FN EE RW MS I FERMILAB AU.S. DEPARTMENT OF ENERGY LABORATORY Shutdown marks end of era for 800 GeV fixed-target program 2 Fermilab Photo Volume 23 INSIDE: Friday, February 11, 2000 Number 3 6 Jane Monhart f 8 Safety Record Keeps Improving 10 Guide to Wilson Hall Construction 13 Talk of the Lab by Mike Perricone COVER: The early days of FermilabÕs fixed-target program produced one of the major discoveries in It was an era of great growth, sometimes instantaneous growth. particle physics in 1977Ñthe upsilon particle, or ÒOne of my fondest memories is of becoming an extraction expert,Ó said bottom quark. The experimenters shown are Chuck Brown (foreground), with Dan Kaplan, Hans Sens, Roger Dixon, whose Fermilab career began in the Switchyard, extracting Jeff Appel and Bob Kephart lined up behind him; and beam from the old Main Ring and sending it to the fixed-target experimental atop the detector apparatus, from left to right, Al Ito, areas, a quarter-century ago or thereabouts. Dave Hom, Ken Gray, Koji Ueno and Steve Herb. About two months into his Lab career, Dixon received a 3 a.m. call at home. There was a beam problem. He jumped into his car and sped to the Lab. ÒWhen I arrived,Ó he recalled, ÒI was greeted by a message on Channel 12 of the Laboratory television system that said something to the effect of ÔExpert Has Been Called.Õ I thought, ÔMe? Surely, they donÕt mean me.Õ Yet there it was, right on the screen, big as life. I was expected to be an extraction expert, and perform some magic.Ó Somehow, he did. The 800 GeV fixed-target program at Fermilab drew to a close on Friday, January 21, when the beam was turned off from the Main Control Room. The shutdown marked the end of an era with antecedents in the very earliest days of the Laboratory, an era producing not only great discoveries but magical memories, and mirthful ones, too. The shutdown marked the end of an era extending back before colliding beams, and before experiment collaborations numbering in the hundreds, an era when firing particle beams at fixed targets dominated the LabÕs experimental program, an era when the energy booster called the Doubler produced new Photo by Reidar Hahn phenomena in unexpected places. Steve Baginski was on duty in the Main Control Room when the 800 GeV fixed-target beam was shut down for the final time. 2 FERMINEWS February 11, 2000 SHUTDOWN of 800 GeV fixed-target program closes one era but opens another. ÒThe day we went from 400 GeV to 800 GeV,Ó people poured a lot of their energy into that recalled John Cooper, now head of the Particle program to make it work. In some ways, there may Physics Division, Òthe cafeteria served a ÔDoubler.Õ have been a closer feeling around the Lab. I did Two hamburger patties on one bun.Ó my thesis on an experiment with 36 collaborators, and that was regarded as a huge group.Ó A DIFFERENT CULTURE TodayÕs collider detector collaborations approach 500. The new phenomena included major breakthroughs in physics, including the discovery of the upsilon But Mike Shaevitz, a fixed-target experimenter particle, or bottom quark, in 1977. as early as 1975 and now the LabÕs Associate Director for Research, sees a change, not an ÒWe were a dozen guys on a mission out on the end: a transition to a new direction using the prairie, keeping our high-tech toys together with Main Injector beam at 120 GeV, allowing the duct tape and aluminum foil,Ó said Dan Kaplan, simultaneous operation of fixed target experiments who worked as a graduate student on the and Tevatron collider experiments. experiment led by Leon Lederman, alongside other emerging stalwarts including Fermilab ÒIt really isnÕt the end of the fixed target program physicists Jeff Appel, Chuck Brown and Bob at Fermilab,Ó Shaevitz said. ÒWeÕve gone through Kephart. 400 GeV, then 800 GeV. Now weÕre dropping back to 120 GeV but with very high intensity. It was a time when young physicists were beginning significant journeys. One such early ÒNeutrino interactions will continue to be a real journey produced pioneering work in hadronic focus of fixed target experiments,Ó he continued. production of charm particles; precision ÒThe energy is lower but the beam intensities measurement of charm lifetimes; some of the Fermilab Photos first uses of the silicon vertex detectors that have Above: Named FermilabÕs since become the mainstays of present-day collider fourth director in March 1999, Michael Witherell was the experiments; and led to the prestigious W.H.K. spokesman for experiment Panofsky Prize in particle physics in 1990 for E567 (ÒSearch for Charm Michael Witherell, who was named FermilabÕs Production in Hadron fourth director in March 1999. InteractionsÓ) in 1979. It was a different time with a different feel. Left: The 800 GeV line played ÒSo many of us lived in it, grew up in it, had a major role in Fermilab history. our formative experiences in that [fixed-target] program,Ó said Joel Butler. ÒWe saw the evolution of the field, from bubble chambers to very sophisticated high-speed electronics, silicon detectors, massive amounts of computer data. The early days were pretty crazy, and a lot of FERMINEWS February 11, 2000 3 ThereÕs no questioning the historical competitiveness: the fixed target program represented the energy frontier for the first half of FermilabÕs existence. The major directions of particle physics research trace their origins to the fixed-target program, and Shaevitz described the linkages. The earliest experiments, he said, focused on neutral current and neutrino interactions, a key to establishing the soundness of electroweak theory, unifying the electromagnetic and weak nuclear Photo by Reidar Hahn forces. Neutral current was proposed in the Now the LabÕs Associate Director for Research, Mike Shaevitz was the spokesman for the NuTeV experiment and a veteran of fixed-target experiments since 1975. electroweak theory work of Sheldon Glashow, Stephen Weinberg and Abdus Salam (they won the Nobel Prize in 1979), and Shaevitz said early will be far beyond what we used to have. With neutrino fixed-target experiments at Fermilab MiniBooNE here, and with MINOS sending a beam (then the National Accelerator Laboratory) clearly to Minnesota, this will be one of the major placesÑ demonstrated neutral current eventsÑas did an if not THE major placeÑfor investigating neutrino additional observation at CERN, the European oscillations at accelerators. We believe there will particle physics laboratory. be a strong kaon program at the Main Injector, Further precision measurements hinted that the top for CP violation studies. What makes fixed-target quark was heavy, heading experimenters down the experiments unique is that one can have a clever trail that led to evidence for the top quark in 1994, idea, and think about an experiment with a smaller and then the announcement of its discovery in group. ItÕs a complementary program to the 1995, during Collider Run I of the Tevatron, collider program.Ó completed in 1996. It was a $55-million upgrade of the Tevatron that pushed the energy frontier A HISTORY OF ACHIEVEMENT from 400 GeV to 800 GeV in 1984, a project managed by Ken Stanfield, then head of the The shift from the 800 GeV beam to the Main research division and now the LabÕs deputy Injector program stems from a combination of director. At 800 GeV, the fixed-target program science and economics. remained the LabÕs main experimental thrust ÒThere are a lot of other experiments out there we until about 1987. could probably do,Ó Cooper said, Òbut weÕre now in With Fermilab experiments establishing its an era when you canÕt simply do an experiment just credibility, the electroweak theory pointed to the because you thought of it. When you first start in Higgs mechanism as the source of mass for the a new energy range, just looking is interesting. W and Z bosons. They were discovered at CERN, But as programs age, just looking is no longer and finding the Higgs would be a major coup for interesting. Somebody has already done that, it Run II of the Tevatron. And measurements by takes a lot of money, and it may be deemed by the NuTeV (Neutrinos at the Tevatron), an 800 GeV scientific community in some general way that itÕs fixed target experiment for which Shaevitz was not as compelling as going off to work at [the Large spokesman, combine with W mass measurements Hadron Collider at CERN]. Experiments must be at CDF, DZero and CERN to point to a light Higgs competitive at Fermilab, and competitive in the particleÑpossibly within reach of the Tevatron world environment as well.Ó when Run II opens in 2001. 4 FERMINEWS February 11, 2000 So many of us LIVED in it, GREW UP in it, had our FORMATIVE EXPERIENCES in that [fixed-target] PROGRAM. ~Joel Butler. Discovering the upsilon particle, Shaevitz noted, the proposed KaMI (Kaons at the Main Injector) has led to a ÒB-physics frenzy, with B-factories experiment, to continue their investigations into everywhere looking for CP violation in the kaon decays and CP violation. If approved, KaMI B-system.Ó The study of CP violation, the and CKM (Charged Kaons at the Main Injector) behavioral difference between matter and would join the neutrino experiments as the core antimatter that might explain the very nature of the 120 GeV fixed target program. of the universe, took major steps just within the ÒWe feel as if weÕve fully exploited the KTeV last two years with results from KTeV (Kaons at apparatus, and weÕre at a point of diminishing the Tevatron).