Key points are not available for this paper at this time.
We have measured the temperature of a gas of sodium atoms released from "optical molasses" to be as low as 4320. Surprisingly, this strongly violates the generally accepted theory of Doppler cooling which predicts a limit of 240. To determine the temperature we used several complementary measurements of the ballistic motion of atoms released from the molasses.
Lett et al. (Mon,) studied this question.