Single Bunch Longitudinal Instabilities in Proton Storage Rings
نویسنده
چکیده
In this paper we try to explain the single bunch energy spread increasing in a proton storage ring. Different from an electron machine, the random motions of some particles of a bunch are caused by the nonlinear synchrotron oscillations perturbed by the short range longitudinal wakefield. An analytical single bunch threshold current formula has been established to indicate the beginning of the longitudinal random motions. By using kinetic descriptions one shows that the energy spread of the particles which execute random motions will increase, and the energy spectrum width of the random motions will be enlarged with increasing bunch current.
منابع مشابه
Some Observations on Bunch Lengthening
The phenomenon of current dependent bunch lengthening discovered at AC0 and ADONE about seven years ago can be used as an engineering diagnostic tool to examine how the longitudinal electromagnetic field of a beam couples to its surroundings. 1 The importance of isolating such coupling factors is that they may give rise to damaging instabilities. Another practical reason for studying the effect...
متن کاملAn Analysis of BNS Damping Techniques in Storage Rings and Colliders
Transverse instabilities in linacs can be controlled by BNS damping, in which the transverse oscillation frequency is chirped from the head to the tail of the bunch. It has been suggested that this technique could be applied to quasiisochronous rings, such as are proposed for a muon collider. We adopt a reduced phase space model, taking averages over transverse coordinates and with proscribed l...
متن کاملHead-tail instability caused by electron clouds in positron storage rings
In positron or proton storage rings with many closely spaced bunches, an electron cloud can build up in the vacuum chamber due to photoemission or secondary emission. We discuss the possibility of a single-bunch two-stream instability driven by this electron cloud. Depending on the strength of the beam-electron interaction, the chromaticity and the synchrotron oscillation frequency, this instab...
متن کاملMitigation of the Electron-cloud Effect in the Psr and Sns Proton Storage Rings by Tailoring the Bunch Profile∗
For the storage ring of the Spallation Neutron Source (SNS) at Oak Ridge, and for the Proton Storage Ring (PSR) at Los Alamos, both with intense and very long bunches, the electron cloud develops primarily by the mechanism of trailing-edge multipacting. We show, by means of simulations for the PSR, how the resonant nature of this mechanism may be effectively broken by tailoring the longitudinal...
متن کاملTRANSVERSE AND LONGITUDINAL COUPLED BUNCH INSTABILITIES IN TRAINS OF CLOSELY SPACED BUNCHES’ K. A: THOMPSbN AND R. D. RUTH
Damping rings for the next generation of linear collider may need to contain several bunch trams within which the bunches are quite closely spaced (1 or 2 RF wavelengths). Methods are presented for studying the transverse and longitudinal coupled‘bunch instabilities, applicable to this problem and to other cases in which the placement of the bunches is not necessarily symmetric.
متن کامل