|
 |
|||||||||||||||||||
|
|||||||||||||||||||
|
|||||||||||||||||||
 |
 |
|
|
Northern Illinois University, Department of Physics, DeKalb, Illinois, USA Fermi National Accelerator Laboratory, Batavia, Illinois, USA
Address for correspondence: Courtlandt L. Bohn, Department of Physics, Northern Illinois University, DeKalb, Illinois, USA. Voice: 815-753-6473; fax: 815-753-8565. clbohn{at}niu.edu
During the last couple of years of his life, Henry Kandrup became intensely interested in using charged-particle beams as a tool for exploring the dynamics of evolving galaxies. He and I recognized that both galaxies and charged-particle beams can exhibit collisionless relaxation on surprisingly short time scales, and that this circumstance can be attributed to phase mixing of chaotic orbits. The chaos is often triggered by resonances caused by time dependence in the bulk potential, which acts almost identically for attractive gravitational forces as for repulsive electrostatic forces superposed on external focusing forces. Together we published several papers concerning evolving beams and galaxies, papers that relate to diverse topics such as the physics of chaotic mixing, the applicability of the Vlasov-Poisson formalism, and the production of diffuse halos. We also teamed with people from the University of Maryland to begin designing controlled experiments to be done at the University of Maryland electron ring. This paper highlights our collaborative findings as well as plans for future investigations that the findings have motivated.
Key Words: chaos • N-body problem • nonlinear dynamics • collisionless • halo
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
 |
