Saying Goodbye to the TevatronPosted: March 8, 2012
Welcome to what I hope will be an occasional series: Labs of the Past, in which I take a look at labs or pieces thereof that no longer exist. Last fall, Fermilab shut down its flagship accelerator, the Tevatron, which had spent decades reigning as the most powerful particle accelerator in the world. Fermilab is still going strong and is throwing its considerable weight behind an innovative intensity frontier program, but I wasn’t the only one who was sad to see the Tevatron go. Needless to say, I was delighted to hear this week that data from the CDF and DZero collaborations is still actively contributing to the hunt for the Higgs boson. And in case you need to brush up on the accelerator’s many other achievements, the latest print issue of Symmetry Magazine includes a lovely piece on the Tevatron’s legacy by Rhianna Wisniewski.
I got my start writing about physics as a Fermilab intern, so when it was time for the Tevatron to be laid to rest last fall, I felt like I had to be there to say goodbye. What follows is my account of attending the Tevatron’s funeral on Septemeber 30, 2011.
Approximately seven hours after the Tevatron shutdown, I squeezed out of Fermilab’s Users’ Center bar to head to an Irish wake for what was, until just a few months ago, the most powerful particle accelerator in the world. This being the CDF party, The Drug Sniffing Dogs, the collaboration’s official rock band, had been going strong for three and half hours and showed no sign of stopping. The set list had devolved from what the lead singer called “crying in your beer songs” like “It’s the End of the World as We Know It (And I Feel Fine)” to dance party favorites like “Super Freak.” I had signed two commemorative T-shirts, one on someone’s body, while sipping Two Brothers’ Atom Smasher beer and munching on homemade cookies frosted with the CDF logo. The whole affair was tinged with the melancholy elation of the night after high school graduation, with everyone desperately savoring the last moments of an already bygone era before truly letting themselves move on to what they hoped would be bigger and better things.
For many physicists, those bigger and better things await them at CERN’s Large Hadron Collider, which is already colliding particles at over three times the energy of the Tevatron and only operating at half power. Others will be staying at Fermilab to work on the lab’s new intensity frontier program, which involves building state-of-the-art superconducting accelerators to study muons and those potentially faster-than-light neutrinos you’ve heard so much about. Still others are moving on to careers in industry or medicine, while some are retiring along with the Tevatron. But on Friday, all eyes were on the machine that had, for the last 28 years, led the way in the study of the fundamental building blocks of our universe and made the Illinois prairie the best place in the world to be a high energy physicist.
Shutting down the Tevatron was a multi-step process, all of which I watched from the control room of DZero, Fermilab’s other main detector and CDF’s complement and competitor. CDF stopped taking data first, while its emcee tried not to get too choked up and the DZero operators enjoyed the fact that they had outlasted their rival for a few precious minutes. But soon enough it was DZero’s turn to save its last pieces of data and power down. Then the action switched over to the accelerator’s Main Control Room, where Helen Edwards, who was the lead scientist for the construction of the Tevatron three decades ago, pressed a large red button that killed the beam by steering it into a metal target, followed by an equally large blue button that powered down the magnets. Cheers wafted into the DZero control room from the experiment’s assembly hall, where many members of the collaboration were gathered to watch the proceedings. And then it was over.
As the detectors stopped taking data and the Tevatron terminated its store for the last time, I wasn’t the only one with tears in my eyes. Many of the scientists I spoke with compared shutting down the Tevatron to losing a family member. At the lab-wide party at Fermilab’s high rise, Wilson Hall, after the shutdown procedure, the accelerator physicists and operators wandered the atrium with a shell-shocked look behind their eyes. The CDF and DZero scientists, after all, still have several years of data analysis ahead of them. The accelerator physicists had just killed their baby. At a particle accelerator, losing beam—intentionally or unintentionally—is an everyday occurrence. For accelerator physicists, not trying to get it back is almost unthinkable.
Bob Mau, who was head of the Operations Department for 34 years and came out of retirement to emcee the shutdown ceremonies from the Main Control Room, told me that he was proud of keeping his composure through the official event but fully expected to wake up crying in the middle of the night. “I’ve been here since the beginning,” he said. “I have a lot of emotions tied up in this machine.” When I asked Ron Moore, the head of the Tevatron Department and the man behind the machine’s Twitter feed, how he felt, he said with a kind of frantic laugh, “Well, I didn’t lose it!” He was leaving Fermilab the next day for a job at Massachusetts General Hospital, where he will be operating a cyclotron that makes the radioactive isotopes used in PET scans.
Bittersweet was definitely the word of the day, as collaborators who hadn’t seen one another in years met each other’s children and exchanged plans for the future. Many had already moved on to new experiments and had traveled back to Fermilab just for the celebration. As Brendan Casey, a DZero scientist who is beginning to work on Fermilab’s new muon g-2 experiment, said, “It feels like a reunion, bringing everybody back together and having one last hurrah.” And just as the scientists who worked on and with Fermilab’s most powerful accelerator are moving on to new jobs, new questions, and new frontiers, the Tevatron itself isn’t going to get much rest. After as much of its infrastructure as possible is repurposed into Fermilab’s new experiments, a section of the accelerator, along with the house-sized CDF and DZero detectors, will become an educational exhibit for the public.
At the Irish wake that closed out the day of celebrations, about 20 of the younger members of the Operations Department gathered around a backyard fire and raised their whiskey glasses to cowboys like Fermilab’s founding director Robert Wilson, whose idiosyncratic leadership powered the laboratory through its early years and set the stage for the construction of what seemed at the time like an impossible machine—a machine that, as current lab director Pier Oddone pointed out earlier in the day, had “exceeded every expectation ever set for it” and ran strong until the very end. As the young operators vowed to live up to the legacy the Tevatron leaves behind, I thought of what Casey had said to me the day before about transitioning from DZero to his new muon work: “We did some great physics. Now let’s do some more.”