Comparison of Magnetic Field Calculations to Measurements on a CBA 2-In-1 Magnet System

The CBA1 2-in-1 dipole magnet provides a complex system to test field calculation techniques. In particular the quadrupole term in one half of the magnet induced by the operation of the other half of the magnet is studied. A comparison with field measurement data is made for calculated magnetic field harmonics as a function of current for symmetric and asymmetric operations of the two sides of the magnets. The calculations are made using both differential equation solving programs (PE2D, 2 POISSON3) and integration based programs (GFUN).4 These programs are compared to each other and to the measured data.