Vapor‐cone angles of neutrals and ions emanating from the cathode of a dc mercury vacuum arc

摘要

A stream of ions and neutrals emerges from the cathode of a vacuum arc discharge. Measurements made on a spot‐anchored dc mercury vacuum arc show that, beyond the region of heavy‐particle collisions, ions and neutrals are confined to the same circular vapor cone, and that the angle of this cone depends on the electron‐to‐atom emission ratio. This result is interpreted as indicative of the generation of the ions at the cathode spots in the form of highly directional vapor jets.