OBSERVATION OF COLLECTIVE EFFECTS IN THE MULTIPHOTON IONIZATION OF ATOMIC DEUTERIUM

Istituto Nazionale di Fisica della Materia e Dipartimento di Fisica, Universita`di Pisa, Piazza Torricelli 2, 56126 Pisa, Italy~Received 20 October 1997!The yields and time-of-flight spectra for ions produced in three-photon ionization of atomic deuterium havebeen investigated as a function of laser intensity from 0.4 to 200 MW/cm