Spin and Coherence Transfer in Penning lonization
The Penning ionization process has been effectively used as a mechanism for energy transfer from one species to another. Penning processes are special cases of collisions of the second kind in which a portion of the internal energy of the first species is utilized to ionize and excite the second species. This mechanism has been successfully applied in the He-Cd and He-Zn lasers, in which the laser levels are excited states of the Cd or Zn ions which have been populated by the Penning collision between helium metastable atoms and the Cd or Zn ground-state neutral atom. The Penning process has also been used as a convenient and efficient source of ground-state ions. In a recent series of measurements(1) ensembles of ground-state ions of Mg, Ca, Zn, Sr, Cd, and Ba were formed with sufficient densities to perform conventional Hanle experiments. In this way the radiative lifetimes and depolarization cross sections of the first excited 2 P 3/2 states of the ions were determined.
KeywordsOrbital Angular Momentum Radiative Lifetime Magnetic Resonance Signal Spin Angular Momentum Coherence Transfer
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