On the compensation of solenoid field effects by quadrupole lenses

A theoretical possibility is shown of compensating the influence of solenoid models on particle motion in storage rings by means of quadrupole lenses only, which is indispensable in case that solenoids are used for longitudinal particle polarization within the region of interaction. A method is proposed to construct various compensation schemes, in which the perturbation of motion is localized on a small part of the storage ring perimeter and particle motion remains unchanged outside of this part. The described method permits to obtain longitudinally polarized colliding beams by relatively simple means for facilities, which are already in operation. Some versions of solenoid field compensation were checked, which might serve for longitudinal polarization. (orig.)