Transverse instability excited by rf deflecting modes for PEP

Technical Report · Thu Nov 01 04:00:00 EST 1979

DOI:https://doi.org/10.2172/6521593· OSTI ID:6521593

Chao, A W; Yao, C Y

We have looked at the possible transverse instability effects which are caused by the deflecting modes of the rf cavities in PEP. The results are obtained by applying the expression of the instability damping rate. We have assumed that there equal bunches equally spaced in PEP. We have worked out the equivalent for a single bunch beam. The effect of chromaticity xi is included as a frequency shift in the bunch mode spectra. We rewrite this result in terms of the transverse wake field instead of the impedance. We include an application of the Sacherer formalism to the case of resistive wall. The resulting expression of the damping rate contains two terms. The first term corresponds to the effect of the short wake fields; it agrees with the result of the head-tail instability as derived by Sands. A numerical estimate of this resistive-wall head tail case for PEP is given. It re-confirms that the resistive wall instability is not a serious problem for PEP. The second term gives the effect of long wake fields and it agrees with the result of Courant and Sessler. 10 refs., 2 figs.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (USA)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 6521593
• Report Number(s): SLAC-PEP-NOTE-321; ON: DE89006350
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
430200 -- Particle Accelerators-- Beam Dynamics
Field Calculations
& Ion Optics
430400* -- Particle Accelerators-- Storage Rings
BEAM BUNCHING
BEAM DYNAMICS
BOLTZMANN-VLASOV EQUATION
DAMPING
DIFFERENTIAL EQUATIONS
ELECTRIC IMPEDANCE
EQUATIONS
EQUATIONS OF MOTION
FEEDBACK
FUNCTIONS
IMPEDANCE
INSTABILITY
LANDAU DAMPING
PARTIAL DIFFERENTIAL EQUATIONS
PEP STORAGE RINGS
RF SYSTEMS
STORAGE RINGS
WAVE FUNCTIONS