Methodical errors in tuning accelera 'ng structures of quadrupole HF focusing using the pe' urbation method

This paper gives the analysis of meth dical errors in tuning the accelerating str ctures with RF quadrupole focusing using the pertUrbation 'ethod. These methodical errors are caused by no homogeneous geometry of the accelerating channel and displacemen of perturbation body from its axis. The formulae for ca culating the formfactor for metal sphere in nonuniform e ternal field of an arbitrary configuration has been de uced. The estimation of maximum error for spatial-uniform quadr pole accelerating channel is given