A method of closed orbit correction under constraint conditions

We have developed the correction algorithm of the closed orbit distortion ( COD) under the constraint condition where beam positions at particular poin ts are not changed. The new algorithm is based on the modified PSINOM algor ithm including the regularization process in order to avoid the inversion p roblem of the ill-posed response matrices. We have confirmed that the COD i s well corrected with no orbit leak in the simulation and is in good agreem ent with the experiment.