Space charge, halo and loss in high-intensity hadron beams

4 problems

• Can electron lenses compensate space charge in hadron rings

  Open

  A low-energy electron beam overlapping the proton beam can partly cancel the protons' mutual repulsion; whether this raises the usable intensity in practice is unknown.

• Predicting halo population and fractional loss in megawatt proton linacs

  Open

  Simulations cannot yet predict the tiny fraction of protons that escape the core of an intense linac beam, which is what matters for radiation damage.

• Does nonlinear integrable optics raise the space-charge limit

  Open

  Special magnet arrangements keep particle orbits regular even when they are nonlinear; whether they still help when the beam's own repulsion is included is unknown.

• Maximum tolerable space-charge tune shift in synchrotrons

  Open

  Rings tolerate only a limited spread of particle oscillation frequencies caused by space charge before losses grow; this limit is known only empirically.