Relaxation rates of the monopole, magnetic dipole, and electric quadrupole moments of the31Pstate of helium

Abstract

The relaxation rates of the monopole, magnetic dipole, and electric quadrupole moments have been determined for the $3^1$P state of helium excited by electron impact, The data are determined from atomic lifetimes using linear and circular polarization analyzed radiation with the electron-photon delayed coincidence technique. This has permitted the direct observation of the time dependence of all the off-diagonal elements of the density matrix of the excited state. The implications for atomic state information determined from polarization and angular correlation methods are indicated.