CERN Accelerating science

Article
Title	Impedance Calculation for Ferrite Inserts
Author(s)	Lee, Shyh-Yuan ; Breitzmann, Sara ; Ng, King Y
Affiliation	(Fermilab, Batavia, Illinois) ; (IUCF, Bloomington, Indiana)
Publication	2005
In:	21st IEEE Particle Accelerator Conference, Knoxville, TN, USA, 16 - 20 May 2005, pp.2818
Subject category	Accelerators and Storage Rings
Abstract	Passive ferrite inserts were used to compensate the space charge impedance in high intensity space charge dominated accelerators. We study the narrowband longitudinal impedance of these ferrite inserts. We find that the shunt impedance and the quality factor for ferrite inserts are inversely proportional to the imaginary part of the permeability of ferrite materials. We also provide a receipe for truly passive space charge impedance compensation and, at the same time, avoiding the narrowband microwave instabilities.