Metastability exchange optical pumping low field polarizer for lung magnetic resonance imaging

An extensive improvement of our low field polarizer is described. It produces 3He gas polarized up to 40% in a 6 h decay time storage cell. Production rate was raised by a factor of 10 to 4-5 scc/min thanks to the implementation of a new 10 W laser and a new design of a peristaltic compressor, easier to handle. Some applications of polarized gas are also presented: dynamic images of gas inhalation in the rat as well as a static image of human lungs using hyperpolarized gas were obtained.