Finemet versus ferrite-pros and cons

There is a new magnetic alloy called Finemet which has very constant /spl mu/'/sub p/Qf up to /spl sim/2 kG and is very stable at high magnetic flux density and temperature. It may be a good candidate for high-gradient RF cavities. However, it has a rather low quality factor and is therefore very lossy. We compare the pros and cons of Finemet versus the common ferrite, when used in low-energy accelerating cavities, insertion for space-charge compensation, and barrier cavities.