Abstract
It is shown for the first time that the theoretical model for the collisional l mixing in atomic intermediate Rydberg states proposed by de Prunele and Pascale (1979) can also be applied to J mixing in the intermediate Rydberg states with higher quantum defect delta l values and not only to collisions with noble gas atoms and N2 but also with ground-state alkali atoms. The model is applied to the calculation of J-mixing cross sections of nD Rydberg states of Rb (n=7-10) and Cs (n=9-23) perturbed by noble gas atoms and N2. J mixing in Cs(nD)-Cs(6S12/)(n=11-23) collisions is also considered. The agreement with the available results is rather good.