"Spin Polarized Gases"
William Happer
Princeton

Abstract

The gases He-3 and Xe-129, mixed with small amounts of alkali-metal vapors, can have their nuclear spin polarizationincreased from the normal values of a few parts per million to many tens of percent by spin exchange optical pumping. The gases are finding important applications in medical imaging of human lungs and other diagnostic applications. These applications and the physics behind them will be discussed in the colloquium.