DEFLECTOR FOR CHARGED PARTICLE RAYS

摘要

PURPOSE:To enable a rotationally constant coil having a high deflectional sensitivity to be prepared with high accuracy and at low cost by forming deflection coils and correction coils on the same thin insulation film before it is wound around a cylinder. CONSTITUTION:Conductive patterns 2 and 2' are respectively formed on the front surface (a) and the back surface (b) of an insulating thin film 1 of around 20-30mum thickness. A rotationally-constant saddle-type coil having two pairs of coils with an opening half-angle difference of 60 deg. is obtained by winding the thin film 1 around a cylinder in such a manner that (A) and (B) respectively correspond to (C) and (D). Here, since one conductive patterns of each coil pair is formed on the front surface of the thin film 1 and the other conductive pattern is formed on the back surface, the inner diameter of two coils constituting a coil pair are different by the thickness of the thin film 1. However, since the thickness (20-30mum) of the thin film 1 is very small (about 1/1000) as compared with the inner diameter (20-30mm.) of the coil, it can be practically considered as a rotationally constant coil.