Collisional broadening of Rydberg atom transitions by rare gas perturbers

In this paper we present the results and discuss the applicability of an impact theory of lineshapes, developed by Henry and Herman for the pressure-induced broadening and shifting of transitions from the ground state to various Rydberg states of alkalis, to the situation in which the perturbing atoms are ground-state rare gas atoms. This theory, which has successfully described the collisional broadening of Rydberg states by alkali atoms, can without major alterations predict the widths and shifts of Doppler-free two-photon transitions to n S and n D states of Rb and Na, 6⩽ n ⩽30, perturbed by He, Ne, Ar, Kr and Xe. The results in all cases show reasonable agreement with experiment, with the transitions to Na**( n D) states being somewhat less satisfactory than the others.