Physics of Spin-Polarized Media

Abstract

Abstract : The work supported by this AFOSR grant focused on fundamental physics and the applications of spin-polarized species. Some of the most notable accomplishments were as follows: (1) using optically pumped alkali-metal vapor to polarize the nuclei of solid materials; (2) making much simpler atomic clocks with the physics of push-pull optical pumping, an efficient new pumping method that the authors discovered during the course of the grant; (3) nonlinear pressure of atomic clock frequencies due to the formation of van der Waals molecules; (4) the discovery and interpretation of unexpected signal reversals of magnetic resonance lines used in atomic clocks; (5) a new method of filling atomic clock and magnetometer cells by electrolysis through the glass walls; (6) new investigations of optical pumping and magnetic resonances of spin-polarized metastable xenon atoms; and (7) the discovery of universal contaminants of the alkali metal used in atomic clocks and magnetometers. Most of the work supported by this AFOSR grant has had and will continue to have applications to technologies of importance to the Department of Defense and to the U.S. Air Force. For example, atomic clocks based on push-pull pumping have substantially fewer parts and higher signal-to-noise ratios than conventional atomic clocks. They can be more stable, smaller, less expensive and consume less electrical power than conventional atomic clocks, and they could be used to improve the performance and decrease the cost of geolocation systems. Sections are as follows: Spin-transfer optical pumping of solids, Photonic clocks, Hyperfine frequency shifts due to van der Waals molecules, Signal reversal of magnetic resonances, Electrolytic cell filling technique, Magnetic resonance for spin-polarized metastable xenon atoms, and Contaminants of alkali metals.