An Examination of Magnetic Fields from Cathode Heaters

Presented here are analytic results obtained using Field Precision´s Magnum FEA code of the DC magnetic field at an X-axis line 0.078 inches (2 mm) from a planar emitter face and at a Z-axis line at a point on the circumference. Results are presented in relative terms, as the analyses assume a specific current and wire length, items which are, from one heater design to another, not generally interchangeable. Also presented is a subjective yet practical comparison of some of the strengths and weaknesses of each coil