Faster, Higher, Cooler...

The development and construction of the second-generation batch-mode automated Xe-129 hyperpolarizer allowed the scientists to test new production protocols on the clinically relevant scale, i.e. ~1 liter per batch. The ultimate goal was to improve the overall speed, the degree of Xe-129 hyperpolarization (i.e. achieve higher nuclear spin polarization), while running the optical pumping cell in cooler temperature regime during the last phase of the production/hyperpolarization cycle. The latter minimizes Xe-129 hyperpolarization losses during the cool-down phase, because it can be accomplished faster, and therefore the relaxation related losses can be significantly reduced. This research project resulted in the development of the ramped-temperature hyperpolarization cycle procedure for the operation of match-mode Xe-129 hyperpolarizer, which consists of three steps: (i) fast phase of Xe-129 polarization build-up at the highest temperature sustainable, (ii) second phase at the temperature regime corresponding to the maximum equilibrium Xe-129 hyperpolarization, and (iii) the lower temperature regime, when Xe-129 polarization continues, yet the pumping cell is being prepared for contrast agent transfer to a Tedlar bag. These advances were published in the Analytical Chemistry in 2014. Read the details in the article PDF available in the open access at the American Chemical Society web site: http://pubs.acs.org/doi/pdf/10.1021/ac501537w