Fluorescence quenching and the “ring-mode” to “red-mode” transition in alkali inductively coupled plasmas
Abstract
The ring-mode to red-mode transition in alkali metal inductively coupled plasmas (ICPs) (i.e., rf-discharge lamps) is perhaps the most important physical phenomenon affecting these devices as optical pumping light sources for atomic clocks and magnetometers. It sets the limit on useful ICP operating temperature, thereby setting a limit on ICP light output for atomic-clock/magnetometer signal generation, and it is a temperature region of ICP operation associated with discharge instability. Previous work has suggested that the mechanism driving the ring-mode to red-mode transition is associated with radiation trapping, but definitive experimental evidence validating that hypothesis has been lacking. Based on that hypothesis, one would predict that the introduction of an alkali-fluorescence quenching gas (i.e., N2) into the ICP would increase the ring-mode to red-mode transition temperature. Here, we test that prediction, finding direct evidence supporting the radiation-trapping hypothesis.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 23, 2018
- Source ID
- 10.1063/1.5009463
Entities
People
- James Camparo
- Mingxiong Huang
- R. Bazurto
Organizations
- The Aerospace Corporation
- United States Air Force