Measurements of synchro-betatron coupling by an RF cavity in CESR

It is shown that the synchro-betatron resonances encountered in CESR (Cornell Electron Storage Ring) operation are not related to integer tunes, making quantitative analysis difficult. They are strongly affected by closed orbit bumps in the RF cavity. A measurement of the strength of the parasitic deflecting modes using the kick imparted to the beam is in reasonable agreement with a computer calculation of the transverse wake function. >