Abstract

It is well known that the specific mean power in a copper vapor laser falls considerably when scaling from a small-bore tube to a large-bore tube. Several mechanisms were proposed to explain this fact. The major ones are thermal population of the lower laser levels due to excessive heating of the gas and disturbance of the plasma relaxation by long diffusion time to the walls. We found that the combination of the high gas temperature and the high residual electron density results in high electric conductivity, especially near the tube axis. Thus the diffusion constant of the electric field decreases, and in a large-bore tube only a small portion of the electric field penetrates into the plasma.

© 1994 IEEE