γ-γ-Richtungskorrelationsuntersuchungen am Zerfall des185Os

Angular correlations of the gamma cascades (592-125), (162-718), (233-646), and (162-592) keV have been measured. The spin of the 879 keV level was found as 1/2. The mixing ratios of the 125, 162 and 718 keV gamma transitions were determined.     

Elektroneneinfang beim Zerfall des Ti45

Electron capture to the 718 keV, 1238 keV, 1408 keV and 1665 keV excited states of Sc⁴⁵ have been observed in the decay of Ti⁴⁵. The branching ratios were determined to be (0,4±0,04)% (0,05±0,02)%, (0,27±0,03)% and (0,08±0,01)% per decay of Ti⁴⁵ respectively.     

Messung des Elektroneneinfang am Kern Ga70

The electron capture of Ga⁷⁰ has been observed using a x-ray semiconductor Ge(Li) detector. Measuring the ZnK x-rays and the 0.1755 MeV gamma-rays from the beta decay of Ga⁷⁰ the transition probability to the ground state ofZn⁷⁰ was found to be 0.24%. The log(ft) value is 4.8. The half-life of Ga⁷⁰ has been found to be (21.15±0.06) min and the energies of the gamma-rays are (0.1755±0.0005) MeV and (1.040±0.003) MeV.     

Experimentelle Untersuchungen am Elektroneneinfang des Mangan 54 und Zink 65

The electron capture decay of Mn 54 and Zn 65 was investigated using Na I(Tl)-detectors. Spectroscopic-coincidence techniques were employed to examine theK-electron capture rates of Mn 54 and Zn 65, the branching ratio and positron rate of Zn 65. The experimental results are:P _k ω _k (Mn)=0.2492±0.0017,P _k ω _k (Zn)=0.3927±0.0026,EC ^* /EC ⁰(Zn)=53.2±1.0/46.8±1.0,γ/β ⁺=35.1±1.7,K ⁰/β ⁺=27.7±1.5. Thus electron capture to the excited state of Cu 65 occurs to the extent of 52.4±1.0% while electron capture and positron decay to the ground state were found to be associated with 46.1±1.0% and 1.49±0.05% of the disintegrations. These data partly disagree significantly from measurements of other authors. Using the fluorescence yieldsω _k (Cr)=0.279 andω _k (Cu)=0.4425, deduced from other measurements, values ofL+M/K of electron capture to the excited state could be derived:L+M/K(Mn 54)=0.120±0.015 andL+M/K(Zn 65)=0.127±0.015. These ratios agree with the calculations ofBahcall. The half-lives of Mn 54 and Zn 65 have been determined to beT _1/2(Mn 54)=312±5d,T _1/2(Zn 65)=243±4d The energy of the Zn 65-γ-rays was measured with a Ge(Li)-counter:E ^γ=1115.5±0.5 keV.     

Experimentelle Untersuchungen am Elektroneneinfang des85Strontium und88Yttrium

The electron capture decay of⁸⁵Sr and⁵⁵Y has been investigated using NaI(Tl)-detectors. Spectroscopic-coincidence techniques have been employed to examine theK-electron capture rates. The experimental results areP _K ω _K (Sr)=.5959 ± 0.0035 andP _K ω _K (Y)=0.6340± 0.0032. Using theK-capture probabilities, derived from the capture ratios ofBrysk andRose with the exchange correction ofBahcall:P _K (Sr)=0.880± 0.008 andP _K (Y)=0.883 ± 0.008, one can derive from these results the fluorescence yieldsω _K (Rb)=0.677± 0.009 andω _K (Sr)=0.712± 0.010. Functions ofω _K (Z) were fitted to recent experimental data and tabulated forZ=5–90. In addition to these results the half life of the 514 keV state of⁸⁵Rb and the branching ratios and the positron rate of the⁸⁸Y-decay have been measured with the same techniques. The data obtained partly disagree from measurements of other authors.     

Das Kernquadrupolelement des Os189

The hyperfine structure of 11 Os I-lines in the violet and ultraviolet spectral range was investigated by a digital recording Fabry Perot spectrometer. An enriched sample of Os¹⁸⁹ was used in the hollow cathode light source. The recorded structures were analyzed on a computer. The quadrupole coupling constants of the states 5d ⁶6s ^{2 5} D ₂,⁵ D ₃,⁵ D ₄ and 5d ⁷6s ⁵ F ₅ or linear combinations of these coupling constants were deduced from the measurements. With these results the nuclear quadrupole moment of Os¹⁸⁹ was determined to beQ(Os¹⁸⁹)=(0.91 ± 0.10) · 10^?24 cm². This was done using the eigenfunctions ofGluck, Bordarier, Bauche andVan Kleef, which have been calculated for intermediate coupling considering configuration interaction.     

Measurement of K-electron capture probabilities to the levels of185Re following the EC decay of185Os

K to total capture ratios have been measured explicitly for the first time from the decay of¹⁸⁵Os to 880, 874, 717 and 646 keV levels in¹⁸⁵Re using the technique of gamma-KX-ray summing in a single intrinsic Ge detector. The results agree with the theoretical values.GPSS is grateful to the CSIR, Goverment of India, for the award of an NET Senior Research Fellowship.     

Die relative Isotopenlage des Os186

Using three different samples of Os¹⁹², Os¹⁹⁰ and Os¹⁸⁶ enriched to 98.68%, 95.46%, and 61.27%, respectively, the isotopic shiftsΔν(Os¹⁹²?Os¹⁹⁰) andΔν(Os¹⁹²?Os¹⁸⁶) have been measured in four Os I-lines with a recording Fabry-Perot spectrometer. The relative isotopic position of Os¹⁸⁶ has been found to be

$$\frac{{\Delta \nu (Os^{192} - Os^{186} )}}{{\Delta \nu (Os^{192} - Os^{190} )}} = 3.52 \pm 0.03.$$     

Untersuchung derK-Strahlung beim Elektroneneinfang des Ge71 mit einem Diffraktionsspektrometer mit gebogenem Kristall

The intensity of satellites in the Gallium-x-rays emitted inK-capture of Ge⁷¹ has been measured and found to be (1,3±0,5)×10^?4 perK-capture. A curved-crystal X-ray spectrometer with a radius of curvature of 27 cm was used for the measurement. The satellites are found to be due to double ionisation ofK-shell accompanyingK-capture as described by the theory ofPrimakoff andPorter. The theoretically calculated intensity of X-ray satellites emitted due to double ionisation ofK-shell — (0,9)×10^?4 perK-capture — is in fair agreement with experiment.