by Mike Perricone

After nearly a decade of planning and building and fixing, of taking an idea and turning it into two miles of machine, all those connected with the Fermilab Main Injector anticipated the shining moment when the nearly-$230-million accelerator could be declared completed and ready for operation.

That moment came on Wednesday, April 28, when a U.S. Department of Energy Project Acceptance review recommended that DOE confirm Critical Decision 4: Operation of the Main Injector.

And once they got their view of the Promised Land, all those involved with the Main Injector knew they could pause just long enough to take a deep breath, maybe enjoy a quick toast, and then get right back to work the next day.

"We’re already meeting to plan the strategy for our (next) goals, while we have the momentum to do it," said Main Injector commissioning chief Shekhar Mishra.

Setting the stage for the acceptance review, Mishra’s commissioning crews reached the seventh and final commissioning goal on April 27, declaring victory over resonant extraction.

Among its planned uses, resonant extraction is critical to the future success of the MINOS long-baseline neutrino oscillation experiment, sending a beam of neutrinos through the earth to an underground detector 438 miles away in Soudan, Minnesota. The first six commissioning goals were achieved between November and January, but resonant extraction proved a tougher challenge.

"At Fermilab, commissioning is always a ‘24-7’ operation," Mishra said. "We go 24 hours a day, seven days a week, around the clock, three shifts. Weekends. Holidays. In fact all our other commissioning goals were reached on holidays—Thanksgiving week, Christmas Eve, New Year’s Eve."

Those ‘24-7’ and holiday pushes took place in compressed time periods, during lulls in installation activity in the tunnel.

"We actually met our commissioning goals in a very short amount of time," Mishra said. "Initially, we were supposed to have about a year to do this (resonant extraction). In fact, adding up the actual hours we were running, we got about three weeks. Everybody on the commissioning team should be very proud that we’ve delivered all the commissioning goals as we promised to the division and to the Lab management."

Not only was the Main Injector delivered on time, but the cost is expected to be under budget, whether the figure used is the total estimated cost of $229.6 million, or the total project cost of $259.3 million, which includes research and development, pre-operation costs and spare equipment.

As a major bonus, Fermilab delivered another accelerator within the Main Injector’s original schedule and budget: the Recycler, the only machine of its kind in the world, which will save and store antiprotons that would have been discarded after previous collider runs of the Tevatron. Cohabiting the Main Injector tunnel, the Recycler and its permanent magnet technology have won awards for designers Bill Foster and Gerry Jackson, in the areas of accelerator design and energy savings.

Ron Lutha, who has provided oversight as the DOE’s Fermilab Main Injector Project Manager, expressed unreserved admiration during the acceptance review’s closeout session.

"I’ve been associated with this project since 1992," Lutha said. "The management of this project has been very good from the start. When you note the awards this project has gotten, you can see how well it has done. We all look forward to the operation of the Main Injector, and everyone involved with this project should be very proud of it."

The DOE approval did come with one reservation: the Lab must complete as quickly as possible a segment within the Tevatron enclosure between F17, the branch point to the Antiproton Source target, and F47, the straight return at the beginning of Aø.

"We started working on that in the afternoon following the meeting," said Main Injector Department head Phil Martin. "People are cranked up to finish this off."

Martin estimates that completing the segment will take about $75,000 and two weeks of total access time during periods when the accelerator is not running.

Beams Division head and Main Injector Project Manager Steve Holmes explained that the transfer segment had been delayed to focus attention on the leaks in the Low Conductivity Water system that surfaced in November 1997, caused by bacteria growth in water that was stored in the system. Holmes said the LCW repairs posed the most serious problem the project had faced, though there had been others along the way.

Among the major challenges: the great blue heron, a protected waterfowl species, had a rookery in the middle of the proposed Main Injector site; serendipitously, the heron switched to a roomier site in the Main Ring just months before the start of construction. There was a major mitigation project for six acres of wetlands, which not only passed muster with the Army Corps of Engineers but also won environmental awards. There were difficulties with the material for magnet coils and magnet steel. There was flooding during the tunnel construction. There was the Recycler magnet compensator material that went down in an Atlantic Ocean shipwreck. And there was the ongoing saga of the transformer that was ordered but never delivered in working order; the Main Injector power system was redesigned to work without it, though the transformer will eventually be replaced because it is needed for better over-all Lab operations.

But with the seal of approval on the Main Injector, the entire Fermilab accelerator complex is near readiness for the upcoming fixed-target experimental run:

n The Booster has been running at record intensity levels, achieving 5x1012 protons per accelerator cycle, which is the level required for Collider Run II.

n The Tevatron has been chilled to super-conducting temperatures, with all magnets ramped up to 800 GeV. The revised Safety Assessment Document, reflecting the machine’s reconfiguration in the Main Injector era, was accepted on May 5. Commissioning of the beam transfer between the Main Injector and Tevatron at 150 GeV (the line has already run beam at 8 GeV and 120 GeV) began on May 7.

n In the Antiproton Source, the Accumulator is essentially reassembled and ready to accept beam. The Debuncher is awaiting components for the stochastic cooling upgrade, set to arrive this fall. The Charmonium fixed-target experiment (E835) will utilize antiprotons in the fall.

n The Recycler installation is complete, with beam fully circulated for the first time on May 4. The next major milestone is achieving 1,000 turns of beam as a performance goal to demonstrate to DOE the effectiveness of the permanent magnet technology.

n The Main Injector will also be running target tests for NuMI (Neutrinos at the Main Injector), placing some of the candidate target material into the Antiproton Target area, running beam to the target, and observing the results.

And throughout the upcoming Fixed Target run, the Main Injector and Tevatron will undergo preparations for Collider Run II; Martin estimates that Run II-related studies will take up about 10 percent of the time devoted to the Fixed Target run.

Martin, Mishra and Holmes are just three of the many people who have been working on the Main Injector virtually from its inception. Martin is the only department head the Main Injector has had. Mishra was the first scientist hired onto the project from outside the Beams (then Accelerator) Division. Holmes has spent more than half his professional career on the project, since the idea began circulating in the late 1980s.

"It’s been an awful long time to keep focused on one project," Holmes said. "But we’ve had a great group, and it’s been a great experience. We’ve always kept the lines of communication open. And we’ve trusted each other."