Determination of ground-level depolarization rates by transmission Zeeman beat spectroscopy: Application to Sm I4f66s2F17

A polarization technique based on the detection of Zeeman quantum beats in transmission is applied to the determination of multipole relaxation rates in ground or near-ground atomic levels. With an appropriate choice of polarization and geometry, beat signals are obtained whose decay directly yields the relaxation rates of orientation or alignment. The technique has been used to study collisional depolarization in the $4f^{6}6s^2{}_{}{}^7{}_{}{}^{}F_1^{}{}_{}{}^{}$ near-ground level of Sm I by rare-gas perturbers. Derived cross sections are compared with previous, widely differing determinations.