Physics Colloquium

The ability to use lasers to cool atoms to micro-kelvin temperatures and to subsequently control their quantum mechanical behavior1 has led to the development of exquisitely precise 'quantum' sensors.2 Applications of these sensors include the measurement of local gravitational anomalies to unprecedented accuracy and very accurate, highly stable gyroscopes.
Our LLNL - AOSense, Inc. collaboration is pursuing diverse applications of these sensors that directly exploit their extraordinary scale factor stability, low noise and bias drift characteristics. These applications include shielded threat detection in passing vehicles, emergency response, and treaty verification, all of which require rapid, passive methods to determine hidden mass configurations precisely and/or verify the masses present in containers. Such dense, localized objects can in principle be discovered and accurately measured by their effect on the local gravitational field.3 Furthermore, near field measurements of these gravitational perturbations from multiple vantage points allow for a kind of gravitational 'tomography,' leading to the real-time determination of the hidden mass distribution.
Additionally, we are interested in the potential of atom interferometer Sagnac gyroscopes to do accurate 'dead reckoning' navigation without the aid of GPS.4
After reviewing the physics of atom interferometry in atomic fountain-Mach-Zehnder and Sagnac configurations, I will describe the development of a 'gravity tomography' signal analysis system for vehicle portals, including the optimal synthesis of the gravitational sensor signals with complementary radiation detection.