Quenching of Cesium Resonance Radiation by Helium

Using the phase-shift technique to measure excited-state lifetimes, upper limits of 1.5 × 10−14 cm3/sec and 3 × 10−14 cm3/sec have been established for the Cs(62P1/2re3/2) + He → Cs(62S1/2) + He quenching rate constants at 350° and 820°K. (In “cross-section” units these are equivalent to 10−19 cm2 upper limits.) The natural lifetimes were measured to be 30.8 ± 1.5 × 10−9 sec and 35.2 ± 1.5 × 10−9 sec for the Cs 62P3/2 and 62P1/2 states.