The beam-beam effects have been the dominating sources of beam loss and lifetime limitations in the Tevatron proton-antiproton collider [V. Shiltsev et al., Phys. Rev. ST Accel. Beams 8, 101001 (2005)]. Electron lenses were originally proposed for compensation of electromagnetic long-range and head-on beam-beam interactions of proton and antiproton beams [V. Shiltsev et al., Phys. Rev. ST Accel. Beams 2, 071001 (1999).]. Results of successful employment of two electron lenses built and installed in the Tevatron are reported by Shiltsev et al.

A novel modulator has been designed, built and tested for the TESLA test facility.This e+ eaccelerator concept uses superconducting RF cavities and requires 2 ms of RF power at 10 pps. As the final accelerator will require several hundred modulators, a cost effective, space saving and high efficiency design IS desired. This modulator uses a modest size switched capacitor bank that droops approximately 20% during the pulse. This large droop is compcns;~ted for by the use of a resonant LC circuit. The capacitor bank is connected to the high side of a pulse transformer primary using a series CT0 switch. The resonant circuit is connected to the low side of the pulse transformer primary. The output pulse is flat to within I% for 1.9 ms during a 2.3 ms base pulse width. Measured efficiency, from breaker to klystron and including energy lost in the rise time, is approximately 85%.

Abstract. The 8.9-GeV/c Recycler antiproton storage ring is equipped with both stochastic and electron cooling systems. These cooling systems are designed to assist accumulation of antiprotons for the Tevatron collider operations. In this paper we report on an experimental demonstration of electron cooling of high-energy antiprotons. At the time of writing this report, the Recycler electron cooling system is routinely used in collider operations. It has helped to set recent peak luminosity records.

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This paper reports on a 6 kV modulator built and installed at Fermilab to drive the electron gun anode for the Tevatron Electron Lens (TEL). The TEL was built with the intention of shifting the individual (anti)proton bunch tunes to even out the tune spread among all 36 bunches with the desire of improving Tevatron integrated luminosity. This modulator is essentially a 6 kV arbitrary waveform generator that enables the TEL to define the electron beam intensity on a bunch-by-bunch basis. A voltage waveform is constructed having a 7 μs duration that corresponds to the tune shift requirements of a 12-bunch (anti)proton beam pulse train. This waveform is played out for any one or all three bunch trains in the Tevatron. The programmed waveform voltages transition to different levels at time intervals corresponding to the 395 ns bunch spacing. Thus, complex voltage waveforms can be played out at a sustained rate of 143 kHz over the full 6 kV output range. This paper describes the novel design of the inductive adder topology employing five transformers. It describes the design aspects that minimize switching losses for this multi-kilovolt, high repetition rate and high duty factor application.