Progress in space charge compensation using electron columns

Space charge compensation allows for increased beam current in linacs and RFQs. A novel application of space charge compensation, the electron column, offers the opportunity to realize more intense beams for high energy physics in circular accelerators. The concept relies on ionization of residual gas by the primary beam, with electromagnetic fields used to confine and shape the space charge neutralizing plasma. Prior experimental efforts and simulation studies are reviewed. They indicate that electron columns could be successfully deployed in accelerator rings. The experimental demonstration of an electron column is underway at the Integrable Optics Test Accelerator at Fermilab. The experiment, instrumentation, and physics program are discussed.