Lifetime of the first P11 state of zinc, calcium, and strontium

The lifetime of the first excited P11 state of zinc, calcium, and strontium has been measured by the zero-field level-crossing technique. The results are: zinc (P11)=1.410.04×10-9 sec, calcium (P11)=4.480.15×10-9 sec, and strontium (P11)=4.970.15×10-9 sec. The results are compared to earlier experimental results and also to theoretical predictions. It is found that our results are in excellent agreement with the Bates and Damgaard Coulomb approximation method for estimating the oscillator strengths. © 1964 The American Physical Society.