MASER

Microwave Amplification by the of Radiation

Power Matters Some Uses of Masers

• Timing Laboratories • International Time UTC • Local Oscillators for Atomic Fountains • Radio Astronomy • Relativity Experiments • GPS Ground Stations

Power Matters Active Device

Power Matters Maser Block Diagram

28.75 Hz Varactor MPG Control

IF Amp L.O. Multiplier Receiver -105 dBm 5.751 KHz Phase Detector & 5.751 KHz 10 MHz VCXO 14 digit Tuning Maser 10 MHz Synthesizer Physics VaractorPackage Switching 10 MHz Varactor 10 MHz Signal Buffers 10 MHz 405 KHz Cavity Synchronous Register 28.75 Hz Detectors U/D

Source Hydrogen 24 V Power Pressure Source Battery Module Control

110 VAC H supply 110 VAC 2 24-29 VDC Palladium Purifier

Power Matters Maser Diagram

Storage bulb Cavity

Magnetic shields

State selector H

H2 Source bulb Purifier/valve

Power Matters Ground State Hydrogen Atom Energy Level Diagram

Power Matters Magnetic State Selector

Power Matters Hydrogen Storage Bulb

• Centrally located in cavity • Approximately 1-2 Liters • Generally made of Quartz • Teflon Coated – Minimal perturbation to atoms from wall collision • H atoms stay in the bulb about 1 second – Travels on the order of 1 Km – Makes on the order of 10 4 bounces off the wall

Power Matters TE011 Cavity Mode

Loop orthogonal to field line couples signal out of cavityr B

Electric Field Lines Magnetic Field Lines

Power Matters Maser Q’s

∆f • Atomic line Q Q=f/ ∆f 9 –Ql is approx. 2x10 • Cavity Q f –Qc is approx. 40,000 • About 20k needed to sustain oscillation -5 •Qc /Q l is approx. 2x10

Power Matters Active Hydrogen Maser Stability

Power Matters Maser Operating Lifetime

Power Matters Maser Outline

Power Matters Hydrogen Maser Summary

• Very Good Short Term Stability • Low Phase Noise Option • “Mature” Technology • Very Long Service Life • Field Serviceable

Power Matters