Part II : Optically Pumped Magnetometer System Example: ASQ-81

Part II for Heisenberg Energy-Time Uncertainty Principle Estimate of Optically Pumped Magnetometer Sensitivity: Optically Pumped Magnetometer System. Uses the discussion from Part I to explain the operation of an optically pumped magnetometer with helium-4 as the working substance and gives a reasonable detailed description of the various components of an actual optically pumped magnetometer known as the ASQ-81. The ASQ-81 is an airborne magnetometer used in anti-submarine warfare (ASW) to detect a submerged submarine but is also used as a research tool for measuring the magnetic fields from ocean waves, micropulsations in the Earth’s magnetic field and magnetic field of magnetized geology over the land and oceans. A method for sweeping the frequency of a voltage controlled resonance oscillator to generate a signal for a phase sensitive detector to keep the unit locked onto a resonance is described, followed by a description of a frequency converters purpose in displaying a signal. Actual close-up photographs of a 50 year old ASQ-81 system, known as a STEM system for System Test and Evaluation Model, are shown and a detailed description of its components is given. Errata: The discussion involving directions cosines was said to give the signal S but it is S time the sum of the direction cosines that produces S. In discussing very advanced work utilizing optical pumping in regards to the “Lorentz Violation”, the 2500 nT along the vertical axis should have been 2500 fT. Andrew R. Ochadlick Jr. received a Ph.D. from the State University of New York at Albany (SUNYA) and is a career physicist with university, government and industry R&D experience and teaching experience at the undergraduate and graduate level. He may be reached at [e-mail] .