Abstract
Singly, doubly, triply, and quadruply charged krypton ions are formed by multiphoton absorption processes in krypton atoms. They are induced by a 50-psec laser pulse at 1.064 μm in the --W- intensity range. The percentage ratio between the numbers of doubly and singly ionized Kr atoms is 10% at 8× W . It is shown that ions result from a direct 33-photon absorption process. At 1.5× W , the 33-photon absorption rate is only about 60 times less than the 13-photon absorption rate which gives singly charged ions.
- Received 12 March 1982
DOI:https://doi.org/10.1103/PhysRevLett.48.1814
©1982 American Physical Society