Seminar Details

Select Topics on the Transport of High Intensity Beams

Steve Lund, Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory
Wednesday, October 23, 2:00 PM - Special ASD Seminar
NSCL Lecture Hall

ABSTRACT: Transport of charged particle beams with high intensity in terms of beam power and/or strong space-charge intensity occur in a plethora of applications ranging from how power machines like FRIB, spallation neutron sources, and next-generation light sources, to high space-charge intensity machines associated with beam-driven Heavy Ion Fusion and High Energy Density Physics studies. Such applications require a high degree of beam control to minimize particle losses. This necessitates a detailed understanding of the beam distribution, machine alignment issues, applied fields, halo production processes, and parasitic species effects such as electron cloud issues. Strong space-charge issues commonly occur near injection energy. When space-charge intensity is high, a charged particle beam behaves much as a plasma with the applied focusing forces taking the role of a neutralizing species in a plasma. Collective waves and instabilities can generate excessive halo, degrade beam quality by growing phase-space area, and result in a loss of beam control. Here I overview selected topics relevant to the transport of high intensity beams including: 1) Centroid control in solenoid transport systems. 2) A multipole expansion for realistic numerical simulations of focusing optics using only minimal field data measurements on surfaces. 3) Classes of distributions adapted for quiescent transport at high space-charge intensity. 4) The role of non-tenuous halo processes in space-charge induced transport limits for quadrupole focusing channels.