Das gyromagnetische Verhältnis des 2⁺-Rotationsniveaus von Hf¹⁷⁸ und weitere Untersuchungen zum Zerfall von W¹⁷⁸

Abstract

The nuclearg-factor of the 2⁺ rotational state of Hf¹⁷⁸ was determined by a measurement of the rotation of the angular correlation between the gamma-group of ∼1350 keV and the 93 keV radiation in an external magnetic field of 49550 gauss. The result is:

$$g_R = + 0 \cdot 356 \pm 0 \cdot 035.$$

Liquid sources of 21 days W¹⁷⁸ (ammoniumtungstate in aqueous solution) in equilibrium with 9.3 min Ta¹⁷⁸ have been used for these measurements.

Differential angular correlation measurements showed the existence of a strong time dependent attenuation. The observed attenuation parameters are:

$$\begin{gathered} \lambda _2 /\lambda = 0 \cdot 85 \pm 0 \cdot 23 \hfill \\ \lambda _4 /\lambda = 0 \cdot 74 \pm 0 \cdot 10. \hfill \\ \end{gathered} $$

The true coefficients of the angular correlation between the gamma-group of ∼1350 keV and the 93 keV radiation were derived as:

$$\begin{gathered} A_2 = + 0 \cdot 330 \pm 0 \cdot 047 \hfill \\ A_4 = 0 \cdot 990 \pm 0 \cdot 060. \hfill \\ \end{gathered} $$

As they are substantially larger than previously published values a reinterpretation of the correlation function is given.

The half-life of the 93 keV state was found to be:

$$T_{\tfrac{1}{2}} = (1 \cdot 49 \pm 0 \cdot 05) \cdot 10^{ - 9} \sec $$

in good agreement with the coulomb excitation data.