A magnetron requires an externally applied magnetic field with flux lines oriented parallel to the cathode axis. Is this statement correct?

Introduction:
Magnetrons are crossed-field microwave devices. They use an electric field (radial) and a magnetic field (axial) to control electron motion and generate microwave oscillations. This item checks basic device-physics orientation.

Given Data / Assumptions:

• Cylindrical magnetron with central cathode and surrounding anode cavities.
• Static magnetic field applied externally.
• Vacuum conditions typical for microwave tubes.

Concept / Approach:

In a magnetron, the DC magnetic field is applied along the axis of the cathode (axial direction), while the DC electric field is primarily radial. The crossed E and B fields cause electrons to follow complex cycloidal paths, enabling interaction with RF cavity fields.

Step-by-Step Solution:

Verification / Alternative check:

Standard magnetron diagrams show solenoids or permanent magnets arranged to produce axial magnetic flux through the interaction space.

Why Other Options Are Wrong:

• False/conditional options contradict the fundamental crossed-field design.
• Reflex klystrons are different devices; the statement pertains to magnetrons specifically.

Common Pitfalls:

Confusing magnetron geometry with klystron or TWT structures, where fields and interaction mechanisms differ.

Final Answer:

True