To those who worked there, the Tevatron is "more than a machine, it's a living creature that has the ability to see the microscopic quantum world," CDF scientist Ben Kilminster - who was in the 5th grade when the Tevatron first came online in 1985 - said as he and his team shut down their detector. "So it's going to be with heavy hearts that many of us watch it close its eyes to this world that has captivated us for so long."
Now Fermilab will enter a new post-Tevatron era of what Oddone calls the "intensity frontier": packing as many particles as possible into the smallest possible beam, enabling high-precision measurements to aid in the search for very rare processes in nature.
Future experimental efforts will focus on neutrinos, cosmic rays, muons and kaons, and the ongoing search for dark matter and dark energy, as well as potential spinoff technologies for clean nuclear energy and handling nuclear waste.
All good accelerators eventually give way to bigger, more powerful machines, and I don't know any physicist who begrudges the passing of the worlds-highest-energy torch to the Large Hadron Collider. What's different this time around is that there is no US-based machine waiting in the wings to take its turn. Good physics will continue to be done, but America has largely ceded its leadership role in particle physics.
That would make Robert Rathburn Wilson, the very first director of Fermilab, very sad. When it was first being built, he made sure to make room for a small herd of American bison to live on the grounds, representing the frontier of physics. Wilson resigned in 1978 in protest over funding cuts for the lab, just before construction began on the Tevatron.