Isotope shift and hyper fine structure in the spectrum of tin

Shifts between all the even isotopes of tin (Z = 50) have been measured interferometrically, for enriched samples, in the line 3283 $\overset{\circ}{\mathrm A}$ of the spectrum of Sn II. The h.f.s. and shifts relative to the even isotopes of two of the three odd isotopes have also been measured. The results are compared with those obtained by other workers on the tin lines 6454 and 5799 $\overset{\circ}{\mathrm A}$, (i) in order to obtain absolute values of the volume shift constant for the tin isotopes, which involves estimation of the specific mass shift in the lines, and (ii) to calculate the configuration mixing in some of the levels concerned. After allowing for normal mass effect only the measured shifts are: 112-114; 22.0 mK; 114-116, 21.9 mK; 116-118, 18.0 mK; 118-120, 18.4 mK; 120-122, 16.6 mK; 122-124, 11.7 mK; 116-117, 8.4 mK; 118-119, 2.4 mK. A hyperfine doublet was observed in 3283 $\overset{\circ}{\mathrm A}$ for both $^{117}$Sn and $^{119}$Sn; the splittings are 153.6 and 162.3 mK respectively and are attributed to the lower level involved in the transition.