Spotlight

Michael Ehrlichman
Michael Ehrlichman, graduate student, is working in David Rubin’s group investigating intrabeam scattering and other collective effects in high-current, low-emittance storage rings. His research methods consist of developing beam dynamics simulations and conducting experiments with the Cornell Electron Storage Ring (CesrTA). As the density of particles in a beam increase, many important beam parameters become dominated by multi-particle effects. Intrabeam scattering is one such effect that describes collisions between the particles within the beam bunch. The result is that the size of the bunch depends on its charge (beam current) in a particular way. Another important collective effect is the current-dependence of the betatron tunes. Interactions between the bunch charge and vacuum chamber walls effect both the coherent tune and the spread of tunes within the bunch. As tune varies with beam current, so can beam size, as the particle tunes cross machine resonances driven by nonlinearities in the accelerator guide field. So while it is straightforward theoretically to evaluate the consequences of various collective effects, it is difficult to distinguish them experimentally.

His studies make use of the CESR Test Accelerator (CesrTA) and are directed towards the development of damping rings for future accelerators, in particular the International Linear Collider (ILC).
Damping rings are used to shrink the size of a particle beam so as to maximize the probability of collisions occurring when opposing beams interact.

Michael also studies a similar effect, Touschek scattering, in Energy Recovery Linacs (ERLs). In Touschek scattering, intrabeam scattering manifests itself as particle loss. Here we are concerned with single, large scattering events that result in particle loss, rather than multiple, small scattering events that increase beam size. We are interested in Touschek scattering in ERLs because of the radiation hazard created when lost particles collide with the beam pipe.

Michael hopes that his research will result in better methods for predicting beam behavior in high-current, low-emittance accelerators.

  • Contact

    Department of Physics Cornell University 109 Clark Hall Ithaca, New York 14853-2501 Phone: (607) 255-6016 Fax: (607) 255-2643 General email: physics@cornell.edu

    Laboratory of Atomic and Solid-State Physics (LASSP) 511 Clark Hall Ithaca, New York 14853-2501 Phone: (607) 255-6053 Fax: (607) 255-6428

    Laboratory for Elementary-Particle Physics (LEPP) Newman Laboratory Cornell University Ithaca, New York 14853-2501 Phone: (607) 255-4951 Fax: (607) 254-4552