Stability criterium for periodic solenoidal channel

The stability of a periodic solenoidal channel can be discussed from the absolute values of the transfer matrix eigenvalues of one period of the channel. The same approach is used to study solenoidal channels with alternating polarities and also for channels where the solenoids are described by fieldmaps. Once the lattice is chosen, the method allows to calculate the energy acceptance of the channel. Tracking simulations are used to check the stability conditions.