BNL, Upton, New York, USA
In this paper we present an expansion of the technique of characterizing nonlinear optics from off-energy orbits (NOECO) to cover harmonic sextupoles in storage rings. The existing NOECO technique has been successfully used to correct the chromatic sextupole errors on the MAX-IV machine, however, it did not account for harmonic sextupoles, which are widely used on many other machines. Through generating vertical dispersion with chromatic skew quadrupoles, a measurable dependence of nonlinear optics on harmonic sextupoles can be observed from hybrid horizontal and vertical dispersive orbits. Proof of concept of our expanded technique was accomplished by simulations and beam measurements on the National Synchrotron Light Source II (NSLS-II) storage ring.
