoming projectile (beam particle)imparts a significant fraction of its energyto a target particle. In this case, muonswere the projectiles and protons thetarget. The experiment was undertakenmainly to investigate possiblemuon-electron differences, but otherprocesses were also of interest.

In order to do muon physics, it'snecessary to have a nice coherent beam ofmuons to work with. SLAC, being anelectron accelerator, is able to produceintense fluxes of muons and, under thedirection of M. L. Peri, Group E decidedto build such a beam.

Why is SLAC much more effective inproducing muons than, say, a protonmachine like the one at BrookhavenNational Laboratory, on Long Island?The reason is that muons aren't produceddirectly when a high energy proton hits atarget. Instead, charged pi mesons (pions)are produced. They live about 26billionths of a second and then decay intoa muon and a neutrino. So, with a protonmachine, the muon source is pion decayand since all the pions don't decay at thesame point, the source may be over 150feet long. This leads to a muon beam oflarge diameter, large angular spread, andlarge energy spread. All of this is bad,from the experimenters point of view.

But at SLAC, muons are produceddirectly when the electron beam goesthrough a 5.7-inch long copper target.This copper muon source actuallyproduces 70% muons with 30% pioncontamination. This contamination turnsout not to be much of a problem sincealmost all of the pions can be filtered'outby passing the pi-mu mixture through 18feet of beryllium. After this filter, there is

only one pion for every 300,000 muons(on the average).

In the end, the muon source appears asa one-inch diameter disc - a distinctimprovement over the 150-foot longcylindrical source of the proton machine.The beam diameter, angular spread, andenergy spread of particles within thebeam can be kept small. All of this isgood.

But there is a kicker. At theBrookhaven proton synchrotron thebeam is on about 25% of the time. Thisamounts to about 22,000 seconds ofbeam per day. At SLAC there are onlyabout 22 seconds of beam per day. (Inone second of operation, an experimentmay receive 180 pulses of electrons, eachlasting only 1.4 millionths of a second. Sothe fraction of the time beam is beingaccelerated equals 180 times .0000014 or.025% Since there are 86,400 seconds perday, this gives 21.6 seconds of beam perday. Physicists say that SLAG has a low"duty cycle.") The result of this is that itis necessary to run 1000 times moreparticles (per apparatus resolving time),making life more difficult.

Several experiments besides inelasticmuon scattering were carried out usingthis beam. Group "E" measured particlefluxes, searched for new particles andlooked for quarks (with a group fromHEPL). Visitors to SLAG (University ofWashington) studied muon scatteringfrom electrons.

Now that we have a beam of muons,how do we do an inelastic scatteringexperiment?

The apparatus which does the job isillustrated in the photograph andexplanatory drawing. It is necessary todirect the muon beam into a liquidhydrogen (proton) target and thenobserve the way those muons whichcollide with protons are deflected(scattered); that is, the angle of scatterand the final energy of the scatteredmuon. These data allow calculations ofthe important results of the experiment,namely the probability that a muon willbe scattered into a certain angledepending.upon its energy - the so-called

. Continued to Back Page

VOL.1, NO. 4__ I_ _1____1_ �__ _III ---------·L_·P�--_-��-I·_-�- -I-�--·--_ -�l-----ll-----·-·-C-----�·s

A Big Hit.On May 20 and 21, the SLAC Choral

Group presented their latest productionin the Auditorium. Both performances of"A Thing Called Love" were met withwell-deserved cheers and applause fromthe audience.

Weeks of hard work and preparationwere involved in these performances andthe cast gave a lot of their leisure hours tothe numerous rehearsals required. SLAChas many talented individuals and we are,fortunate when some of them, such as theChoral Group, are willing to share their,good voices and musical ability with us.

At the beginning of the show the stagewas blacked out except for a spotlightdirected on Charlie Hoard of ME,narrator for the show. He opened withsome brief, humorous remarks about loveand spring and followed with a quotefrom Omar Khayyam. In 800 years, theGreat Tentmaker's poetry had lost noneof its wit or charm. The stage was then litup to show a background of blue sky andlacy white spring foliage; and, on stage,tables, bright-colored chairs, and pottedtrees and plants created the illusion of astreet cafe. The members of the choruscame on stage and seated themselvesabout the tables while they sang "What isThis Thing Called Love" - an old ColePorter favorite. Each succeeding numberwas then introduced in the same manneras the first. A full black-out, narrationand poetry quotes by Charlie Hoard, andthen an individual solo, duet or choruswas presented. Among the songs offeredby the chorus were "Love is the SweetestThing", "Love is Blue", and BertKaempfert's "L-O-V-E".

Polly Lea's solo "I Love You" againsta background of men's voices was veryeffective; and Evelyn Barnes and RondaDave, singing "Love is a Many-SplendoredThing" as a duet drew heavy applause.Later, Ronda sang another duet, this timewith Vernon Smith from ES - twoattractive people whose voices blendedvery pleasantly.

Hunor for the show was supplied byCharlie Hoard's rendition of the lovepoetry used, and by DeeDee Mayes andBob Laughead in a burlesqued version ofthe song "Temptation". DeeDee started itoff by playing some heavily schmaltzychords which she abruptly broke off bysliding along the piano bench and joiningLaughead at the microphone. There, tothe accompaniment of much scarfswishing by DeeDee and a good deal ofcow-eyed ogling by Bob, they clownedtheir way through the song. At the line"You were born to be kissed...", DeeDeebegan an amorous attact on Bob thatbrought down the house.

The whole production waslight-hearted and fast-paced and all theparticipants seemed to enjoy their showas much as the audience did. DeeDeeMayes, as producer and writer deservesparticular credit. She also acted as pianistfor all the numbers as well as presentingEdvard Grieg's "Ich Liebe Dich" as apiano solo. The other musicians wereFrank Noga on tenor guitar and TedSyrett on bass guitar. Additional credits:

Craft Shops' PicnicOn Saturday, June 20th, Craft Shops

will have their annual picnic. This yearthey are holding it at the Palo Alto Elks.Club which has an attractive picnic area.Located behind the club, off El Camino,there are five acres of deluxe picnic,grounds with a pool for swimming alsoavailable.

The menu for the day includes steak,salads, garlic bread, corn on the cob andtraditional items such as hamburgers andhot dogs. There will also be ice cream andvarious beverages available - all for atoken price of apprqximately $2.00 foradults and $1.00 for children.

Don Ewings, who is in charge ofarrangements, indicates that all of thePlant Engineering Group (of which CraftShops is a part) are invited. They maybring guests if they desire, andreservations can be made by calling CraftShops on extension 2371.

Special features of the picnic willinclude door prizes for both adults andchildren, as well as entertainment, gamesand prizes for all.

Want AdsCHILD CARE: Stanford Community

Children's Center extends its summerday-care program to include 5-8 yrolds, 6/15 -9/4. Full and part-day careavailable. Call 327-7814 anytime.

BABY CLOTHES: Wanted to fit child 6mo. to 2 yrs. Also, "Baby Bouncer."Call Wendy, ext. 2216; 854-6086 eves.

FOR RENT: Small, secluded cabin, idealfor recreation or retreat, Del MonteForest, Carmel. Available$40/weekend. Call Mike Menke, ext.2775 or 941-2093.

FOR SALE: German Shepherd puppies,black & tan, 8 weeks, large. Call JohnHotchkiss, ext. 2486/ 2487.

READER WANTED: For visuallyhandicapped person. Level, aboutScientific American. Few hours aweek, on tape or in person. CallCharles Oxley, ext. 2204.

Property & Staging, Ronda Dave, ADA;Lights, Willie Johnson, EB; Scenery, (Art)George Lee, ME and (Carpentry) GeorgePetri, PE; Posters, Susan Reupke, MED;Photography, Walter Zawojski, PUB;Publicity, Ruth Paya, MFS; and ProgramCover, George Lee.

Donations for SERA, SLAC'sEmergency Relief Association, werecollected in the lobby, and were laterpresented by the Choral Group to SERAas an addition to the Association's funds.

The Choral Group will take atemporary break during the -vacationmonths but hope to present another showin the Fall. They also plan to prepare theannual Christmas Show. Anyone whowould like to participate will be given anopportunity at that time. Watch yourSLAC NEWS for further announcementsconcerning this;

SLAC DictionaryELEMENTARY say two different particles states(L ELEMENTAR. C. rf\ 1^ I Y communicate if they have the same values

Ed A E] T I /" I 1 for spin, atomic number, and some otherPr A I C L E quantites, although not necessarily mass.

In this scheme, a given particle isThe next term to be defined in the generated by lots of other particles and.

SLAC dictionary is a controversial one - in turn, helps generate them."elementary particle". What is an Zemach finally notes that even ifelementary particle? In what sense, if compositeness is accepted, elementaryany, is it elementary? Does elementary in particles can still be distinguished asany sense imply fundamental? having large binding energies as compared

W.K.H. Panofsky, in his chapters on with the energies of their constituents."Particle Physics," (written in All of this is discussed in the followingcollaboration with Oxford theorist R.H. statement by SLAC Deputy Director, SidDalitz and published in Nuclear Energy Drell:Today and Tomorrow) notes that the "There does not exist at this time aquestion of whether or not the satisfactory definition of an"indivisible" exists was first asked by elementary particle in fundamentalThales of Miletus around 580 B.C. terms.Democritus, a century later, said that "In a purely descriptive language wEreality itself is composed of many kinds say that the elementary particles arsof particles which are never annihilated. the building blocks from which allIn 1911 Rutherford proved that atoms matter, living and dead, is made. Atconsist of a very small positive nucleus one time molecules, then atoms, thersurrounded by negative electrons. electrons, and nuclei, and more

At present it is known that all atoms recently electrons, neutrinos, p:are made up of neutrons and protons, mesons, and protons have beerwhich determine the nucleus, and candidates for these building blockselectrons. We might be tempted to say an By now so many cousins or other closeelectron is an elementary particle but a relatives of the pi mesons and proton!Uranium atom isn't, simply becuase it is have been produced at high energymade up of electrons, protons and accelerators that we can do little moreneutrons - in a word, it is a composite than group them into families thaistructure. Likewise, molecules are groups exhibit similar behaviors under similaiof atoms. conditions. In this way we can orde]

But how does this relate to the the phenomena but we no longer loolwell-over 100 short-lived subnuclear to each of these family members a,particles produced in accelerators or by being elementary particles. We muctcosmic rays which we've observed. prefer to hope that these very largeThey're certainly not atoms or molecules. and extensive families can themselvesThe physicists Lee and Yang give this be built up out of a few constituent,operational definition which includes ("quarks"; "Partons";?) just as all oJsubnuclear particles: the world's many thousands o]

"We believe we understand what is different kinds of molecules and atom!meant by an atom, a molecule, and a can be constructed simply froirnucleus. Any small particle which is electrons, protons and neutrons alonenot an atom, not a molecule, not a The big trouble so far has been thatnucleus (except the hydrogen nucleus) Nature very effectively hides theseis called an elementary particle." constituents from us, if indeed they

This, of course, is a working definition exist! She does this by having theirand does not imply that there be interact with one another by verbanything fundamental about the particles. strong forces. Thus when we "loot

SLAC's J.D. Bjorken thinks the Lee into an atom" we can pretty well seeand Yang definition is a good one, but the electron because it is almost freebelieves an improvement might be: However the energies binding togethe"electrons, protons, neutrons, photons, the constituents forming a protrorand all other metastable states of matter whatever they may be, are hundreds ol(excluding nuclei, atoms, molecules) millions of times stronger - exceedingformed by collisions between them." This those binding the atomic electron jusidefinition does away with the vague as do the energies released b5adjective "small" and incorporates the hydrogen bombs exceed the energiesfact that particles like pions, muons, etc. released by sticks of TNT or chemicaare observed after being formed by fires. Thus these constituents are nolcollisions. readily seen when we "look into -

Charles Zemach of SLAC's theoretical proton" because of the influence olgroup connects the ideas of elementary these very strong forces and we don'sparticle and fundamental understanding know what one of them would loolby noting that the explanation for their like if seen alone and all by itself. Thaiexistence probably stands at the is why we cannot answer at this tim(beginning of a deductive explanation of solely in terms of observables and witt~the properties of all matter. He also precision: "An elementary particle-brings out the distinction between is ...." But maybe the next experimen"non-composite" and "elementary." The or the next accelerator will provide Xso-called bootstrap theory opposes the crucial clue!"notion that the two terms are So here we have the views of a numbesynonomous. Very roughly, the bootstrap of physicists on what an elementarhypothesis considers each particle particle is. The attempt to find this out iparticipating in the nuclear force to be a the very reason for the existence of higlfound state of all the particle states with energy accelerator facilities such awhich it can "communicate." Here, we SLAC, and provides for job security!

Distaff Club FlingStanford's Distaff Club, which

includes a number of SLAC ladies, ishaving their SPRING FLING, on Fridayevening, June 12th, at Holbrook-PalmerPark on Watkins Avenue in Atherton.Sara Butler of the Controller's Office isPublicity Chairman for the event, and sheannounces that there will be an elegantwine tasting session starting at 6:30, withan excellent dinner following at 7:30.They will have strolling musicians duringthe wine tasting hour and music, singing,

and other entertainment during thdinner.

The cost per person for the event i$4.00, and the deadline for reservations iimmediate because of the lateness of thiissue of the NEWS. Call Ruth Kaise]Women's Gym, extension 8-4895, or Sarat extension 8-4195, if you are presentla Distaff member and wish to attend thifunction or if you would like to becomemember of the Club and have this serve Eyour introduction to their many activitie

-

Slac Soccer TeamSocks It To 'Erm!

By Roger CoombesIn the spring of 1968 George

Cruickshank of MFS, who had playedprofessional soccer in Scotland, and SamStevens, then at SLAC, and an allAmerican player at Stanford a few yearsbefore, organized some after-work soccerpractices.

Soon there were enough players tomake up a team and the SLAC SoccerClub was formed. The first season wasvery successful and the team won most ofits games, including beating the StanfordVarsity Team. There was talk then ofentering a team in the Peninsula SoccerLeague (PSL) and playing in more seriouscompetition. This idea was dropped,however, since it was not compatible withthe Soccer Club principle of enabling thelargest possible number of people toparticipate (only 4 substitutes are allowedin PSL games). The club thus took on itspresent form, fielding an off-season teamthat is active only through the summermonths. These matches are played afterworking hours in the evening.

Anyone associated with SLAC iswelcome to join the club even if theyhave never played soccer before. We havepractices and training sessions and duringmatches make frequent substitutions sothat everyone has a chance to play. Weplay against several local teams, such asGus Mozart, General Electric, Wilbur,Syntex, etc., with the matches generallystarting at about 5:30 on the StanfordSoccer Field.

During the 1969-70 PSL season, ErnieFrei of ME and MFS, coached theFairchild League team and three playersfrom SLAC played on that team. Thisopening remains available to any SLACplayers who wish to play regularly duringthe winter. The team tied for first placein the Third Division of tie PSL but lostthe play-off game. One of the players,George Cruickshank, also plays for theScots in the San Francisco league. Thatteam is consistently at or near the top ofthe first division with that league and oneof the strongest teams in California.

The 1970 season got off to a bang!The first game was played on theStanford Soccer Field on campus, as areall games, and was against the Gus Mozartteam. SLAC won 6-2! Our second gamewas with Holt Tool and Die Companyand we sequaked by them with a score of2-1. The next game will be at 5:30 onJune 10th against Syntex, and the gamefollowing that will be with a "pickup"team of Stanford noon players on June17th, also at 5:30. Several other matcheswill be scheduled for the weeks followingthat.

If you would like to play, come andjoin us. Tennis shoes are fine - if youlearn to kick properly (important if youhave a high pain threshhold!). If youwould like to watch, come and root forus; or, if you're not interested in soccer,meet us in the Oasis in Menlo Park afterthe game - and help us with the mostimportant function of all!

Engineer Re-ElectedKeith W. Henderson, Accelerator

Electronics, has been re-elected for athird term as a director of the NationalSociety of Professional Engineers.

The society's Peninsula Chapter hasawarded him its Member-of-the-Yearcertivicate this year, in recognition ofmore than a decade of outstanding anddedicated all-around service to theengineering profession.

Keith formerly served as secretary,vice-president, and president of thechapter, and as a director of theCalifornia state society. He also foundedthe chapter's monthly bulletin, thePENINSULA PROFESSIONALENGINEER, and has served as itsmanaging editor for more than ten years.

Diamonds Play VtalRole In Experiment

By Charles OxleyBe they square cut or round cut,

"diamonds are a girl's best friend." Andin the production of high qualitypolarized gamma rays, using diamondscomplements the use of laser beams.

With both diamonds and lasers, thereis a similarity to the sound waveproduced by a boy running a stick along apicket fence, the stick being a high energyelectron. The pickets are the atomsregularly arranged in the diamond. Or forthe laser beam, they are the wavestructure of the light itself. The idea hereis to produce a coherent wave of energy.

In the case of the laser beam (asdiscussed in the first issue of SLACNEWS), the light is automatically ofexcellent quality and coherence. Withdiamonds, however, girl appeal or gemquality is not enough. A single crystal ofvery regular structure is required. After avery special search, the diamonds to beplaced in our electron beam as a means ofproducing a photon beam were found byRoy Schwitters, Lou Osborne, Joe Leongand Dave Luckey, all of MIT. Theyconsulted experts on diamond physics,but were not given much encouragementor guidance, so they ended up bydeveloping criteria as they went along.For examining the perfection of uncutdiamonds, they used the double x-rayspectrometer at the National Bureau ofStandards. Drawing on the stock of HarryWinston, the New York diamond dealer,and sources in the Netherlands, theyfound two excellent diamonds. Two sliceswere cut from a four-carat diamond, andone from the other. Curiously enough,these very perfect single crystals are ofmarginal gem quality and contain somenitrogen impurity. This may havecontributed to their preservation bystrengthening them against geologicalforces.

Production of high energy photons(also called gamma or x-rays) from highenergy electrons does not occurspontaneously in a vacuum, but requiresacceleration of the electron. In theprocess known as "bremsstrahlung,"(German for braking radiation), the forceof acceleration is usually furnished by theelectric field of an atomic nucleus. As theelectron interacts, a photon or gamma rayis emitted, and the nucleus recoils.Convervation of energy and momentumrestrict the possibilities for the velocitiesinvolved and also the energy of thegamma ray.

Rather surprisingly, the wholediamond crystal can take up the recoil athigh energies. Due to relativistic effects,recoil becomes less and is more easilytaken up by the crystal withoutdisruptive effects. The process ofcooperative enhancement by action ofthe whole crystal is known as coherentbremsstrahlung. The orientation of thediamond crystal with respect to theelectron beam critically affects theradiation.

The crystal brought to SLAC by theMIT group is mounted in double gimbelsin a goniometer arrangement. Agoniometer is a device for measuringcrystal angles. The angles are adjustableand are critical to a few seconds of arc.The diamond crystal is about 1/4-inchsquare by 1/16-inch thick. Thegoniometer was designed and built byMIT for SLAC and will remain here.

The spectrum of gamma ray energiesproduced in a narrow beam rises from alow value at low energies to a peak with asharp drop-off and some small structureabove the drop-off energy.

The sharp cutoff can be used to highadvantage in the experiment set up by theMIT group, and Adam Boyarski, StanEcklund and Bob Siemann of SLAC. Thestudy is of single positive pionphotoproduction from hydrogen. Thepions produced are analyzed in the 20GeV, 1700 ton, magnetic spectrometer in

UICK Loiiins tunes-in at SLAL Station VVAINUIr.

Amateur Radio Club In Full SwingOn January 4, 1970, Dick Collins of

the Klystron Group was listening to the15-meter amateur-band radio in theSLAC Radio Club station under theCentral Control Building when he pickedup a call from Station 0A4F in Lima,Peru. The call was for a contact by phonepatch with a party in Mountain View,California. At the time, there waspolitical upheaval in Peru and normatcommercial channels of communicationwere not available.

Dick tuned his transmitter to thecalling frequency and answered. Thus aphone patch was set up between aworried family in Mountain View and afortunate person in Peru who had learnedhow amateur radio can be of service toprivate parties under unusualcircumstances. (Contact between SLACand Lima has been established againduring the current quake aftermath.)

The SLAC Radio Club, operatingStation WA6NUP, began in 1968 when aquestionaire was circulated to employeesrequesting interest in such a club. VicWaithman, Don Farwell, Ted Constant,(the first club president), Warren Struven,Jim Spitler, and Shorty Freitasspearheaded the planning. The responseshowed that there were enough licenseholders and others who wanted toparticipate to obtain licenses through theClub so that the matter was pushedforward. Funds were obtained from theSLAC recreation fund and a space wasfound in the basement of the CentralControl Building to house the station.Starting from a half-dozen people as anactive nucleus, the Club has grown to amembership of 55 and the station hasalmost full-power coverage of allocated

End Station A. The sharp cutoff in thegamma ray spectrum is reflected in thecounter-detected pions as displayed on acomputer output. Analysis can be madealmost equivalent to that obtained from amuch-sought after, mono-energeticgamma ray beam such as is produced herein positron annihilation or from theback-scattered laser light. %

The interest in redoing theoft-repeated meson production lies in itsstill poorly-understood dynamics. Thefact that the diamond-produced gammarays are highly polarized is their tellingquality.

Previous experiments have been doneat lower energies by groups at CambridgeElectron Accelerator, the GermanElectron Synchrotron, and in Japan.Also, an experiment here at SLAC with aUC Berkeley group using a polarizedproton target yielded somewhat differentdetailed information about the process.The present experiment uses the sameenergy as that experiment to bring fulllight on the process. A choice amongseveral theoretical models, each reflectingthe state of our ignorance, may bepossible when this experiment iscomplete.

amateur radio bands.Membership in the organization is

available to any interested SLACemployee and is obtained throughapplication to a Club officer. Besidesexcellent transmitting and receivingfacilities, the club has assembled a libraryon amateur radio, has test equipment forchecking components they mightassemble, and a code practice benchwhere code lessions are available atmultiple earphone outlets.

Current officers of the club are DickCollins, President, Ted Constant ofAccelerator Physics, Vice President, DonFarwell of RAD, Secretary, and WarrenStruven of Accelerator Physics, Trustee.Executive Committee Membe are FredCoffer, Klystron Group, 'Harry Saal,Physical Electronics, and Ron Baggs,Experimental Group E.

Amateur radio is licensed under theFederal Communications Commissionwith regulations designed to make bandsavailable to not only general hobby use,but for special emergency and disastercommunications. The most simple licensefor the beginner beyond the amateur'scitizens' band is a novice license whichrequires a capability of fivewords-per-minute Morse code andsufficient technical knowledge to keepthe operator within frequency allotments.The license is good for two years, whichshould allow the beginner time to becomeproficient enough to advance to thegeneral class license.

The novice license may be obtained byexamination from any licensed amateurgeneral class radio operator or higher. Theadvanced types of licenses require eitherincreased facility with Morse code or ademonstration of higher capability, orboth. With advanced licenses go extrapriviledges in allowable operatingfrequencies and power. Morse code isrequired of license holders because, underdifficult circumstances of reception orinterference, it has greatercommunication penetration.

The SLAC station operates mostlyduring the noon lunch period. Visitorswho go down the outside steps on theeast of CCR and find their way throughthe doors to the inner club "shack" willbe welcomed almost any noon hour. Thestation facilities are available to membersat other hours by contacting the CCR orone of the Club Officers when theControl Room is not manned.

SLAC NEWSStanford Linear Accelerator Center

,Jack Sanders ............ EditorSteve Kociol ..... Associate EditorWalter Zawojski .... Graphic Artist

Regular Contributors:Dr. Charles Oxley, PIO-Ruth Paya, MFS

Published bySLAC's Public Information Office

P.O. Box 4349, Stanford, Calif. 94305Telephone 415 854-3300, Ext. 2204

... . .. i....

- ~ ~~ ~ ~ .- _

T

I

SLAC PERSONALITY BerAnn Laura BergAnna Laura Berg is a SLAC secretary

working in Burton Richter'sExperimental Group C. This marks her27th year at Stanford.

Born in Pocatello, Idaho, Anna Laurawent to Logan, Utah to attend college atUtah State. There she obtained her B. S.degree in dietetics. Graduating during thedepression years, she was able to findwork as a dietitian for only one year afterwhich she had to see any job available.During that one year she conducted afamily living survey for the U. S.Department of Agriculture in the city ofLogan. Advised by the Department thatshe could hire a secretary from the WPArelief rolls, she made a request only to betold that depression or no, there were nosecretaries on relief. Secretaries were notin surplus. That should be an encouragingpiece of information for secretarieseverywhere.

About 1937, Anna Laura took a jobfor a year with the Utah Power Companyas a home service demonstrator. This

MII1/MA LAUIIRA tn3

involved showing farmers' wives how touse their newly purchased electricalappliances, and gave her a chance tobecome acquainted with a good deal ofrural Southern Idaho and Northern Utah.

Anna Laura held other jobs after that,most of them secretarial in nature, but bythe end of 1938 she had decided to cometo California. She recalls applying for herfirst job in Berkeley and insisting that shemust make $100 a month. Theemployment office told her theyconsidered this unreasonable - despiteher experience and a college degree. Sheheld out, however, and ended up with thepay she wanted on a job in nearbyEmeryville.

By 1940, Anna Laura had moved toPalo Alto where she applied for and got ajob at Stanford working for a professor ofEducation who, on his own, was doingpublic relations work in education. Then1941 brought Pearl Harbor and anotherchange. Anna Laura recalls her bosstelling her, "You have some vacationcoming...why not take it now and lookfor other work?" The very next day shelanded a job in the Graduate School ofBusiness where she worked as a Secretaryto Professor Paul Kirkpatrick, then actinghead of the Department of Physics. Thatwas the beginning of her long associationwith the physics profession.

Dipping into a vast store ofinformation concerning physics activitieshere at Stanford, Anna Laura came upwith some interesting notes. She told usthat the Physics Department, though wellknown, was quite small before World WarII. All the professors, except ProfessorKirkpatrick, and most of the regularstudents were either off to war orworking in defense. Al Baez, father of thethen 2- or 3-year old Joan Baez Harris,was one of the graduate students who wasalso an instructor in physics. In 1942-43the Department of Physics was requestedby the Army to instruct fifteen hundred

physics as part of the Army Specializedyoung men at Stanford in engineering and

Training Program. Classes ran from sevenin the morning until eleven at night andlabs and problem sessions were even heldon Sundays,which caused some complainton the part of the Stanford Church. AnnaLaura smiled as she recalled some of theemergency teachers' backgrounds. Therewere professors from the School ofEducation and the Department of Musicand from San Mateo and San Josecolleges. There were graduate studentsfrom Anatomy, Chemistry andMathematics. In fact, anyone who hadsuccessfully completed a course inphysics sometime in his past and who waswilling to contribute his time was pressedinto service. The students worked hard,however. Those failing the course endedup in the South Pacific in the infantry.

Although all of this was an interestingtime for Anna Laura, the really excitingpart of her association with Physics beganas the war ended. Students majoring inPhysics, graduate students and new ones,came flooding to the campus and beganthe major expansion of the Departmentand its program. Dr. Terman, nowProvost Emeritus, returned from theRadio Research Laboratory at Harvard,and brought with him several outstandingstudents. Others came from the RadiationLab at MIT and from Sperry (whereProfessor W.W. Hansen, for whom theHansen Labs are named, spent the waryears). From 1948 to 1966 Anna Lauralived on campus at Hacienda andcontinued with the Physics Department.She remembers that Professor Hansen'sgroup "worked on a shoe string" indeveloping the first accelerator in a tinyroom of the Physics Building basement.The space was so small there was barelyroom to fit the fledgling accelerator andits parts into the available space. In aroom nearby was a cot for helpers to reston as they worked through the nightimproving and expanding the accelerator,and Anna Laura sometimes contributedher time "holding voltage" and callingout the readings on the public addresssystem. I can still hear, she told us, Dr.Hansen saying "I know it's going towork!" And work it did, helped out bythe efforts of research students and Dr.Felix Bloch, first man-at Stanford toreceive the Nobel Award. Professor WillisLamb, now at Yale, and ProfessorHofstadter, still at Stanford, also receivedthe Nobel Award during her stay in theDepartment. Anna Laura recalls theseaward times as intensely excitingmoments since she was usually aware ofthe awards prior to their being madepublic but was sworn to secrecyconcerning them.

About 1962, Anna Laura left Physicstemporarily and spent four years-in theAsian Languages Department at Stanford.Here she picked up a continuing interestin the Chinese language and culture. Shestarted an evening class in MandarinChinese through adult evening highschool and is still taking lessons, currentlyon Wednesday nights at SLAC, under thedirection of Alex Tseng of the PlantEngineering Department. She is the onlynative American in the class. The othermembers number a Dutch man, a Frenchgirl, two Japanese scholars and twoChinese-American women.

Another outside interest is cooking,retained from her early years and whichprobably prompted her to major indietetics in college. She makes her ownbread and occasionally brings a cake towork to share with her co-workers.

Although she has no immediate plans,Anna Laura looks forward to having thetime and money to travel. First on herlist,, when that time comes, will beNorway, her father's homeland.Meanwhile Anna Laura Berg works in theCentral Lab in...yes, that's right, thePhysics section.

Muon ExperimentContinued from Page 1

scattering cross-section.The target consisted of about two

meters of liquid hydrogen. The smallmagnet following the target was used tosweep away obnoxious low-energyelectrons "liberated" in the target.Thin-plate spark chambers placed beforeand after the large-aperture magnettracked the scattered muon's trajectoryand the thick-plate chambers made sure itwas a muon which was being observed.Particles which participate in the nuclearforce, like pi mesons, are stopped quiterapidly in matter. To illustrate, a 10billion electron volt (1OGeV) pi mesonwill suffer a nuclear collision after passingthrough only 20 centimeters ofaluminum, while it takes 2000centimeters of aluminum to stop a 10GeV muon!

The final results of this experiment are

'Leapfrog'Continued from Page 1

helium jacket surrounding the disk-loadedniobium structure. Some majorparameters of Leapfrog are the same asenvisioned for the two-mile machine.These include klystron frequency (2856MHz), energy gain (30 MeV per meter),and klystron power 1640 watts permeter). The 50 cm of disk-loadedwaveguide differs from the presentcopper structure in internal shape as wellas material.

Getting back to the 2-mile machine, itwill be divided into 30 sectors as is thepresent accelerator. Each sector willconsist of sixteen, 20-foot acceleratorsections housed in a thirty-inch diametercryostat (helium tank and heat shield).Different klystrons will be used, but therewill still be one every 40 feet. Whilepresent klystrons have 20 to 30 millionwatts peak power capability, the tubes tobe used in the superconducting machinewill need peak capability of only 20thousand watts. These new klystrons willbe roughly 50% efficient in convertinginput power to radio power, comparedwith a typical efficiency now of 35 to40% for all tubes on the machine (SLAC'sown klystrons, however, are about 47%efficient).

It is anticipated that the use, to theextent possible, of existing facilities willresult in a cost savings of 10%.

How long would SLAC be off the airduring construction of the new two-milesuperconducting machine? Only twoyears! As mentioned earlier, seven yearswill be required after proof of feasibilityfor total conversion. The first two yearswill be devoted to preliminary design andtesting. During the next three years, finaldesigns would be fabricated and storedwhile the existing accelerator is operatingwith a full schedule. During the sixthyear, operation of the existing machinewould cease and hardware installationtake place. The seventh year wouldinvolve checkout and testing. Theexperimental program would then be ableto begin.

For more detailed technicalinformation on this fascinating project,see SLAC Publication 749 (June 1970).

still being worked on. The mostunexpected result so far was a muchbigger cross-section for inelastic scatteringthan any one had expected. At the sametime, the SLAC Group A-MITcollaboration was finding the same resultfor inelastic electron scattering, of coursewith much greater statistical precisionsince SLAC accelerates electrons. Thisresult was not surprising, since the muonand electron always seem to behave in thesame way. A detailed comparison of theelectron and muon results is being made:to date no startling discrepancies havebeen seen.

This experiment, in addition to beingthe first to study inelastic muonscattering, covers a four times biggerrange of "q2" that previous studies ofelastic scattering. q2 is a parameter whichmeasures the violence of the collisions:the bigger q

2, the more violent the

collision, and the "closer" one comes tothe nucleus.

As well as studying muon scatteringfrom protons, Group E has measured thescattering from complex muclei. Fromtheir data they can deduce that thescattering from neutrons is very similar tothat from protons, perhaps a little less.They are also studying a peculiar"shadowing" effect first observed by theUC Santa Barbara Group working withprotons at SLAC. Muon scattering,electron scattering and photon absorptionare all very closely related: the scatteringprocesses are explained in terms of theabsorption of "virtual" photons.

In addition to the inelastic datamentioned above, Group E has beeninvolved in other investigations of themuon. Being analyzed now incollaboration with a group from LRL,Berkeley, are 1.6 million photographstaken at SLAC of sea level cosmic raymuons. It is expected that a few hundredmuons with energies greater than onetrillion electron-volts will be observed.

Jack Goad RetiresContinued from Page 1

Here Jack will hunt, fish, repair antiqueclocks ( a hobby of 25 years) and dosome hand-tooled copper work - anotherhobby he has enjoyed for some time. Hehammers, anneals, cleans and polishescopper plate into attractive ornamentsand pieces of art such as bracelets,ashtrays, candle-holders and dishes. Jacksays he plans to have Mrs. Goad, who is alicensed real estate agent, "keep herselfout of mischief" by keeping her hand inas an agent. He says she is a consistentwinner at Black Jack. She can tell at aglance every card that is played orunplayed at the table. Jack, it seems, isno slouch at the game himself.

Jack Goad is a big man who standstall, who likes to smoke and take a drinkas well as gamble. He's retiring becausehe's sixty-five - but that's the onlyreason!EIDTORS NOTE: Jack is the first

SLAC'er whose initial retirement wasfrom SLAC. Other employees haveretired from the project, but they hadeither previous military, civil service orsimilar retirement before coming toSLAC.

Drawing outlining aparatus used in muon scattering experiment.