Universities Help on the Tevatron

From Fermilab Today, February 10, 2005.

This article is the fifth in a series that focuses on the benefits of Fermilab/University collaboration on different accelerator projects.

Many university accelerator projects involve solving problems or improving performance. "Accelerator physicists work on a tight schedule," said Alvin Tollestrup of Fermilab's Experimental Particle Physics Division. "Most universities have little experience with the accelerator environment - the 24-hour monitoring and all the potential repercussions of the system on other experiments."

Kip Bishofberger with a prototype of the TEL electron gun.

One successful collaboration includes the building of the Tevatron Electron Lens (TEL), which started in 2000 at the beginning of Run II. The TEL, attached to the Tevatron, performs two functions. When opposing proton and antiproton bunches collide, only a few particles actually interact, but the other particles are slightly scattered. In "beam-beam compensation" the TEL shoots an electron beam that interacts with the antiprotons, which reverses this scattering and keeps the bunches compact. Additionally, the TEL "sweeps out" particles that have escaped from the bunches into the abort gap, an issue that otherwise would severely handicap the Tevatron.

"The TEL is the only thing in the Tevatron that can be adjusted fast enough to target each bunch independently," said Bishofberger. "After installing it, we succeeded in our goals within a couple months. Today, the first TEL is being used continuously and a second TEL is being built. I'm so excited to be part of a project that has such an immediate effect on today's colliders. It's making a difference right away."

Other university groups contributing to Tevatron performance include Ludovic Nicolas from the University of Glasgow, who is working with Nikolai Mokhov on beam vacuum effects as well as radiation background simulations. "Fermilab is like a great playground for students doing research," said Nicolas. Also, Jia Ning from the Illinois Institute of Technology is working with Chen-Yang Tan of the Accelerator Division on a transverse beam frequency response simulator, which will conserve machine studies time. Carol Johnstone and Valeri Lebedev of Fermilab's Accelerator Division have worked with Michigan State University students on beam lattice calculations, as well.