Mössbauer effect following coulomb excitation measurements of electric quadrupole moment ratios in the first excited 2+ states of 182,4,6W

M�ssbauer conversion spectroscopy: Measurements on the first excited states of180, 182W and145Pm

“…The uncertainty of the electric field gradients can be avoided by comparing the quadrupole splitting ratio of two isotopes in the same compound with the ratio of (B (E2)) 1/2 values. The predicted deviations [4] from rotational model for the isotopes 182W and 186W (7.6 ~o) could not be confirmed in earlier experiments [40,43,59,60]. At present, the B(E2)-value of 18~ can be obtained only from lifetime measurements [63] suffering from large errors, so that from a comparison of the isotopes 18~ and 182W a distinction between the rotational and (P+ Q) model is not feasible.…”

“…To test the validity of the rotational model the quadrupole moment ratios of the first excited states in the even tungsten isotopes ~s2-1S6W were investigated in several works [40,43,59,60]. If the hyperfine components are not completely resolved as in the case of the W-isotopes systematic errors in the determination of the quadrupole splitting may result from the uncertainty of the experimental line width and from the use of absorbers of different resonance thickness.…”