Exhaustive search of field defect compensation and reading errors in A.G. machines

This paper reports that the methods usually considered for closed orbit correction in alternating gradient machines are probably not satisfactory for LEP for the vertical plane because the harmonics created may destroy the polarisation. Therefore it seems a priori interesting to correct locally the horizontal field defects. The authors then revised a method used a long time ago to detect alignment errors in the ISR and tried to push it as far as possible towards a full orbit correction