Estimation of broad band impedance of the SPring-8 storage ring

Transverse coupling impedance of the storage ring at the European Synchrotron Radiation Facility

“…However, apart from cavitylike structures, most geometries, in particular, low-gap chambers equipped with tapers, are of concave form and cannot be dealt in this manner (keeping the integration path on the border of the exit tubes the path would traverse zones outside of the tube and becomes useless). The usual way [19] to overcome this problem is to invert the geometry, i.e., to exchange the larger outer beam tubes with the inner low-gap chamber. This is called the indirect method.…”