Penning and associative ionization in crossedhyphen;beam Na/Na collisions assisted by strong resonant laser fields

摘要

We observe the production of Na2+and Na+arising from single collisions between crossed beams of sodium atoms when a laser field is tuned near the Na(3pthinsp;2P3/2) and Na(3pthinsp;2P1/2) transitions. Measurements of ion intensity vs laser intensity show that at moderately high power true laserhyphen;induced processes dominate over purely collisional effects. Relative intensity of masshyphen;selected ions produced at either member of the Na resonance doublet shows conclusively that Na+does not arise simply from photodissociation of Na2+but must result from a direct, laserhyphen;induced collisional ionization.