1 ^* S Inte *r^ * * 0 Events and HappeningsIn the SLAC Community

lInteractio P op II I IDecember 1997 Vol. 8, Np. 12

Out of Pure Light, Physicists Create Particles of Matter

[The following is a press release written byT. Rickey of the E-144 collaboration. Otherreleases have been published in the NewYork Times and the San Jose MercuryNews.]

A TEAM OF 20 PHYSICISTS from fourinstitutions has literally made somethingfrom nothing, creating particles ofmatter from ordinary light for the firsttime. The experiment was carried out at

T. AC hv sc'intists and studeints fromthe University of Rochester Princ n E-144 Group: front row (l-r) Glenn Horton-Smith, Theo

the University of Rochester, PrincetonUniversity, theUniversity of Tennessee, Kotseroglou, Wolfram Ragg, Steve Boege; back row (l-r) Kostya

and Stanford. The E-144 collaboration Shmakov, Dave Meyerhofer, Charlie Bamber, Bill Bugg, Uli

reported the work in the Sept. 1 issue of Haug, Achim Weidemann, Dieter Walz, Dave Burke, Jim Spencer,Physical Review Letters. Christian Bula, Kirk McDonald, Adrian Melissinos.

Physical oeview Letters.Converting matter into energy is almost

LUIIlllullVlLAtdC LUCLay. IN Utl. l- I lJ. 11.UIL 1 UIL VV iLv i--

known example, but in fact experiments z Zo

converting matter into energy predate nuclearpower, going back to 1932 when Carl Anderson SLC Breaks Recordsfirst discovered the positron, the anti-matter 1counterpart of the electron. When a positron and zan electron meet, they disappear in a flash of After a long, frustrating turn-on,energy. Now, sixty-five years after humans first the SLC started delivering recordlearned how to do that, they've finally succeeded luminosity in mid-October. The weekin doing the opposite: converting energy in the of October 26, the SLD logged 10,000form of light into electrons and positrons. Z's, as many as in the entire 1992 run.

Converting energy into matter isn't The next week, it was 14,000 Z's, nearlycompletely new to physicists. When they smash °o double the old record. The accelerator Ztogether particles like protons and anti-protons operators raced to outdo each otherfor

in high-energy accelerator experiments, the initial each new record shift or day. For the

particles are destroyed and release a fleeting burst first 10K week, the Director hadof energy. Sometimes this energy burst contains promised a party for the operators and

very short-lived packets of light known as "virtual o maintenance crews who made itphotons" which go on to form new particles. In possible. On November 5, theZothis experiment scientists observed for the first rainclouds held off long enough for

time the creation of particles from real photons, everyone to enjoy a well-deservedpackets of light that scientists can observe directly celebration.in the laboratory. No -- Nan Phinney

Physicists accomplished the feat by dumping z _ oo i-Jnt1 C 1 o _-_n_-_1_-Ar1_ n_ r_-11_ _ l~.o h

anll IlI'Ulm (amounIL t oI powero ILCdlIy dLP IILUc. L

(continued on Page 3, Column 1)1

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Local Students from La Entrada Have a Field Day

[Ed. Note: This letter to Dr. Richterwas received from a parentchaperone who participated in arecent school visit to SLAC.]

5 November, 1997

Dear Dr. RichterYesterday was my first

visit to SLAC as one of thechaperones for the technologyfield trip by the La Entradaeighth grade... I do not think Ihave ever packed so muchexcitement into a forty-eighthour period in all my life!

I have chaperoned animpressive number of field tripsand SLAC was THE BEST! Theextensive planning, preparation,and specially "8th grade"-geared presentationscoordinated by Dr.'s Decker,Erickson, Himel, andMarkiewicz and all of theparticipating SLAC staff werephenomenal. I truly believeevery student was enriched in away that will make adifference, in a very positiveway, in their future. Sciencecame alive for them and theyrealized that they shouldwonder about the "what if I dothis, what will happen" 's. Thistrip would be such a gift forfuture eighth grade classes if itbecame ongoing. I truly hope tobe able to be part of future eighthgrade field trips to SLAC...!Please extend my exuberantthanks and gratitude toeveryone that made yesterdaythe best!

Avogadro's number of thanks,

Lisa Cohen

The Interaction Point O 1997, is published by Stanford Linear Accelerator Center. Editor-in-chief, P.A. Moore; Production Editor, VickeeFlynn. Deadline for articles is the first of every month. Items are published on a space-available basis and are subject to edit. Submissionsmay be sent electronically to tip@slac.stanford.edu or by SLAC ID mail to TIP, MS 20. Phone 926-4208.

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Out of Pure Light(continued)

as it takes to run the entire nation but lasting onlyfor a tiny fraction of a second- into an area lessthan one billionth of a square centimeter, which isfar smaller than the period at the end of thissentence. They used high-energy electrons travelingnear the speed of light, produced by SLAC's two-mile-long accelerator, and photons from a powerful,"tabletop terawatt" glass laser developed atRochester's Laboratory for Laser Energetics. Thelaser unleashed a tiny but powerful sliver of lightlasting about one trillionth of a second (onepicosecond) -just half a millimeter long. Packedinto this sliver were more than two billion billionphotons.

The team synchronized the two beams andsent the electrons head-on into the photons.Occasionally an electron barreled into a photonwith immense energy, "like a speeding Mack truckcolliding with a ping pong ball," says physicistAdrian Melissinos of the University of Rochester.That knocked the photon backward with suchtremendous energy that it collided with several ofthe densely-packed photons behind it and combinedwith them, creating an electron and a positron. Ina series of experiments lasting several months theteam studied thousands of collisions, leading tothe production of more than 100 positrons.

The energy-to-matter conversion was madepossible by the incredibly strong electromagneticfields that the photon-photon collisions produced.Similar conditions are found only rarely in theuniverse. Neutron stars, for instance, haveincredibly strong magnetic fields, and somescientists believe that their surfaces are home tothe same kind of light-to-matter interactions theteam observed. This experiment marks the firsttime scientists have been able to create suchstrong fields using laser beams.

By conducting experiments like this, scientiststest the principles of quantum electrodynamics

Holiday Food/A Toy Drive

WE THE COMMITTEE FOR the SLAC Food/ToyDrive would like to make an appeal to the SLACcommunity to once again participate in our drive.In past years, SLAC participation has been"GREAT!"

We are asking for non-perishable foods,which will be taken to Second Harvest Food Bank.Toys will be collected by the American Red Crossfor distribution. Watch for flyers and barrels!

-Committee: M. Parish, P. Bradley, P. Pickett

I...... J II...- I -r-I........................

from the top left, then comes down the pipes on theright to collide with the electron beam in the stainlesssteel box. The scattered electrons are bent downwards,andpositrons are bent upwards in the string of magnets.Wolfram Ragg (r) adjusts the ECAL detector; TheoKotseroglou (I) is in background.

(QED) in fields so strong that the vacuum "boils"into pairs of electrons and positrons. The scientistssay the work could also have applications indesigning new particle accelerators.

Spokesmen for the experiment, funded by theDepartment of Energy, are Kirk McDonald,(Princeton) and Melissinos (Rochester). Also takingpart in the experiment were William Bugg, SteveBerridge, Konstantin Shmakov and AchimWeidemann at Tennessee; David Burke, Clive Field,Glenn Horton-Smith, James Spencer and DieterWalz of SLAG; Christian Bula and Eric PrebysfromPrinceton; and seven other physicists fromRochester, including David Meyerhofer, ThomasKoffas, David Reis, Stephen Boege, TheofilosKotseroglou, Charles Bamber, and Wolfram Ragg.

_~i~i~i~41HiILoThe following people joined SLAC through mid-November: Ignacio Aguilar, MD; Nima Arkani-Hamed, Theory; John Bartelt, BBR; John Back,BBR; Dmitry Bukin, EC; Sherwin Cabatic, ARD-A; Theresa Champion, BBR; Clarence Chang,ARD-A; Yue Chen, Theory; Brian Claxton, BBR;Michael Doser, EB; Edelmira Escoto, BDS; JoelGagarin, ES&H; Rupinder Kaur, ES&H; WalterKaye, Tech Info Services; Martin Kocian, EE;Witold Kozanecki, PEP-II; Alex Leung, SSRL;Bernd Lewandowski, BBR; Ziba Mahdavi, BSD;Roland Martin, BBR; Brendan Murphy, AD;Mikhail Petelin, Klystron; Corrine Purcell,Personnel; Filip Ronning, SSRL; Peter Sanders,BBR; Steve Shenker, Theory; Martin Shim,Klystron; Yun Song, Theory; Richard Talley,Klystron; Ann Torres, ARD-A; John Turek,ES&H; Paul White, SSRL; Bruno Zotter, ARD-A.

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SLAC Employees Win Documentary Award

SLAC EM-PLOYEE HANKGRAY, a homemovie hobbyist,scored bigrecently whenhe collected theprestigiousBlack AmericanC i n e m asociety's 15thannual studentand indepen-dent filmmakerfirst place awardfor hisdocumen-tary,"A Time to beRemembered: AJuneteenth

(l-r) Hank Gray and Al Btaker. Story."

Juneteenth is the oldest African Americancelebration in America. "A Time To BeRemembered" is a 59-minute docudrama thatchronicles the events that lead up to the fall ofslavery in this country. It is a well thought-outvideo presentation that is punctuated with superbperformances by local actors, live action shots,and contributions from local organizations. Thisbittersweet docudrama is a tale of North andSouth based on facts ignored by most historybooks. The production is sprinkled with liveaction that takes you on a journey back throughtime. It makes some uncanny comparisonsbetween today and yesterday that may shock andsurprise you.

Gray, a Senior S&E Technician in the PowerConversion Group, says it all started while hewas in his early teens when he got his first super8 film camera. Not long afterwards he begandirecting his younger brothers and sisters in little"no-budget horror films." He has also worked asa television director for seven years at TCICablevision in San Jose, where he directs his owntelevision program, "Science Faction," which canbe seen every Friday night on channel 15A at 7PM. Although Gray has been involved withdocumentaries on Silicon Graphics, NASA/Ames,and SLAC, this was his first attempt at writing,producing, and directing one. His goal is toproduce and direct documentaries on historicevents overlooked by the history books and thathave historical significance to African Americans.

Leigh Weimer of the San Jose Mercury News

wrote that the event put Gray in some pretty fastcompany. Also honored by the Society on thatsame night were Samuel L. Jackson, Yaphet Kotto,Pap Grier, Robert Townsend, and SmokeyRobinson.

"A Time To Be Remembered" included afew other SLACers. Executive producer Al Baker,a Technical Manager in the AcceleratorDepartment, who attended the ceremony at thebeautiful Watercourt of the California Plaza inLos Angeles along with Gray, was elated with theaward. "We started with an idea, went intoproduction, then into distribution, and won anaward on our first time out."

Anyone who has heard Jamie Davis, a SeniorS&E Technician in SLD, sing at one SLAC functionor another would not be surprised that his richbaritone voice contributed to the success of "ATime To Be Remembered." Davis said thatnarrating gave him the opportunity to acceleratehis ideas and skills, and to express his new-foundtalent. He looks forward to their next production,which will be about either World War I or theunderground railroad.

Steve Berry, a supervisor in the PowerConversion group who acted as special effectssupervisor, says it was a great project with whichto be associated.

"A Time To Be Remembered" was producedby Al, Jamie, and Hank (A.J.H.) Productions andis being distributed by Karol Media inPennsylvania. It should be available in mostlibraries, and is worth a look if you would like toknow more about the oldest African Americancelebration in the country. The video will beaired on January 14 in the SLAC auditorium.Notices will be posted in early January.

Faculty Milestone

EVA SILVERSTEIN WASRECENTLY appointedAssistant Professor at SLAC'sTheory Group. She receivedher Ph.D. in 1966 fromPrinceton University and hasworked at Rutgers University'cl a O C a *'a c y

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She is a leader in research on the stringtheory of elementary particle physics andassociated areas of particle and gravitationalphysics, an area to be further developed at SLAC.

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24th Annual SSRLUsers Conference

BLUE SKIES AND BALMY temperatureswelcomed the 135 attendees to the 24th AnnualSSRL Users Conference held October 16-17.Conference co-chairs David McKay (StanfordU.) and John Bargar (SSRL) assembled a dynamicprogram which spanned the multiple areas ofresearch conducted at SSRL. The conferenceopened with summary presentations by BurtonRichter and Keith Hodgson (Acting Director/SSRL). Pat Dehmer of the Department of Energyshared the results of the Basic Energy SciencesAdvisory Committee (BESAC) Report on thestatus of synchrotron radiation research andfacilities in the U.S.

SSRL staff members gave severalinformative talks on present and futuredevelopments at SSRL including new beam linedevelopments, the proposed SPEAR3 upgrade,and the Linac Coherent Light Sources. A newaddition to this year's program were threesummary level talks on synchrotron radiationdevelopments in several major fields of study.Jo Stohr of IBM addressed industrial applicationsof synchrotron radiation. Ed Westbrook ofArgonne National Laboratory discussedbiological applications of synchrotron radiationand Sam Traina of Ohio State U. focused on theopportunities and challenges for synchrotronresearch in molecular environmental science.

At the conclusion of the first day of theconference, attendees were invited outdoors toview nearly 40 poster displays by SSRLresearchers and graduate students. The SSRLUsers Organization awarded poster prizes totwo entries this year: Craig Bryant of LBNL for"Fluoresence-Detected X-Ray Magnetic CircularDichroism on Mn and Ni Doped MgO - MultipletSimulations and Sum Rule Analysis" and JenniferDubios (Stanford U.) for "Cu K-Edge XAS Studyof Highly Oxidized Copper Compounds."

The second day of the conference wasdedicated to more detailed and analyticalscientific presentations on research conductedat SSRL in four major areas: material science,

environmental science, protein crystallography,and biology. The seventeen invited speakerstraveled from a variety of educationalinstitutions including the University of Marne-la-Vallee in France, UCLA, MIT, U. of Idaho, U.of Colorado, Rutgers, U. of Washington and UC-Berkeley. U.S. research laboratories were alsowell-represented -Advanced Photon Source, LosAlamos National Labs, Scripps Research Labsand Lawrence Livermore National Labs.

A sometimes boisterous, sometimesbittersweet banquet was held at the Holiday Innin Palo Alto. Over 225 users and staff membersgathered to say goodbye to Arthur Bienenstockwho is heading to Washington, DC. As Master ofCeremonies, Ron Gould (SSRL) ushered in a hostof Artie's friends, colleagues and former graduatestudents who shared amusing anecdotes andmemories spanning Artie's 20 years as directorof SSRL. Artie will certainly be missed.

There were two well-attended workshopsheld on October 15 at SSRL prior to the UsersConference. Ingrid Pickering (SSRL) and RogerPrince (Exxon) chaired a workshop on"Applications of X-Ray Absorption Spectroscopyin Monitoring, Understanding and ImprovingPhytoremediation." The 25 attendees heard akeynote presentation by David Salt (Rutgers U.)titled "Phytoremediation: What is it, and Can itWork?" as well as seven additional presentationsby SSRL staff and invited speakers.

A workshop on MacromolecularCrystallography was hosted by Peter Kuhn andMike Soltis of the Biotech Group at SSRL. Theworkshop was a combination of practicals andtutorials. This training provided hands-onexperience on how to set up beamline hardware/software for very high resolution data collection,as well as how to prepare xenon derivatives atcryogenic temperature. Tutorials on highresolution data analysis and Patterson mapcalculations were provided and are now availableon the WWW.

-Suzanne Barrett

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Pilot Recycling Project

IN THE STATE OF SLAC Talk, SLAC DirectorBurton Richter announced Waste Minimizationgoals. One is to recycle 33 percent of non-hazardous waste-cardboard, paper, andbeverage containers.

Perhaps you have noticed new dumpstersaround the site labeled "Cardboard Only." Thesedumpsters have been added as part of a pilotrecycling project. This project involves tryingsome new measures to improve recycling ofcorrugated cardboard, office paper, and beveragecontainers. The project will provide guidance toSLAC on balancing improved recycling capabilitywith reduced subcontractor labor costs.

Aside from the "Cardboard Only"dumpsters, new collection containers for officepaper and beverage containers will be installed.These containers will be supplied by SLAC andwill replace the existing Kraft drums that aretypically supplied by the Stanford RecyclingCenter. Please note that during the pilot period,these drums will also remain at SLAC.

New collection containers will first beinstalled in the A&E Building and the CentralLaboratory (Building 40) as part of the pilotproject. Employees are encouraged to use thenew containers for collection of the followingrecyclable materials: white paper, mixed papers,newspaper, and beverage containers. Color-coded labels are attached to the containers foreach type of recyclable material. The labels alsoprovide information on the materials that areacceptable in each type of container.

IREMEMBER:I I

~I REDUCEI I

I REUSEI II RECYCLE IL6

Use the following guidelines in recyclingcardboard:

* Flatten the corrugated cardboard andleave it outside the nearest trash dumpster. TheFacilities Department will arrange to have thecardboard sent to the nearest "Cardboard Only"dumpster.

*If rainy, hold off to a sunnier day beforebringing cardboard outdoors. Wet cardboard isnot readily recyclable, and SLAC is obligated toprotect rainwater from contacting potentialcontaminants before it reaches the storm drainsystem.

*If you are near a "Cardboard Only"dumpster and wish to deposit a corrugatedcardboard box, empty the contents of the box(and recycle where appropriate) and flatten thebox before disposing it into the dumpster.

Use the following guidelines in recyclingoffice paper:

*Keep a small box in your office toseparately collect white and mixed papers (junkmail and colored papers) so that the number oftrips to the nearest collection containers can bereduced. The small box can also help preventpremature disposal of a piece of paper that youlater wished you had kept.

*Recycle white paper separately, wherepractical. White paper allows SLAC to recover abetter price than mixed papers. If you have whiteand mixed papers that will take much time tosort, then send the mixture to the mixed papercollection container.

*Arrange with the Facilities Department(x2207) if you are planning a major cleanup.Extra collection containers can be supplied on atemporary basis.

SLAC has a newly-formed WasteMinimization Citizen Committee. For questions,call Sandy Pierson (x2686) or Richard Cellamarex3401.

Richard Cellamare

Work Safe, Work SmartSLAC's record number of calendar daysbetween Workers' Compensation claims is77. This will be updated in the next issue,since data was not available at press time.

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In memoriam

Max Dresden 1918-1997"MAX WAS A TREASURE,"said Helen Quinn about MaxDresden during a memorialservice at SLAC on November15 to a gathering of over 100people. The memory of MaxDresden was honored byfamily, friends, students and

those who may have known him only slightly, butfelt that they wanted to be there.

Dresden died at age 79 on October 29 of cancer.He had been at SLAC for the past several yearsafter a long and illustrious career at Stony Brook inLong Island.

While it was a solemn occasion, it waspunctuated with humorous anecdotes about Max'slife and career. Solemnity came in the form ofMax's elder brother Sem Dresden, who felt"disoriented at the loss of a younger brother, whichgoes against the natural order." Humor came frommany of his students, such as Nan Phinney. Duringher Ph.D. defense, Max asked Nan if she was lookingforward to evidence of the existence of Z° particles."I just wanted to finish my degree, I didn't careabout the existence of those stupid particles!"

Donations can be made to the Max DresdenMemorial Fund, American Association of PhysicsTeachers, One Physics Ellipse, College Park, MD20740. -P.A. Moore

Lewis Sign 1931-1997LEWIS SIGN PASSED AWAYat the Menlo Park VA Hospicethree weeks ago. Lewsuccumbed to metastatic lungcancer.

Lew had struggled withalcohol and cigarettes most of

his adult life. He came to SLAC hating work "inthe valley." Actually, Lew disliked a lot of things;in spite of this, his personality fit well into theMFD family.

Lew was a teacher and a writer. He was amember of Mensa, and was a humanist of thehighest order. He loved language and paintedwith words in a way that was rare and beyondmainstream demands of his SLAC assignments.

He was a crusty old guy who told me manytimes that SLAC gave him the chance to salvagehis life. Lewis liked his work and most everyonehe worked with liked him! He can never bereplaced, and he will be forever missed.

-Carl Rago7

New Year's Day

Martin Luther KingDay

Presidents' Day

Memorial Day

Independence Day

Labor Day

Thanksgiving

Christmas

New Year's Day

January 1, 1998

January 19, 1998

February 16, 1998

May 25, 1998

July 3, 1998

September 7, 1998

November 26-27,1998

December 24-25,1998

January 1, 1999

Birthday Holiday*

*may be taken on employee's birthday orany other work day mutually agreed uponby the supervisor and the employee thatfalls within 365 days following theemployee's birthday.

Security UpdateAT A RECENT OPERATING Safety Committeemeeting, Rick Yeager presented an update onsecurity issues around the site.

*Two employees received a third traffic sanction.They had to park in the visitors' parking lot nextto the main gate and walk to their place of workfor two weeks. Sanctions are imposed by theDirector of Personnel.*The Traffic Control Program continues to gowell. It would help if new employees wereinformed of the program so they are aware of thetraffic rules enforced on site.* All SLAC employees must register their vehiclesand receive a sticker. 15% have not yet done so.*Reportly, some persons are exceeding the 25mph speed limit, with speeds of up to 40 mph.Over the past six months, speeders' average hasbeen 37 mph. Please slow down!*Losses due to theft this past year, FY97, were$67,000.

1998 Holiday Schedule

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Erik Sorensen: ElectricianTurned Woodcarver

WANT A ONE-OF-A-KIND gift? Look no further thanErik Sorensen, who has retired from SLAC and begun athriving new career in woodcarving.

Sorensen came to the United States from Denmarkin 1952. During his school years he liked drawing andafter school got a job with a woodworker for two years.But his formal apprenticeship was as an electrician andin that capacity he was hired when he came to SLAC. Hethen shifted to crane maintenance.

His hobby started with just picking up branchesand pieces of wood and gluing them together to makeshapes. Then he became more elaborate and started tocarve animals. "When I make something, each thingcreates a new idea for something else," said Sorensen.Nadine Wright (BSD) has several Sorensen woodsculptures.

He frequently visits a Danish lodge in San Raphaeland during a crafts exhibit there a man was taking lots ofphotos, one of which appeared in the local Marinnewspaper. That has now lead to a request from PleasantValley school for Sorensen to take his tools and techniquesto a second grade class where they are doing soap carving.

"I like working with cherry wood the best. It's ahard wood but it's good for detailed work withoutbreaking. It's also good on a lathe. I can spend 20minutes at the lumber store just looking at wood samplesto find just the right grain," remarked Sorensen.

Sorensen works out of his garage in San Jose andhe's got a system in which most of his equipment andwood is on rolling carts-so clean up is easy. Roll it upand close the door.

Some of Sorensen's carvings are on display at theNordic Shop on Santa Cruz Avenue in Menlo Park. Youcan also see model planes in the gift shop at the San JoseAirport. Those interested in ordering something specialcan call Sorensen at 408-268-4679. You might not be intime for Christmas, but there are always birthdays toremember.8