The creation of $M_L$ alignment due to the foil excitation process is demonstrated with the observation of zero-field quantum beats in He $3{}_{}{}^3{}_{}{}^{}P-2{}_{}{}^3{}_{}{}^{}S$ 3880-Å, hydrogen ${\mathrm{H}}_{\alpha }$, and hydrogen ${\mathrm{H}}_{\beta }$ emission.

• Received 4 May 1970

DOI:https://doi.org/10.1103/PhysRevLett.25.325