by Donald Sena, Office of Public AffairsBefore the present fixed-target run saw the

first proton circulate around the Tevatron,Fermilab management presented theAccelerator Division with a challenge: Push themachine’s intensity—or number of extractedprotons—to a new record, allowing fixed-targetresearchers to accumulate more voluminousdata at a faster rate than ever before.

The problem, however, is that higherintensity in the machine generally makes for anunstable proton beam, causing the beam towander from its designated path and eventuallyblow out of the beam pipe. This, in turn, shutsthe Tevatron down, bringing data collection inthe fixed–target area to a halt.

The perplexing question, simply stated, ishow does one raise the machine’s intensity,while keeping a stable beam for experimenta-tion? Dave McGinnis, head of the ProtonSource in the Accelerator Division, and histeam of engineers and technicians found theanswer in two types of beam–enhancementdevices: dampers and bunch spreaders.

Building upon other accelerator experts’past technological innovations and early ver-sions of dampers and spreaders, McGinnis’steam—engineer Jim Steimel and techniciansKen Koch and Gary Golinski—have spentmuch of the last few months developing,building and installing numerous dampers andtwo bunch spreaders in the Main Ring andTevatron. As of this writing, the Tevatron haspassed the old intensity record of 1.8 x 1013,recording a 2.28 x 1013 on Nov. 2, on the wayto the management-stated goal of 2.5 x 1013.

“The only way to get that intensity is tobuild the beam dampers,” said McGinnis, whohas had previous experience with these devices,

Volume 19 Friday, November 15, 1996 Number 22

f Building A Better Beam

continued on page 8

Dave McGinnis, head of the Proton Source, and his team of engineers and technicians developed the newest generation of dampers and bunch spreaders,which have pushed the machine’s intensity up and improved the beam’s quality.

A team in the Accelerator Division has raised the Tevatron’s intensity and improved thequality of the beam with technical innovations known as dampers and bunch spreaders.

INSIDE2 Painless Physics:

Magnets, Part 1

6 Birds of Fermilab

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Text by Hank Glass, Technical Support SectionEdited by Donald Sena, Office of Public Affairs

The experiment is ready and waiting. The researchers havecalibrated each calorimeter crystal and adjusted the high volt-ages on every wire in the tracking chambers. Every one of thehundred thousand readout channels of the detector is primedto record the swift passage of hadronic jets, electrons, muons,and other debris ejected from a violent subatomic collision. Allthat the experimenters are waiting for now is the arrival ofhigh-energy protons and antiprotons, streaming in from oppo-site directions to collide head-on in thecenter of the detector.

But how do the protons knowwhere to go? They don’t have aroad map. They can’t hop on a bus.They can’t stop a random pedestrianand ask, “Hey, mister, do you knowthe way to CDF?”

The protons need magnets toshow them the way.

The two main jobs of a particleaccelerator are to raise the energy ofthe particles and to steer them in theright direction. These jobs are per-formed by different devices: RF cav-ities use electric fields to acceleratethe particles, while magnets usemagnetic fields to steer the particles.This article will explore some of thedifferent kinds and uses of magnetsin accelerators.

Magnetic PersonalityHow are the magnets used at

Fermilab different from the magnetsyou use to stick your grocery list tothe fridge? Obviously they’rebigger—a Main Injector dipole is 20feet long and weighs 42,000 pounds,making them impractical for kitchen use. But they’re differentin another important way: unlike your kitchen magnets, inwhich the fields go around the outside of the magnet, anaccelerator magnet has its field on the inside. Accelerator mag-nets have a pipe going through the middle of them where theprotons travel; in Fermilab’s magnets, the field is directed intothat pipe to steer the particles, and very little field escapes out-side the magnet.

Magnetic fields act in ways unlike any other force innature. In a familiar force, such as gravity, all objects are accel-erated in the same direction. We don’t see some things fall up,some down, and others sideways. Magnetism is more compli-cated. First, it only acts on electrically charged particles; whenhumans, who are all electrically neutral, stand next to a

magnet, they don’t feel much (unless of course they’ve got asteel wrench in their pocket). Not only must the particle becharged, it must also be moving: a proton sitting in the middleof a strong magnet will just sit there and spin the time away,but another proton zipping in at high speed will get kicked bythe field. The force exerted by a magnetic field on a movingparticle not only depends on how fast it’s going, but in whichdirection: one particle, travelling at high speed in the directionof the field (that is, along a magnetic line of force) will experi-ence no force at all, but another particle, moving at the samespeed but at right angles to the field, will be deflected by it.

Magnet TypesA simple type of magnet is

called a dipole, and consists of twopoles. Magnetic lines of forceemerge from one pole (North) andre-enter the magnet at the otherpole (South). In the space betweenthe poles, where the beam piperesides, the field is nearly uniform.Magnet builders arrange thesedipoles around the circumference ofa circle, and have all their fieldspointing straight up, which is justwhat is needed to get a beam of pro-tons to circulate around the circle ina clockwise direction. Antiprotons,having negative charges, would cir-culate around these same magnetscounterclockwise.

The dipoles are all Fermilabwould need were it not for the factthat a beam of protons is a disor-derly bunch. They’re not all movingin exactly the same direction, but,instead, some want to drift sidewayswhile others want to move up ordown, away from the plane of the

ring. To keep them in line, we need another type of magnetcalled a quadrupole, which means a four-pole magnet (twoNorth and two South poles). The field in this type of magnetis zero at dead center, but grows linearly as you move furtheraway from the center. This means that a well-behaved protonmoving along the center, where it’s supposed to go, will beleft alone by the quadrupole. But an unruly proton, wanderingoff the beam axis, will be pushed back towards the center. Thefurther away it is, the harder it gets pushed. This results in afocusing of the beam of protons, similar to what a glass lensdoes to a beam of light. ■

Next issue: Part II of Magnets, including magnet fabrica-tion technology and superconducting vs. “normal” magnets.

made painlessH I G H E N E R G Y P H Y S I C S

Magnets, Part I

Steel laminations at one end of a dipolemagnet for the Main Injector.

Photo by Fred Ullrich

by Leila Belkora, Office of Public Affairs

Brenna Flaugher, Associate Scientist withthe CDF collaboration, is always happy to putquantum chromodynamics in plain English. Inthe past year, she has talked about her field—the study of quarks and gluons, and how theyinteract to form more familiar particles like pro-tons—to congressional representatives inWashington DC, to university groups aroundthe country, and to dozens of reporters fromnewspapers and radio stations who have calledher office in the CDF trailers. Most of theexplanations she gave this year were about thediscovery that some quark data do not matchtheoretical models, which suggested to somephysicists that quarks might have sub-structure.Sometimes, though, she gives in to popular

demand and chats with people about moregeneral physics topics. “I give tours, like togroups of kids. Next week they’ve convincedme that I have to give one to a crowd of 5thgraders. I did one where they brought me in tothe Education Center as a ‘real physicist.’ Thatwas sort of fun. You never know what they’regoing to ask.”

Flaugher has been at Fermilab since 1986,when she was a graduate student enrolled atRutgers University. Her contribution to thehardware side of the CDF experiment was todesign part of the electronic trigger system.The trigger helps experimenters separate themost interesting, highest-energy collisions fromthose that don’t provide any new insights.When it came time to analyze data, she had achoice of avenues: bottom quark physics, forexample, or studies of the electroweak force

She’s our

‘alignment czar,’”

says designated

Research

Division Head

John Cooper.

BrennaFlaugher

Associate ScientistResearch Division

Employee I.D. #8987

P r o f i l e sP A R T I C L E P H Y S I C S

between quarks and leptons. She specialized inquantum chromodynamics, or QCD. “The partI work on is jet physics. Jets are produced whenquarks collide,” said Flaugher. On computerscreens that show the tracks of particles in acollision, jets look like a narrow bundle of lines.

When she’s analyzing data, Flaugher hasalways concentrated on jet physics. Lately shehas taken on hardware challenges, too. “She’sour ‘alignment czar,’” says designated ResearchDivision Head John Cooper. “She’s in chargeof knowing where the detector is in space, rela-tive to the Tevatron. The detector deforms dueto its weight, and we need to know where itended up at.”

Flaugher’s job is to make sure the parts ofa new Silicon Vertex Detector line up. The newSVX is part of the effort to upgrade the experi-ment to take advantage of higher proton-antiproton collision rates that the Main Injectorwill provide in 1999. “The SVX is made out oflong ‘ladders,’ and two end-pieces which arecalled bulkheads, and the ladders have to getinstalled in the bulkheads and aligned to verytight precision. I’m working with the engineersto do that,” said Flaugher. “The ladder is thedetector, made of silicon wafers. The wafershave a whole lot of little strips on them, likewires, but they’re silicon. When particles gothrough, they leave a signal in one of thoselittle strips. And it’s very high precision, so thatwe can find very small displacements.”

Cooper notes that Flaugher has worked ona number of facets of the experiment, asidefrom jet physics and leading a QCD analysisgroup within the CDF collaboration. She wasOperations Manager during the colliding beamexperiment known as Run I, coordinating thedata-taking on a day-to-day basis with experi-menters and members of the AcceleratorDivision. “She has done an outstanding job ofmoving from one thing to another—thetrigger, alignment, daily operations, and theupgrade—and has had an impact on every-thing,” said Cooper.

Although she has worked on a wide varietyof projects, Flaugher sees communicatingresults from Fermilab to the global high-energyphysics community as her most important job.Like other members of the CDF collaboration,she helps shepherd new results through the var-ious stages from data analysis to publication injournal articles. Says Flaugher, “I see the papersas the output, the product of the lab. It’s whywe’re here: to put our results out into thepublic domain. I spend a significant amount oftime either helping students get their papersout and graduate, or taking over when they goon to other things. I think it’s really importantto get the papers out.” ■

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Ruth Pordes, head of the Online SystemsDepartment, meets monthly to discuss andevaluate products proposed for inclusion in theproject. FermiTools Librarian DonatellaTorretta, a guest scientist, handles the programinfrastructure and the coordination betweenthe product users and supporters.

Products and UsersFrom the initial offering of five software

packages, FermiTools has added 13 more prod-ucts over the past year and a-half. About 1,000people access the software files each month.The Internet domains that tap into Fermilab’ssoftware include commercial companies, educa-tion facilities and non-profit organizations.FermiTools customers include otherDepartment of Energy institutions, theNational Aeronautical and SpaceAdministration, Northwest Airlines, Bell Labsand McDonnell Space and Defense Systems.

Some of the products include: ■ juke: This product controls tape jukeboxesfor data analysis, backups and other applicationsthat require tape mounts that are inconvenientfor human operators to perform.■ NEdit: Several hundred scientific institu-tions, universities and laboratories are currentlyusing the most popular product, NEdit—aplain text editor for X/Motif systems.

ReactionPositive reactions from commercial and

educational users have come across theInternet.

“I just pulled down NEdit and I am veryimpressed. Our users have been wanting amotif-based editor for some time now andemacs (xemacs) was quite intimidating to someof them,” said C. Luther of Inet Inc. in Texasin an electronic mail message to Fermilab.

Similar reactions have come from otherareas. “Here at NASA Lewis Research Center, aproject is nearing completion...I have beenlooking for plain-line plotting widgets andfound the XYPlot widget in Histo-Scope to bequite nice,” said J.W. Mitchell of NASA LeRCin an electronic mail message from late 1995.

“Using the juke system was a real benefitto SLAC, and I appreciate your making thesoftware available,” said B. Weeks of theStanford Linear Accelerator Center in anothere-mail.

FermiTools has made a good start,according to Pordes. As the program’s visibilityhas increased at the Laboratory, Fermilab stafffrom other divisions have proposed their prod-ucts for inclusion, as the Computing Divisioncontinues looking for quality software productsthat might benefit groups outside theLaboratory. ■

FermiTools:Software Packaging 18 Months Later

Ruth Pordes (left), of theComputing Division’s Online Systems Department,and guest scientist Donatella Torretta work on the FermiTools project.

by Ruth Pordes of the Computing Division’sOnline Systems Department, guest scientistDonatella Torretta and Donald Sena of the Office of Public Affairs.

Fermilab’s Computing Division must con-stantly create innovative means to keep up withthe array of experiments, voluminous data andother computing challenges posed by scientificresearch at the Laboratory. As a result, thecomputing team and other staff at Fermilaboften develop software that is potentially trans-ferable to government entities, commercialindustries and scientific communities outsideFermilab.

To provide outside organizations theopportunity to take advantage of these innova-tions, the Computing Division launched theFermilab Software Tools Program (FermiTools)about 18 months ago. Through this program,Fermilab provides the broad Internet commu-nity with software packages developed at theLaboratory that have applications relevant toother domains. Fermilab offers these packageswith the goal of entering into collaborationswith interested and committed users for thejoint development, deployment and support ofmore software.

The FermiTools products reflect thediverse computing activities performed at theLaboratory, from the desktop to the centralcomputing services to the experiment halls.

The software productproviders have alreadyincorporated valuable con-tributions from outsideusers into some of theproducts and redistributedthem on the Internet.FermiTools developershave found that user-pro-duced innovations toexisting Laboratory soft-ware make a worthwhiletrade-off for the addedproduct support requiredfrom Fermilab.

“Feedback from theusers has helped the Fermilab... developers toimprove their products,” says Paul Lebrun,leader of the Physics Analysis Tools group inthe Computing Division.

The FermiTools working group, led by

What are the FermiTools Products?Currently there are 18 software packages. They include:

. CAMAC: UNIX CAMAC Software

2.CPS: Cooperative Processing Software

3.DCS: Drawing Control System

4.FISION: VME (and other related busses) Access Software

5.FRC: FASTBUS Readout Controller Software

6.FSCC: FASTBUS Smart Crate Controller Software

7.Histo-Scope / NPlot: Interactive Histogramming and Plotting Tools

8.juke: Robotic Tape Jukebox Control Software

9.murmur-kit: Distributed Error Reporting System

0.MXYZPTLK: C++ Library for Automatic Differentiation and Differential Algebra

1.NEdit: Mac-like plain text editor (X/Motif)

2.OCS: Operator Communications Software

3.plot-widgets: Motif widgets for graphing and plotting

4.Astronomical Data Analysis Framework

5.SPUDS: Single Platform Uniting Diagnostic Software

6.Transport: Charged Particle Beam Transport Software

7.UCM: Unix Code Management Software

8.UPS: Unix Product Support

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19

31

26 30

29

33 25

2021

41

2239

40

* Districts that include Chicago 1-18, 23,24,27,28

$231,701$443,343

$750

$26,124$8,673

$15,174

$9,709

$8,627

$1,064,385

$3,916,408

$70,105 $20,987

$294,205

$2,713,961 $864,575

$1,142,145

$1,167,538$2,034,650

$24,888,680

$652,664

$4,745,145

$46,424,852*

$156,401

$1,423,665

$97,468

$648,765$110,510 $117,791

59

58

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57

49

48

50

5245

44

433836

3735

34 32

42

46

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5153

Fermilab Buys Goods and Services in IllinoisFermilab purchases by Legislative District in fiscal year 1995

In Fiscal Year 1995, theDepartment of Energy’s Fermi National AcceleratorLaboratory paid $93.3 millionfor goods and services procured from vendors in the state of Illinois. The mapshows the distribution of FY95payments by legislative district.(The figures do not include$125 million in salaries paid to Fermilab employees, ofwhom 98 percent are Illinoisresidents.)

we see two populations of Canada goose atFermilab and around the Midwest. “There areresident geese, and a migratory population thatmoves through and doesn’t stay here over thewinter,” he said. The resident race is predomi-nantly the so-called giant Canada goose, orBranta canadensis maxima. The migratory birdsare smaller, and do not breed with the giants.The twice-yearly overlap of the races is nothingnew; flocks of the giant geese were year-roundresidents in the last century when settlersmoved into Illinois, said Kasper, but their num-bers dwindled and have only grown again inthe last few decades.

The giants do not hang around becausethey have “lost the instinct” to migrate, saysChris Whelan, a bird ecologist at the MortonArboretum in Lisle. “The geese do not have agenetic disposition to migrate; they learn thetiming and routes from their parents. It’s justlike in the recent movie ‘Fly Away Home,’” hesaid. The recent Columbia Pictures film isbased on a successful 1993 experiment to“teach” a safe migratory route to threatenedCanada goose populations in Ontario.

Whelan said he has the impression that thepopulation of non-migratory Canada geese inthe Midwest exploded in the late 1980s. ScottCraven, a wildlife biologist at the University of

How do theysurvive the coldweather?

An article by theaptly-named Dr. DavidBird in the 1996 issue ofBird Watcher’s Digestlists several adaptationsthat ensure the survivalof Canada geese duringextreme cold tempera-tures. The birds avoidfrost-bitten legs andfeet by getting alongwith a mere trickle ofblood supplying theirextremities.Furthermore a “netlikeweb” of veins andarteries ensures thatarterial blood flowingto the feet warms thevenous blood on thereturn trip to the heart.

Bird claims that thegeese can lower theirbody temperature by afew degrees to con-serve energy when theground is frozen andfood is unavailable.Also, the birds appar-ently tense their breast muscles and shiverimperceptibly to generate body heat.

by Leila Belkora, Office of Public AffairsIt’s a winter sight at Fermilab that stops

visitors in their tracks: five hundred or moreCanada geese roosting shoulder-to-shoulder onthe frozen surface of Swan Lake, heads tuckedunder their scapular feathers as protectionagainst an icy wind. During extremely coldspells they may sleep like this for days, simply“sitting out” periods when snow covers thegrass they depend on for food.

Even during milder weather, it appears thatthe 6,800-acre Fermilab site is like a Red Crossshelter for geese and other birds—a havenwhere there is more unfrozen water and greengrass than in surrounding areas, thanks to thewarmer temperature of the cooling ponds,whose function is to carry heat away fromWilson Hall, accelerator magnets or from thegases that cool superconducting magnets.

Visitors often remark on the large Canadagoose population, and ask Fermilab biologistsand birders if the situation has changed inrecent years. “I get lots of questions about thebirds at Fermilab, including the Canada geese,”says physicist and bird watcher Peter Kasper.Kasper maintains a popular Web page about thebirds of Fermilab (see sidebar). An e-mail fromClarence Hickey, a NEPA compliance officer atDOE who visited the Fermilab prairie and wet-lands, posed a typical question:

“In your birds data[on the Web page] youdiscuss the Canada gooseas a year-round resident.This is happeningthroughout the northeastand the midwest. OakRidge National Lab alsohas documented thisthere. And the geese arepermanent residents herein Germantown, withnests around the onsitepond. I’m wonderingwhy these birds no longerseem to have the instinctto migrate and whetherthere is some permanentchange here within thespecies or its races. It isworrisome that thismigratory animal ischanging its life style. I wonder if you have anyinsight into this?”

In fact, says Kasper,

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Wisconsin in Madison, confirmed that in theregion as a whole, the resident giant Canadagoose population has grown tremendouslysince the 1950s. One reason is restoration pro-grams, and the welcoming habitat that suburbsprovide. “As recently as 1965, the race wasthought to be extinct. But the bottom line is,big industrial sites, parks, golf courses, etc...bingo! Fantastic goose habitat. Goose heaven,we’ve created. There are no natural predatorsleft around, and the Canada goose is a prolific,very flexible bird.”

Supplemental feeding has also encouragedthe geese. Geese normally eat grass, corn seed,and a bit of pond algae, according to Kasper.At Fermilab, they particularly like the buffalopasture, and fallow corn fields. The ponds areimportant mostly for roosting.

Kasper believes that the resident goosepopulation at Fermilab has been growing, butnot as dramatically as many people think.“What you’re really seeing is the weather;roosting places are concentrated when theweather is rough,” he said. Kasper and otherbird watchers participate in the AudubonSociety’s annual “Christmas Bird Count” at theLab. Based on these counts, he said, “We havenot been seeing a linear increase in the num-bers; the highest count was in the late 1980s,when we had over 100,000 geese, but a coupleof years ago, the numbers were way down.”

The large resident population and massiveinflux of geese in winter pose some obviousproblems for Fermilab. To walk along the roadleading north from Wilson Hall, between SwanLake and the cooling ponds, is to run agauntlet of “goose-poop.” Bird diseases are apotential problem too, notes Craven. When

large numbers of birds converge, there is adanger of duck plague, for example, a virusaffecting ducks, geese, and swans, or aviancholera, a bacterial disease that NationalBiological Service scientists say is spreadingthroughout the U.S.

Kasper says a mitigating factor at Fermilabis that the ponds are well aerated. “You can getthe spread of diseases,” he acknowledges, “usu-ally in anaerobic water. The fountains [in thecooling water ponds] alleviate that problem.”

Kasper dismisses the notion that theCanada geese are a nuisance at the Lab, butsays it would be relatively easy to keep themaway from the heavily traveled areas. “My owntake is, it’s not a problem,” he said, gazing outhis office window over the ponds and woodsnorth of Wilson Hall. Because they nest on theground the geese are sensitive to predators likefoxes and weasels, and tend to avoid nesting inareas that have ground cover. “The geese don’tlike shrubs. We could control them by havingshrubby areas around the lakes, so their nestingsuccess would be low.”

Ultimately, Fermilab’s Ecological LandManagement Committee will have the responsi-bility to solve any goose problems that emerge.The Committee consists of representatives fromthe Lab and Argonne, the US Fish and WildlifeService, Morton Arboretum, the DuPageCounty forest preserve, and DOE. Bob Lootensof Fermilab’s Roads and Grounds department,who chairs the committee, says the group’smain effort to control the geese near the roadsand parking lots has been to discourage peoplefrom feeding the geese there. “Swan Lake usedto be a popular place to feed the geese—peopleused to bring their kids,” he said. ■

ermilab’s Geese

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Physicist and bird watcher Peter Kasper scans Lake La

Birding at Fermilab“The birding here is as good as at any

single site,” says DZero physicist and avid birdwatcher Paul Quintas, who was introduced tobirding at the age of 14 by a family friend.“The Lab is great because there is such avariety of habitats.”

Quintas and bird watchers in the Fermilabarea rely on a Web page that Peter Kaspermaintains to help them figure out what theyshould keep an eye out for at a given time ofyear, and also to establish whether anunusual bird is a first-time sighting for theLab. The site (http://www.fnal.gov/ecology/wildlife/list.html) lists 260 species,along with a chart showing what time of year to expect them.

Bird watchers’ landmarks at Fermilab are notthe high-rise or the sculptures, but rather “thefamous sparrow hedge near Lake Law” or “thepond near DZero where Tom Diehl saw theWhite Pelican, while he was driving back fromlunch.” When someone notices an uncommonbird, he or she usually calls or e-mails Kasper,and he passes on the news. Bird watchers alsomake use of the DuPage rare bird hotline at(630) 406-8111 to place or listen to messages.

Birders often visit the Lab from surrounding communities. The only constraint on theiractivities is that they should be accompaniedby a Fermilab employee if they venture intorestricted areas, such as the Main Ring road or ponds.

Great Egret (above), and Red-Tailed Hawk (below),on the Fermilab site.

having installed them in the Booster after theLinac upgrade. McGinnis said he askedAccelerator Division management for thechance to develop similar dampers for the MainRing and Tevatron for the fixed–target run.

Many people around the Laboratory, fromoperators to experimenters, said they are gladthat McGinnis and his team were given thechance. Accelerator operators attribute themachine’s record–breaking performance to the

dampers, whilefixed–target researcherspraise their enhanceddata collection on thebunch spreaders.

“The intensity recordwe have achieved hasbeen the result of [thedampers team] work,”said Bob Mau, head ofaccelerator operations.“We could only reachabout 1.2 or 1.3 x 1013

without the dampers,but with them, we areable to go up.”

DamperTechnology

The damper processis a system that deter-mines where the beamis in the beam pipe, andcorrects the path of theprotons if they are offcourse.

A damper “is basi-cally a feedback system that measures where thebeam is, asks if it’s in the right spot and, if it’snot, puts it there,” said McGinnis. “It’s justfeedback.”

The beam of protons in the pipe is a cur-rent source. When the beam travels throughthe pipe, it leaves an electromagnetic wakebehind it. When the beam travels across animpedance, such as a device that sits in thebeam pipe, it leaves a voltage wake that “sitsthere and rings,” according to McGinnis. Thehigher the intensity, the larger the wake. When

the next particle bunch encounters the wake,the bunch could get a voltage kick, moving itout of position either horizontally, vertically orlongitudinally. This problem is especiallycommon in the Main Ring, as there are manydevices located in the beam pipe. [McGinnissaid developers of the Main Injector areworking hard to ensure the machine has min-imal impedance in the pipe, so operators can“stuff a lot of beam in there.”]

The first component of a damper is the“pickup,” a sensor that gauges the particlebunch’s exact position in the beam pipe. Thepickup sends the signal to an electronics systemthat determines if the beam is in the properspot. If the beam is on course, no adjustment ismade. If the beam has shifted from its desig-nated path, the electronics send a signal to a“kicker,” which adjusts the beam’s path to itsrightful place. The dampers, in essence, undothe effect of the voltage wake left in the beampipe.

“If the beam starts to become unstable—starts poking its head above [where it shouldbe]—then we immediately sense it and slap itshead back down,” said McGinnis.

That explains the process, but why thename? McGinnis said the name “damper” is amisnomer. When beam is injected into an accel-erator on the wrong orbit, the beam oscillatesaround the correct orbit. Dampers were firstused to remove the injected oscillations—accel-erator specialists referred to this process as the“oscillation being damped.” McGinnis said abetter name for his devices would be “beamstabilizers,” but once accelerator nomenclaturehas been established, it is hard to change.

McGinnis also said non–operators haveasked why beam enhancement devices likethese didn’t get much attention in the collidermode. The reason is that accelerators used forcollider physics do not have very high intensi-ties. For example, there are only six protonbunches in the Tevatron at any one time duringcollider operations. Fixed–target physics, on theother hand, has about 1,000 bunches in themachine at one time.

Furthermore, McGinnis is quick to point

Pickup Kicker

beam current

BetterBeamcontinued from page 1

DampersDampers gauge where the beam is positionedand corrects it if it has moved off course.

The Bunch SpreaderThe bunch of particles is“fattened” to fill more ofthe bucket, thus any wigglein the beam will have less ofan effect on the bunches.The spreader also reduces“super bucket” problems, orsome buckets having moreparticles than others.

Energy jitter or wiggle

Particle bunch

Bucket(dotted line)

Time jitter or wiggle

As the bunch spins, the spreader changesthe shape of the bucket a few times…

1. The Pickupgauges position of beam

2. Electronics determine if thebeam is on the correct path.

3. If the beam is off its path, the “Kicker” will

put it back on course.

The dampers/ bunchspreader team at thespreader’s control rack.From left to right: JimSteimel, Ken Koch, GaryGolinski and DaveMcGinnis.

out two important factors. First, he said hedoesn’t want people to blow the importance ofthe dampers out of proportion. He said thedampers are just one part of a big chain of soft-ware, hardware and hard work that makes themachine run. Secondly, McGinnis said he wantsto withhold his excitement for the innovationsuntil the Accelerator Division has reached theirgoal of 2.5 x 1013.

Bunch SpreaderWhile the operators have praised the

dampers, experimenters have noticed thebiggest impact from two newly installed bunchspreaders. McGinnis said he is surprised by theattention the spreaders have received aroundthe Laboratory, saying the dampers constitutedweeks of labor and the spreaders were installedin a day.

“The dampers laid the groundwork downso we can actually play around and put in littlecute things like bunch spreaders,” saidMcGinnis.

McGinnis said he found out about prob-lems with the quality of the beam indirectlyfrom experimenters. He heard that somebunches had more particles in their bucketsthan others (a bucket is the boundary that rep-resents how far out particles can spread beforebeing lost, such as water in a bucket). These“super buckets” or “super bunches” werecausing problems for the experiments.McGinnis also said a related problem has to dowith beam movement. The beam tends towiggle, and, if the beam is compact, a slightwiggle will be proportionally large, affectingextraction. By making the bunch “fatter,” thesame wiggle has less of an impact. The bunchspreader, in essence, blows the beam up in astable, controlled manner (see diagram below).

“I never even really knew that there was aproblem with the beam quality. It got to me byword of mouth that the experimentalists wereunhappy with the slow spill—that it was ratty,”said McGinnis. “According to all of ourdampers, we had the beam as tiny as it can bein the machine. We had it nice and scruncheddown and all in the right spot. So, we said, ‘ifthe experimenters don’t like the beam tiny, they

must want the beam chubby.”After the team built the first spreader a

few weeks ago and installed it in the Tevatron,they turned it on just before a weekend runand didn’t tell anyone to see if researcherswould notice a difference.

“From what I heard, [the experimenters]showed up Monday morning, saying theywere very pleased with the reduction in superbuckets and overall improvement of beamquality,” said McGinnis.

Queried by email,Peter Kasper, aresearcher with E831(FOCUS), said he iswithholding his finaljudgment of the innova-tions until more timehas passed, but thespreaders’ initial impacthas been positive.

“Our experimentwas greatly helped bythe addition of thebunch spreader, but, asthe machine intensityhas gone up, the spillstructure problems havereturned, but to a lesserdegree of severity,” saidKasper. “The addition ofthe bunch spreaderimmediately increasedour data taking rate byabout 20 percent and,more importantly,enabled us to starttaking data at higher beam intensities. It alsoresulted in an improvement in the quality ofthe events as well.”

As the intensity increased recently, thesuper bucket problem showed up again, butnot as bad. To combat the super buckets athigh intensities, the team commissioned a newspreader in the Main Ring, which hasimproved beam quality even further and haseliminated most of the remaining super bucketproblems. ■

Pho

to b

y R

eid

ar H

ahn

…the particles begin to “spread”… …until the particles are spread among the entire bucket.

E866 NuSea “E866 continues to take datasmoothly. For the past few weeks we have been quite satisfied with both the beam intensity we are getting, andalso the performance of our spectrometer. Soon we willbe changing our spectrometer setting in order to shiftour acceptance to a different mass range,” said EricHawker, a graduate student from Texas A&M University.

E815 NuTeV “E815 has now reached 5E17 protonsand is continuing to accumulate data. Our test beamanalysis is beginning to show interesting results for thetoroids that we were never capable of seeing before,” saidBob Bernstein.

E872 Donut “The prompt neutrino beam is completely installed and the performance of our newmagnets meets the design specifications. We are now inthe process of debugging our detectors and the beamline.We think we can be finished with this work byThanksgiving. Stay tuned,” said Byron Lundberg,cospokesman for E872.

E781 SELEX “SELEX is busy with the exciting jobof understanding our data. The software is working, andwe’re trying to nail down real data rates, efficiencies andsignals,” said Jim Russ.

E831 FOCUS Erik Gottschalk, a collaborator fromthe University of Illinois at Urbana–Champaign, said thatthe FOCUS collaboration is consolidating its softwareefforts to make the most of the available computingresources. For example, he mentioned the high-level soft-ware diagnostics that are used to continuously monitorthe E831 detector. “The goal is to use the charm datathat we record every hour to provide rapid feedback onthe state of the experiment,” said Gottschalk.

E871 HyperCP “E871 is starting up. We got beamon target and are in the process of understanding thebeam tune in more details. In parallel with beam tuning,we are plateauing and timing in trigger counters,” saidcollaborator Kam-Biu Luk.

Updates October 24— November 6

Award for Prairie ConsultantBob Betz, Fermilab prairie consultant, won the

George B. Fell award at the recently completedNatural Areas Conference held in St. Charles.

According to Natural Areas News, thenewsletter of the Natural Areas Association, “TheGeorge B. Fell award is presented by the NaturalAreas Association in recognition of outstandingand sustained individual accomplishments in theareas of natural areas identification, protectionand management.”

ACCELERATORThe Accelerator Division continued to push the

intensity of the machine higher over the last two weeks.The owl shift on Nov. 1 performed some fine tuning ofpositions in the Switchyard in an effort to decrease lossesdown the lines. The other effort involved increasing theintensity of the machine as the losses improved. EarlyFriday morning, the Accelerator Division reached a newrecord intensity of 2.27 x 1013.

The weekend of Nov. 1–4 saw a very reliable protonbeam with 63.25 hours of high–energy physics out of ascheduled 72 hours. On Saturday, Nov. 2 in the eveningshift, the Accelerator Division reached yet another inten-sity record, hitting 2.28 x 1013. Accelerator operationscontinued its smooth run with 21.75 hours ofhigh–energy physics out of 24 from 8 a.m Nov. 4 to 8a.m. Nov. 5. The only downtown in that stretch was dueto a Tevatron quench during the early morning hours ofNov. 5.

During the early part of the week, antiproton sourcepersonnel were performing deceleration studies.

FIXED-TARGETCollaborators provided this update on fixed-target experiments.

E835 Charmonium “Since the last report, wehave had one run at the chi-2 resonance, accumulatingabout 2 inverse picobarns of good data. We are nowwaiting for the antiproton source to complete its deceleration studies,” said Stephen Pordes.

E799 / E832 KTeV “Finally, we are taking physicsquality data on tape for E832 with lots of CP–violatedKaon to two pion decays. We hope to continue the current data taking mode until Christmas,”according toFermilab physicist Bob Hsiung.

E862 Antihydrogen The Pbar group has beenworking on deceleration ramps, so the experiment hasn’thad any beam time recently, according to Dave Christian,E862 spokesman.

L A B N O T EFERMILAB TALENT SHOWCalling all talented Fermifolks! Dust off yourdancing shoes and blow the cobwebs out of thatold trumpet—it’s time to strut your stuff at theFermilab Talent Show on Saturday, January 25 inRamsey Auditorium. Performers must include atleast one person who is a Fermilab employee, user,contractor or graduate student, and performanceswill be limited to 7 minutes. No audition necessary,but we will need a description of your performance.To find out more information, pick up a form fromKathy at the Wilson Hall Atrium Desk or e-mailJanet MacKay at MacKay@fnal.gov.

WednesdayLunch

November 20

Calzone Filled withRatatouille, Basil

and Three CheesesPoached Pear w/Bitter

Chocolate Sauce

Thursday Dinner

November 21

Shellfish Chowder w/Fresh Thyme

Grilled Duck Breastw/Orange Gran Marnier SauceBeet RisottoApple Strudel

w/Cranberry Sauce

Wednesday Lunch

November 27

Cheese FondueMediterranean Salad

Grapefruit Slices in Rum w/Candied Rind

Thursday Dinner

November 28

Closed

Lunch served from11:30 a.m. to 1 p.m.

$8/personDinner served at 7 p.m.

$20/person

For reservations call x4512Cakes for Special Occasions

Dietary RestrictionsContact Tita, x3524

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Dear Editor,We want to thank everyone who is

involved with FermiNews. I’m sure that manyof the readers glance at it and give it theheave-ho; to those people, I say you don’tknow what you have. You see, I’m not aphysicist, don’t work in “high” tech and Ican hardly tell you the difference between aproton and a neutron, and, unless you guyscome up with a Lucky Charm, I wouldn’tknow what to do with it. But please under-stand this: as a consumer, I see the resultsand the products that the “hands” ofFermilab have created. I would joyfullyremind you all to step back from time totime from the micro-cosmic and see themacro-cosmic effect you are having on ourworld (from refrigerators we plug in to ourcar lighters to curing cancers). Enjoy yourlook around.

I promise you that when you do, youwill again see what brought you to your indi-vidual fields in the first place. Rememberyour first lesson in physics class: for everyaction there an equal and opposite reaction;so lighten up on your co-workers. You maybe working with big machines, but you’restill little people, and we all benefit from yourwork faster when you get along. We can’twait to see how your next “find” will affectour lives. I would like to also let you knowthat FermiNews is passed along to the localhigh school, where I hear it is quite ateaching tool, especially the section on“Painless Physics.” (So don’t throw yoursaway; take it home, give it to your kid oryour neighbor’s kid.)

Lastly, you keep pushing for new scienceand we’ll keep pushing for new funding.

~ Pastor Jeff HauserElliott, Iowa

LETTER TO THE EDITOR

Pilot Program Wins AwardFrom Vice President Goreby Leila Belkora, Office of Public Affairs

In October 1996 Secretary of EnergyHazel O’Leary presented one of Vice PresidentAl Gore’s National Performance ReviewHammer Award Plaques to the BusinessManagement Oversight Process (BMOP) team.Associate Director Bruce Chrisman, a BMOPteam member, will be honored at a ceremonylater this month for individual team members.

The Hammer Award recognized efforts bygovernmental teams or agencies to make government work better and more cost effec-tively. The hammer in the award—an actual $6hardware store item—is a tongue-in-cheek reference to the Defense Department’s expen-diture (in about 1990) of $600 for an ordinaryhammer. The team award is a hammer in analuminum frame, while individual team members will receive lapel pin hammers.

The National Performance Review beganin March 1993 with the twin missions ofmaking government work better and cost less.Said Vice President Gore, who leads the effort,“The National Performance Review can reducethe deficit further, but it is not just about cut-ting spending. It is also about closing the trustdeficit: proving to the American people thattheir tax dollars will be treated with respect forthe hard work that earned them. We are takingaction to put America’s house in order.”

The motivation for the BusinessManagement Oversight Process pilot program,says Chrisman, was complaints from DOE labsthat the oversight audits were intrusive. Then-undersecretary Charles Curtiss put amoratorium on business reviews and set uppilot programs to make them more efficient.”Fermilab Director John Peoples askedChrisman to participate in the pilot team.

Chrisman said the team met for three daysin Washington, DC and came up with a pilot program. For example, DOE would only beallowed to come in for two weeks. The reviewshould be heavily based on the contractor’s orlab’s self-assessment. This would be the basisfor the review.

Argonne National Lab was the first to testthe pilot program. Fermilab had its first reviewunder the pilot scheme in January 1996.

“The program was declared a rousing success, and it was expanded to non-lab contractors” said Chrisman.

Chrisman says the new oversight process“saves effort and time rather than money,”although it also saves DOE overseers money in reduced travel costs. ■

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■ Housemate wanted for nice house in Warrenville,very nice area, 1/2 mile from Fermilab. Own bed-room, living room, bathroom, dining room, kitchenand study room share with one single, $300 plusutilities. Call Chen at x8381 or (630) 778-1107, oremail chendi@fsgi01.fnal.gov

FREE■ Free affectionate, older female cat. Spayed anddeclawed. Long hair, sable with black stripes. Betterfor a family without young children. Call (630) 365-6927.

Published by the Fermilab Office of Public AffairsMS 206 P.O. Box 500 Batavia, IL 60510630-840-3351ferminews@ fnal.gov

Fermilab is operated by Universities Research Association, Inc.under contract with the U.S. Department of Energy.

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The deadline for theFriday, December 13 issue of FermiNews is Tuesday, December 3.

Please send your articlesubmissions, classifiedadvertisements and ideasto the Public AffairsOffice, MS 206 or E-mail: ferminews@fnal.gov

FermiNews welcomes letters from readers. Please include yourname and daytimephone number.

C L A S S I F I E D SNOVEMBER 16William Windom performsTHURBER at Fermilab’sRamsey Auditorium onSaturday, November 16 at8 p.m. Tickets are $15 andavailable through our boxoffice at (630) 840-ARTS.Probably best know for hisEmmy Award-winning rolein the lead of NBC-TV’s1969-70 series, “My Worldand Welcome To It” basedon the writings of JamesThurber, William Windom will be bringing his one-man show back to Fermilab. Coming up:BEAUSOLEIL on January 18, 1997 for $17.

NOVEMBER 19Blood Pressure Screening from 11:30 a.m. to 1 p.m.in front of the Users Office.

NOVEMBER 22Fermilab International Film Society presents Romeo& Juliet. “A beautiful version of the Shakespeareclassic. Zeffirelli creates a stunning adaptation withmore action, humor and sexiness than has ever beenseen in the tale.” Directed by Franco Zeffirelli,U.K./Italy (1968) 152 minutes.

DECEMBER 6NALWO Potluck at the Village Barn, 6 p.m. Bring adish to serve 12, or $3 to cover costs. $1 additionalcost for adults consuming alcoholic beverages.

ONGOINGEnglish lessons, Thursdays in Users Center, callJeanette Antoniuk at 769-6518. German lessons,Tuesday evenings in 20 Nequa, call Angela Jostleinat 355-8279. NALWO coffee mornings, Thursdays10 a.m. in the User’s Center, call Mary Brandt at961-5194.

CALENDAR

M I L E S T O N E SAWARDOn October 24, the Chicago Charter ChapterAssociation of Energy Engineers presented an awardto Steve Krstulovich for Energy ProfessionalDevelopment.

BORNLuisa, on September 30, to Jurgen Engelfried(Physics Section) and Aurora Orozco.

B E N E F I T N O T EDEADLINE TO ENROLL IN FERMILAB’S FLEXIBLE BENEFITS PLANThe deadline to sign up for one or both of theHealth Care Reimbursement Account and theDependent Care Reimbursement Account is by theclose of business on November 27, 1996 in theFermilab Benefits Office. If you need forms or infor-mation, call the Benefits Office at x3395, 4362, or4361 or stop by 15WHSW.