Performance of magnetically compressed O-type electron beams emitted from nonshielded cathodes

The theory pertaining to the behavior of a cylindrical electron beam emitted from a nonshielded cathode in an axial, monotonically increasing magnetic field is experimentally verified. A convenient technique of measuring the scalloping of electron beams in sealed-off tubes by varying the beam voltage is described. Experimental results include the study of the beam compression and percentage scalloping in several configurations of increasing magnetic fields. It is shown that for such beams the percentage scalloping is fairly independent of the amount of compression.