| DATE: |
2005-09-08 13:30 - 15:30 |
| PLACE: |
Building 2, No.203 |
| TITLE: |
Accelerator Physics Seminar [ Dipole beam breakup electron cloud instability of a relativisticpositron bunch with a smooth model linear density ] |
| CONTACT: |
ohmi post.kek.jp |
| SPEAKER: |
D.V. Pestrikov (Budker Institute of Nuclear Physics) |
| LANGUAGE: |
English |
| ABSTRACT: |
We study the beam breakup instability of the dipole coherent oscillations of
the relativistic positron bunch interacting with initially unperturbed
electron cloud. We assume a special distribution of the linear density of
positrons along the bunch which enables the calculations of analytic
solutions of the linearized equations of motion of the cloud electrons. With
these assumptions equations describing centroid beam breakup oscillations of
the cloud and of the bunch can be solved taking into account effects of the
cloud pinching and associated BNS damping. Although the BNS damping does not
eliminate the electron cloud instability of coherent oscillations of the
bunch, it changes the dependencies of the coherent oscillation amplitudes on
the time from the quasi-exponential to the power function ones.
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