ISSN:
1434-601X
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract A differential measurement of the spin rotation of Dy160 in the 2+ rotational state was performed by using liquid sources of TbCl3 solved in 3M HCl and applying an external magnetic field of 33 500 Gauss. No change of the Larmor precession frequency could be detected within the first 10·10−9 s. It is concluded that the ground state of the electronic shell of Dy+++ is reached in 6·10−10 s after theβ-decay of Tb160. The valueg R=+0.364±0.011 was derived using 〈r−3〉eff=8.92 a. u. for the 4f-shell of Dy+++. A comparison with the result ofCohen who studied the Mössbauer-effect in Fe2Dy shows that the value of 〈r−3〉eff must be 10% larger in this compound. A measurement of the effective magnetic field at the position of the nucleus in a source of terbium metal was performed for different temperatures. It revealed a temperature dependence which is very similar to the paramagnetic susceptibility χ(T). We observed a strong attenuation ofγ γ-angular correlations in the 2+ rotational state. For liquid sources of TbCl3 solved in 3M HCl the following attenuation parameters were measured: $$\begin{gathered} \lambda _2 = (0.122 \pm 0.013) \cdot 10^9 {\text{s}}^{ - {\text{1}}} , \hfill \\ \lambda _4 = (0.235 \pm 0.024) \cdot 10^9 {\text{s}}^{ - {\text{1}}} . \hfill \\ \end{gathered}$$ The ratioλ 4/λ 2 deviates from the value which is expected for the attenuation by internal fields of the 4f-electronic shell. Possible reasons are discussed. We derived the following multipole mixtures ofγ-transitions in the decay of Tb160: $$\begin{gathered} \delta (879 {\text{keV) = + 17}}{\text{.7}}_{ - {\text{2}}{\text{.8}}}^{{\text{ + 5}}{\text{.2}}} (M1 + E2) \hfill \\ \delta (299 {\text{keV) = }} - 0.029 \pm 0.005 (E1 + M2) \hfill \\ \delta (329 {\text{keV) = }} - 0.023 \pm 0.007 (E1 + M2). \hfill \\ \end{gathered}$$ The half life of the 2+ rotational state was redetermined as $$T_{\tfrac{1}{2}} = (1.99 \pm 0.04) \cdot 10^{ - 9} {\text{s}}{\text{.}}$$
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01381968
