Calculation of longitudinal and transverse impedances of Ferrite-50 beampipe insert for Cornell B-Factory. Final report

As outlined in M Tigner`s letter to D. Prosnitz (dated 5/16/91), our task was to calculate the longitudinal monopole (m = 0) and the transverse dipole (m = 1) impedances if a simple structure consisting of a beam pipe with a recessed ferrite (Ferrite-50) ring. In support of this goal we also undertook to compute the impedance of a small scale model for which impedance measurements had been made by L. Walling, now of SSCL. To carry out the required calculations we used the AMOS wakefield code together with a recently developed physics package that models dispersive media in the time domain. In conclusion, we found reasonable agreement with Walling`s measurements on the scale model for {ital Z}{sub {parallel}0} and for Re[{ital Z}{sub r1}]. However, there is a qualitative difference between experiment and calculation found for Im[{ital Z}{sub r1}]