Temperature Dependence of Hyperfine Pressure Shifts. I. Deuterium in Helium from -135 to 400°C

Spin-exchange optical pumping has been used to measure the hyperfine pressure shift of deuterium in helium as a function of temperature. A new technique for optical pumping at low temperatures has been combined with a previously reported technique for optical pumping at high temperatures to make measurements between -135 and 400 ^∘{}C. The experimental results are compared with existing theoretical calculations.