COLLECTIVE EFFECTS IN THE IONIZATION OF CALCIUM ATOMS FOLLOWING RESONANT LASER PUMPING OF 4S4P P-3(1) METASTABLE STATE

The ionization of calcium atoms resonantly excited to the 4s4p P-3(1) metastable state is investigated. In particular, the influence of vari ous experimental parameters on the total ionization yield and the rate of its growth are reported. Maximum ionization yield was obtained wit h the buffer gas (Ar) pressure in the range 100-650 mbar. Furthermore, the time history of depopulation of the metastable state 4s4p P-3(1) Monitored in a 'pump' and 'probe' experiment using a second dye laser tuned to the 4s4p P-3(1)-4s5s S-3(1) transition is presented. The effe ctive lifetime of the 4s4p P-3(1) state is shortened to 31 +/- 2 As at 850-degrees-C and 800 mbar Ar pressure from the known value of about 350 mus.