• V. Kamerdzhiev, G.F. Kuznetsov, G.W. Saewert, V.D. Shiltsev, A. Valishev
  Fermilab, Batavia

Tevatron Electron Lenses (TEL) have reliably demonstrated correction of the bunch-to-bunch tune shift induced by long-range beam-beam interactions. The second and most important intended application of TEL is compensation of the nonlinearity of head-on beam-beam force. We report on the first studies of head-on beam-beam compensation with the second generation Gaussian profile TEL. We evaluate the effect of TEL on beam life time and emittance and compare the observed results with simulations.

• V. Kamerdzhiev, G.W. Saewert
  Fermilab, Batavia

Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359

A novel high voltage modulator had been under development for 1.5 years. It was completed tested on the bench and became a part of the TEL2 system in October 2008. The modulator is used to drive the electron gun anode. We provide technical details on the stacked transformer modulator, analyze its performance and discuss the design challenges. The results of the beam studies made possible by the new high voltage modulator are reported.

• V.D. Shiltsev, G.F. Kuznetsov, A. Valishev
  Fermilab, Batavia
• V. Kamerdzhiev
  FZJ, Jülich
• A.L. Romanov
  BINP SB RAS, Novosibirsk

We report preliminary results of experimental studies of "electron columns" in the Tevatron and in a specialized test setup. In the Tebvatron, 150 GeV beam of protons ionized residual gas and ionization electrons are stored in an electrostatic trap immersed into strong longitudinal magnetic field. Shifts of proton betatron frequencies are reported. In the test set, we observe effects pointing to accumulation and escape of ionization electrons.