Some factors in the design of deflecting coils for cathode-ray beam systems

The paper deals with the deflection of a narrow beam of electrons focused on to a screen beyond the deflecting coils, and its subject matter is applicable to most types of transmitting and receiving cathode-ray tubes in which the deflecting fields exist in an otherwise field-free space. The deflecting coil is first considered as a series of long conductors parallel to the undeflected beam, and the conditions are deduced for the best field distribution. The effect of conductors of finite length and the end turns connecting them are discussed in connection with certain experimental data. The shape of screen surface on which the beam will focus after deflection and the increase of spot size are examined to show the application of the theory to design.