Optical cooling of atomic hydrogen in a magnetic trap

We describe the prospects for optical cooling of magnetically trapped atomic hydrogen. We analyze the performance of an optical system currently under development in our laboratory and present calculations for the optical cooling rate. We conclude that by using optical techniques hydrogen can be cooled to below 10 mK while the density is simultaneously boosted to approximately 1014 cm−3. The same system can be used for thermometry down to temperatures well into the microkelvin regime.