Lamb shift and fine structure of3sS3−3pP3in N VI

Abstract

Using beam-foil excitation we have measured the absolute wavelengths of the transitions $3s{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}-3p{}_{}{}^3{}_{}{}^{}P_{0,1,2}^{}{}_{}{}^{}$ in N VI. The difference between the measured and calculated wavelength of the transition from ${}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ is atrributed to the sum of the Lamb shifts of the upper and lower levels. This sum is compared with the recent calculations of Ermolaev and tends to verify the unexpectedly large Lamb shift of the ${}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$ level.