OI M * _ * Events and Happenings

I-= nte a ctIn in the SLAC CommunityI1 I tI*AtI Ldt d t lI ttI IJune 1997 Vol. 8,No. 6

E-155: Closing in on Parton SpinNINE MONTHS BEFORE THE run was to start, 85 +/- 3 physicists in experiment E-155 wereconfronted with a daunting challenge. The collaboration consisting of SLAC and 15 universities in theUS and Europe faced the task of building a completely new spectrometer in End Station A on ashoestring, making extensive changes to the two existing spectrometers, and carrying out R&D on anew target material. The collective E-155 team spirit overcame "Murphy," and achieved all of these

goals while also collecting the data from a three-month proposal in only two months.E-155 scattered polarized electrons off polarized protons and deuterons to study how the spins

of the quarks and gluons combine to produce the well-known spin properties of protons and neutrons.The polarized electrons scatter primarily from quarks with spins in the opposite direction. By

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reversing the spin of the electronbeam and measuring thedifference in the number of timesthe electrons were scattered, E-155 measured the netcontribution of the quark spinsto the overall spin of the protonsand neutrons. Measurements ofthese differences have shownthat the quarks do not carry asmuch of the total spin of thenucleon as expected. If theproton and neutron spins do notcome wholly from the quarks,where does the nucleon spincome from? The gluons hold thekey. In addition to measuringthe spin carried by the quarks,the experiment also shed lighton the spin carried by the gluons.A third spectrometer was builtat a larger angle to the beam tocollect information on collisionsin which the electronstransferred a larger amount ofmomentum to the quarks. Thesecollisions probe more deeply intothe swarm of gluons and pairs ofquarks and antiquarks in theprotons and neutrons and almostdouble the experiment's abilityto see the indirect contribution,e 1 1-or rne gluons. Bird's-eye view of End Station A, showing L-155 target in middle oreground,

and 5.5 , 2.75 ° and 10.5° spectrometers in the background. The remains of the(continued on Page 4, Column 2) n n h. f h ri

vR GrrV snpctrrometer can hb seen to the right.u., ·i v A.c, ~,,, v , 3,~,[,, .CI. V ,[,, ........ o...1 ,L, ... 1

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SPEAR- 25 Years

ON APRIL 28TH THE SLAC Community honoredthree events, in particular the SPEAR MilestoneCelebration held on The Green. Not only was it the25th anniversary of colliding beams at SPEAR; itwas also the 40th anniversary of the originalproposal to build the linac. In line with this was the100 year anniversary of the discovery of the electron.

Speakers at the event were: Burton Richter,SLAC Director; Martin Perl, SLAC Faculty

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SLAC Director Burton Richter welcorstaff with some stories about the ear

SPEAR and its garden shed begir

nes SLAC hnalrman; Arthur ilenenstocK, :tK1L Uivisionly days of Associate Director; and Sebastian Doniach, SSRLinings. Faculty Chairman.

25 years ago, on April 28, 19/2, the StantordPositron Electron Asymmetric Ring first collided abeam of high energy electrons with a beam ofpositrons. The SPEAR facility began its career inhigh energy physics and found a reincarnation as anational user facility for synchrotron radiationresearch.

(Photos courtesy of P.A. Moore)

7111(vC IL VWC 11 L ICd/iIIIy, I CdlJ / --i L li rI I 1111

McDonald waved his umbrellato the music, to the delight of his audience.

(L to R) John Rees congratulates BurtonRichter, while Arthur Bienenstock,

Seb Doniach and Martin Perl move on.

There has to be cake to mark a birthday,so here's to SPEAR at 25!

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SLAC Archivist Jean Deken displays severalvariations on the SPEAR proposal.

B.A.S.E.Contributes to

McKean FamilyFund

THE BLACK ASSOCIATION OFSLAC Employees (B.A.S.E) wouldlike to thank those in the SLACcommunity who contributed over$1000 to the McKean family fund.The McKeans lost nine familymembers in early May, in the worstfire in East Palo Alto's history.Anyone wishing to contribute cansend a check to the McKean Familyc/o Wells Fargo Bank, 1071 ElCamino Real, Redwood City, CA94063. If you go to a local WellsFargo Bank, the account numberis McKean Family, #022441528.

--J. Hubbard

Chinese AcademyPresident Visits

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Pictured here (I to r) are President Zhou of the Chinese Academy otSciences, David Burke and Juwen Wang of the NLCTA, and Ma-dame Zhou during a recent visit by Chinese dignitaries.

Jazz Concert

As the song says, "Summertime and the livin' is easy..."and music

floated over the trees during a jazz concert by JamieDavis and Friends.

"Cool Blues" - The Stanford Jazz, featuring Lee Alexander-Bass, Wayne Banks-Drums, Joe Hienemann-Piano, JoanMinor- Vocals, Jamie Davis- Vocals, and RobertMayer-Guitar.

(Photos courtesy of P.A. Moore)Technicians and sound crew mixing and mingling.

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U.S. Department of EnergyFRAUD, WASTE, AND

ABUSE HOTLINE1-800-541-1625

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Faculty MilestonesPROFESSOR ROGER H.MILLER will becomeEmeritus Faculty as of June1, 1997 after 37 years atSLAC. Professor Millerreceived his B.A. fromPrinceton Univer-sity andhis Ph.D. from Stanford

University. He was appointed as a ResearchAssistant in the Microwave Laboratory atStanford University from 1959-1961. ProfessorMiller started at SLAC in 1960 as a SeniorResearch Associate, and in 1974 was promoted toAdjunct Professor. Since 1983 he has been aProfessor of SLAC and his main researchinterests have been wakefield suppression inaccelerator structure, injection; positron sources,rf sources for the Next Linear Collider (NLC),and NLC test accelerator.

Professor Miller will continue at SLAC on a50% basis to work on R&D for the Next LinearCollider.

PROFESSOR PERRY B.WILSON will becomeEmeritus Faculty as ofSeptember 1, 1997 at 50%appointment. ProfessorWilson received his B.S. andM.S. from Washington StateUniversity, and his Ph.D.

from Stanford University in 1958. From 1958-1959 he worked as Staff Physicist at LinfieldResearch Institute, McMinnville, Oregon. In 1959he returned to Stanford as a Research Associatein the High-Energy Physics Laboratory. In 1964he was promoted to Associate Director ofOperations of the High-Energy PhysicsLaboratory, and to Senior Research Associate in1966. He moved to SLAC in 1969 and waspromoted to Adjunct Professor of SLAC in 1974.He has been Professor at SLAC since 1983.

Professor Wilson's research interests havebeen in the theory and design of rf systems forelectron storage rings and microwave linearaccelerators, and on the development of highpower rf sources for next-generation linearcolliders. He will continue at SLAC on a 50%basis to work on R&D for high energy linearcolliders.

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E-155 (continued from Page 1)

"It's just work."

To achieve the desired goals, theexperimenters had to work harder, smarter, andsafer. Construction of the third spectrometerinvolved contributions from SLAG'sExperimental Facilities Department (EFD) andGroup A, American University, Caltech, OldDominion University, Smith College, Universityof Massachusetts, University of Virginia, and theCollege of William and Mary. Upgrades to theoverall system were handled primarily by EFDand resident collaborators from other institutions.These modifications included adding shieldingaround the various detectors, upgrading the dataacquisition system, and even rewriting the testingprocedures for the manufacturer of some of theelectronics! Guidance of the experiment andgetting the data onto the tape was handled bythese groups along with the University of Basel,CEBAF, Clermont-Ferrand, Kent State University,Saclay, Stanford University, University ofMichigan, and the University of Wisconsin. TheUniversity of Virginia, with technical supportfrom EFD, was responsible for finding a way touse lithium deuteride (LiD) as the deuteron targetmaterial. This target material has almost twice asmany deuterons as the deuterated ammonia usedpreviously, which decreases the running timecorrespondingly. Intensive studies were requiredto make the material work in the relatively"warm" environment of the target, one degreeabove absolute zero. This represents the firsttime that LiD has been used in a high intensityproduction experiment.

"But does it work?"

As the experiment began, the AcceleratorDepartment, building on a development startedfor the previous experiment, produced a pulsethat was at least three times longer than thecustomary 120 ns SLED pulse, thereby allowinghigher beam currents and hence higher dataacquisition rates. To achieve these stretchedpulses, the maintenance crews had to keep almostevery klystron in the system humming perfectly.The efforts of the maintenance and operationspeople resulted in remarkable overall beamperformance with hardware availability at 90%and mean time to repair at 1.2 hours. A tour deforce, indeed!

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A REMINDER...SLAC'S AREA CODE

WILL CHANGE ON AUGUST 1,1997FROM 415 TO 650 I.I

Jim Allan's Radioactive Bananas!

chain "...right before their eyes!"

SET FREE TO DISCOVER what their folks do here, over 105 eager kids flooded SLAC on April 24, for what one

described as, "The BEST ever!" Take Our Children To Work Day event.Enthusiasm reigned supreme, from the morning hands-on experimental science exhibits, to the many

excellent department Open Houses in the afternoon. Clad in commemorative T-shirts and canary-yellow

radiation worker suits, the young people had fun trampling the site, searching for knowledge and insight about

themselves, their parents, and the wonderful world of SCIENCE!Post-event evaluation forms will be sent out to survey the participants' and sponsors' reactions to this

year's organization and to solicit constructive recommendations for any future events. Special thanks to all the

volunteers who worked at making this year's event such a success. We can't do it without you!

Photographs will be available for viewing shortly. An announcement will be made concerning the

purchase of group and/or individual pictures. Check out the Website for more information on this event:

http:/ /www.slac.stanford.edu/grp/bsd/toctw-97.html.Here are a few candid shots of the next century's Nobel prize winners! --Jan Crehore

The SLAC Home Pagedraws rapt attention.

Exploring Teamwork & ComlDear Liza: What's in that bucket?

5daughter, Cynta.

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Jim:

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Min Liu RememberedFOOK FAH (MIN) LIU, apostdoctoral research associ-ate at SLAC during its firstyears of operation, died ofliver cancer on March 28. MinLiu was a member of thestreamer chamber group atCT A r 1 r '_ o O l ,-1. . 1 Cr .

oLA-,L fo- ium loo tnrougn 1Y/ u;he then became a professor at California StateUniversity, San Bernardino. During the first fewyears at San Bernardino, he continued his re-search with the streamer chamber group, spend-ing summers at SLAC.

Min was born in Calcutta in 1934, and gradu-ated from the University of Calcutta in 1957. Hegot his first Ph.D. at Purdue and then came toStanford in 1962 as a research associate at theHigh Energy Physics Laboratory, studying pionphoto-production using the polarized photonbeam. In 1966 he left to take an assistant profes-sorship at Case Institute, before returning toStanford in 1968. While at SLAC, Min took chargeof the scanning and measuring of film from thestreamer chamber, as well as participating indata analysis.

He started a program in Computer Scienceat San Bernardino when he found that universitylacked one. He persuaded the University to offera course in Fortran programming, which hetaught. In his later years at San Bernardino, hedevoted most of his effort to Computer Science.

A memorial scholarship in Dr. Liu's namehas been established at the University. Contribu-tions can be sent to:

Department of Computer ScienceCalifornia State University, San Bernardino5500 University ParkwaySan Bernardino, CA 92407-2397

--Robert Mozley

The following people joined SLAC throughmid-May: Ian Adam, Experimental Group B;Chiquita Askew, MFD; Tomeka Askew, MFD;Lovetta Dunn, ES&H; Zev Kvitky, AD; DineshLoomba, Experimental Group E; RichardMount, SCS; Christopher O'Grady, BaBar;Clemens Wermelskirchen, SSRL; JingchenZhou, CD.

E-155 (continued from Page 4)

The experiment also demonstrated that theLiD target material was about six times as resistantto radiation damage as deuterated ammonia. Thisallowed the experiment to run at the highercurrents without the need to replace the materialas often. In fact, it was found that the materialwas a significant improvement over previousmaterials and it is likely that future spinexperiments will build on the research done bythe E-155 target group.

When the run concluded at the end of April,the experiment had collected in two monthsalmost all of the data it had originally proposedto collect in three months. Without the 110%effort given by so many of the people involved,this would not have been possible. The E-155collaboration would like to thank everyone whohelped make the run a success!

"What's Next?"

Has the potential for world class physics inEnd Station A finally been exhausted? Of coursenot! A natural follow-on is the proposed E-156experiment, which would make a more directmeasurement of the contribution of the gluons tothe nucleon spin by measuring asymmetries inthe production of charm quarks. The combinationof high energy and high intensity of the SLACpolarized beam would make it possible to measurethe gluon spin more precisely than any other labin the world in a relatively short time. Alsowaiting in the wings is a proposal to make aprecision measurement of the electroweak mixingangle using Moeller scattering in a new kinematicregion. --Lee Sorrell

E-155 Target

The Interaction Point ( 1997, is published by Stanford Linear Accelerator Center. Editor-in-chief, P.A. Moore; Production Editor,Vickee Flynn. Deadline for articles is the first of every month. Items are published on a space-available basis and are subject to edit.Submissions may be sent electronically to tip@slac.stanford.edu or by SLAC ID mail to TIP, MS20. Phone 926-4208.6

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Soaring to New Heights...MIKE PALRANGGOT INTER-ESTED in minia-ture planes aboutfour years agowhen he helpedhis youngestdaughter, then inkindergarten,make paper air-planes. Once

aware of the challenge of keeping small planes aloft,Mike turned to a more sophisticated method ofmaking miniature planes, and then went on to entercompetitions.

To make a plane, Mike starts out with SaranWrap that is 35 micro-inches thick, about 1/lOth asthick as your normal wrap. This is carefully craftedinto the wings and tail, and is framed in balsa woodthat is 1/6th as heavy as the usual wood. Ultra thinbalsa wood also is used for the propellers. To giveyou an idea of how light the finished product is, anairplane with an 18 inch wing span, complete withrubber band for rudder control, weighs about agram - the same as a dollar bill. Mike says this is acheap hobby in which to participate. Consideringthat the balsa he uses for the propellers costs $900 anounce, you may wonder. But the wood is thinnerthan tissue paper, so a little goes a long way.

The next step in a hobby is sharing it with otherenthusiasts. To that end, record trials are held tobetter national records. Such a competition washeld at the Cow Palace on March 9th, with Mikeentering a plane with an 18" wingspan. Mikesmashed the previously held record of 22 minutes, 6seconds that day. His plane remained aloft for 25minutes, 44 seconds. The contest director verifiesthe class description of the entries.

Mike will now defend his time at the nationalcompetition, which is held each August in Moscow,Idaho.

Adopt a Colleague

WOULD YOU LIKE TO make a new friend? Adda little to your vacation fund?

The SLAC Housing Office is experiencingincreasing challenges in the face of the presenthousing crisis. We would like to assure ouresteemed visitors and colleagues that they aretruly welcome to SLAC and to California. But, weare coming up short. We are running out of placesto house our visitors. If you live close to SLAC andhave a spare room, you might consider renting toa SLAC visitor for a short time. This could be anopportunity to get to know some of our visitorsand add some extra cash to your household budget.

Give the Housing Office a call for furtherdetails.

Ute HayesToni CamposHeidi Berndt

413241334130

Meet the HazardousWaste Management

Group

SLAC HAS A STRONG commitment to preservingour environment and making sure that our researchactivities are in compliance with laws andregulations. To do that, one of SLAC's groups isconcerned with Hazardous Waste Management.They are primarily responsible for identifying andcharacterizing waste, and arranging for pick up,storing and packaging. Waste is sent to varioustreatment, storage and disposal areas, andregulations require that the waste is tracked fromthe point of generation to the disposal location.Members of the group include (1 to r) Ardie Jacobs,Joe Christy, Yolanda Pilastro, Karen Holtemann(seated), Ron Sanchez (seated) and Clair Stevens.Not pictured: Brian Lalor, Hillary Russak, MichaelScharfenstein, and James Smith.

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Work Safe, Work SmartSince the last workers' compensation claim of4/14/97 involving days away from work wasfiled, there have been four more claims involvingdays away from work. The incidents occurredon 4/24/97, two on 5/8/97, and 5/12/97. Thenumber of calendar days between claims was 20days, 10 days, and 4 days, respectively. Therecord number of calendar days between claimsremains at 67 days.

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Meet Sharon Jensen"T TV l7 Y-- /-N T T- ITn- T I-- A Y

'IHb Hl'EUKlE''ICALPHYSICS Group onthe third floor of theCentral Lab runssmoothly due to theexpert administrationof Sharon Jensen, theTheory Group admin-istrator. Sharon hasbeen at SLAC sinceJanuary 1966. Shestarted working in theTyping Pool and aftersix months moved to

the Theory Group -- and never left."I like the variety and the interesting people," she

said. Sharon has constant responsibility working withthe seminar, colloquia, and Guest Lecture Programs. Shehandles all of the paperwork associated with the theorygroup, including the summer visitor program and long-term visitor requests, assigning office space, and helpingvisitors with their needs.

"Working with TeX and the World Wide Web areareas that I particularly enjoy. Things constantly changeand improve," she added. E-mail is another improve-ment that makes the life good at SLAC. Sharon hasbecome very involved in bulletin board submittal andpreparation for conference papers. She has mastered theskills needed to edit and submit papers to the variousbulletin boards in addition to preparing them for theSLAC Web server and SLAC-PUBS. This includes: TeXfiles, slide preparation, postscript files, uuencoded andcompressed files and archived files.

Working with the large numbers of theorists fromall over is a pleasure, because Sharon can say "I knewthem before they were famous." Sharon has seen SLACpost docs go on to faculty and research positions at majorlaboratories and universities around the world. Mosttheorists pass through SLAC again and again, so she getsa chance to see old friends regularly.

You are Invited to aJuneteenth Celebration

ALL SLAC EMPLOYEES ARE welcome to attend SLAC'seighth annual Juneteenth celebration which will be heldJune 20, 1997, 3:30 to 6:00 pm in the cafeteria picnic area.The event includes entertainment, an art and displayshow, door prizes, and a guest speaker. The theme thisyear is: BASEBALL - "50 Years After Jackie Robinson."There will be a barbecue at a cost of $10 ($5 for children)featuring ribs, chicken, hot links as well as other goodies.Look for the flyers posted around SLAC to get moreinformation on this event, including purchasing ticketsfor the barbecue or ordering t-shirts.8