NEW METHOD OF HELMHOLTZ COIL ALIGNMENT

A new alignment method for Helmholtz coils is proposed. This method is based on a probe, whose axis is the same as the alignment axis. This probe includes one magnetic sensor, whose position is slightly shifted from the probe axis, and which is set perpendicular to the axis. Usin g this probe, the tilt and shift of the magnetic centre of Helmholtz c oils can be aligned to within an order of 0.1 mrad and 0.1 mm, respect ively. Moreover, by this method, effects of terrestrial magnetism and tilt of the magnetic sensor can be removed from the measurement. This alignment method is presented along with an estimate of the alignment accuracy of the SPring-8 linac injector.