Ultrafast warm-up rubidium reference

This paper describes the accomplishments of a program performed at EG&G to greatly reduce the warm-up time for a rubidium frequency standard (RFS) from minutes to seconds. Typical warm-up times for an RFS range from 1.5 to 10 minutes at room temperature. In some tactical situations, such warm-up times, which may be increased by low ambient temperatures, are undesirable or unacceptable, requiring for example that the RFS be turned on first when setting up a station or be kept “hot” while other equipment is off to conserve power. This program focused on the physics package. The areas that were investigated and improved related to warm-up of the absorption cell (using a design with sapphire faceplates), lighting and warm-up of the rubidium lamp, and servo acquisition and lock. In the final configuration lock was achieved in 7 seconds at +5°C. The modifications made were for engineering evaluation. Additional development is needed before a practical ultrafast warm-up rubidium reference can be produced