No abstract

Cross sections have been measured for the disorientation of the 3 1D, 4 1D, and 5 1D states of 3He in collisions with the ground state atoms. Oriented n1D state atoms are produced by exciting in a discharge 3He atoms whose nuclei have been oriented by optical pumping. The role of hyperfine coupling is investigated and the theoretical treatment of the effect of collisions on the orientation of the excited atom, which does not require instantaneous recoupling of the nuclear spin I and the electronic angular momentum J after each collision, is presented.

No abstract

Accurate experimental radiative lifetimes, disalignment cross sections, hyperfine constants, and Zeeman g factors are reported for a number of rotational levels of the 3d electronic complex and the nearby doubly excited K1Σg+ state of molecular hydrogen. The 3d complex of states is not a complete basis for calculation of the above molecular properties. A theory of the Hanle effect in the presence of hyperfine structure is presented.