Magnetic counterforce for insertion devices.
In a standard insertion device, such as a wiggler or undulator, the force between two rows of magnets increases exponentially as the gap between the rows decreases. This force is usually managed by a powerful mechanical gap adjustor, sometimes with the aid of springs at small values of gap. This paper is a description of how the magnetic forces can be nulled using auxiliary counterforce magnets.
Carr
Roger
R
Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, CA, USA. carr@slac.stanford.edu