*** Slocum 9633485 In Phase I a concept was defined for a novel laser-pumped helium 4 magnetometer. The magnetometer employs a dual mode of operation (vector/scalar) to measure both the magnitude and direction of the geomagnetic field. The key technical component is a patented tunable diode laser (TDL) pumping source. The feasibility of measuring scalar fields with a resolution of 0.3 pT/~Hz, an order of magnitude better than conventional resonance magnetometers, was demonstrated with a laboratory breadboard. The concept of an omnidirectional single cell, single beam sensor was also demonstrated. A concept was also developed for extracting three-axis vector information from the single cell sensor. Phase I results will be used to design, fabricate, demonstrate and characterize a prototype portable Geomagnetic Vector Scalar Magnetometer (GVSM) including the sensor and electronics modules for high resolution scalar mode and three-axis vector mode in Phase II. The GVSM instrument will be the first portable resonance magnetometer to provide vector components and high-resolution scalar field information. It will be state-of-the-art instrumentation for geomagnetic research and exploration. GVSM instrument would also find application in undersea surveillance, anti-shoplifting surveillance, mine countermeasures and planetary and space magnetic surveys. ***
