Fermilab, Batavia, Illinois, USA
EPFL, Lausanne, Switzerland
CERN, Geneva, Switzerland
Electron lenses are a mature technique for beam manipulation in colliders and storage rings. In an electron lens, a pulsed, magnetically confined electron beam with a given current-density profile interacts with the circulating beam to obtain the desired effect. Electron lenses were used in the Fermilab Tevatron collider for beam-beam compensation, for abort-gap clearing, and for halo scraping. They will be used in RHIC at BNL for head-on beam-beam compensation, and their application to the Large Hadron Collider for halo control is under development. At Fermilab, electron lenses will be implemented as lattice elements for nonlinear integrable optics. The design of electron lenses requires tools to calculate the kicks and wakefields experienced by the circulating beam. We use the Warp particle-in-cell code to study generation, transport, and evolution of the electron beam. For the first time, a fully 3-dimensional code is used for this purpose.
Fermilab, Batavia, Illinois, USA
CERN, Geneva, Switzerland
Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. This project is moving towards a technical design in 2014, with the goal to build the devices in 2015-2017, after resuming LHC operations and re-assessing needs and requirements at 6.5 TeV. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles.
Fermilab, Batavia, Illinois, USA
Northern Illinois University, DeKalb, Illinois, USA
The Advanced Superconducting Test Accelerator (ASTA) is under construction at Fermilab. This accelerator will consist of a photo-electron gun, injector, ILC-type cryomodules, and multiple downstream beam-lines. Its purpose is to be a user-based facility for Advanced Accelerator R&D. . Following the successful commissioning of the photoinjector gun, a Tesla style 8-cavity cryomodule and a high gradient capture cavity have been cooled down to 2 K and powered commissioning and performance characterization has begun. We will report on the commissioning status and near-term future plans for the facility.