Zeeman Effect ofJ=2States of Sr:g-Factor Variation for Interacting Rydberg Series

Measurements of the $g$ factor for a series of bound, $5snd$ $J=2\mathrm{}$ states in Sr, in the region of an avoided crossing between ${}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}D_2^{}{}_{}{}^{}$ Rydberg series, show a variation which is in agreement with the prediction of multichannel quantum-defect theory. The $g$ factor was measured by multiphonon ionization spectroscopy. The dependence of ionization signal on laser polarization was also studied.