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A precise transmission measurement of the cross sections of Bismuth, Lead, Silicone and Carbon for 130 eV neutrons (Co-resonance) has been carried out. A new resonance method has been applied, using epithermal reactor neutrons, which have been scattered twice from Co-foils. - We obtained the total 130 eV cross sections: Bi: 9,182 ± 0,007 b, Pb: 11,295 ± 0,009 b, Si:2,0442 ± 0,0018 b, C: 4,746 ± 0,007 b. From these results the coherent nuclear scattering lengths (bound), Bi: 8,646 ± 0,005 fm, Pb : 9,524 ± 0,004 fm, C: 6,660 ± 0,006 fm, have been calculated, under consideration of various corrections (absorption, Schwinger-scattering, Incoherence, Neutron-Electron-Interaction, energy-dependence of nuclear-scattering).

Gamma radiation from the capture of neutrons in natural Se and in enriched 76Se and 80Se has been studied with different Ge (Li)-detectors, with a Ge(Li)-NaJ pair spectrometer and with a Ge (Li) -Ge (Li) two-paramater γ-γ coincidence system. These measurements resulted in a considerable improvement of the level schemes of 77Se, 78Se and 81Se. The 81Se and the 107Ag level schemes are compared, and the applicability of phonon-particle coupling to low-lying states of 81Se is discussed. In the case of 77Se, some properties may be possibly better described by the Nilsson model. It is rather clear, however, that both models can only be regarded as limited approximations and that more refined models are required for Se nuclei. The well-known, unusually small isomeric cross section ratio of 81Se, and the weak population of p-single-quasiparticle states by primary transitions from the capture state 80Se + n, which shows up in our measurements, may be understood by assuming a capture state containing a doorway state with a simple collective excitation.

Es wurde eine systematische Untersuchung der (n,n'γ) -Querschnitte für 14 MeV-Neutronen an gg-Kernen im Massenbereich A = 46 - 88 durchgeführt und die Querschnitte für die Anregung des ersten 2+-Niveaus für 19 Kerne im genannten Massenbereich wurden gemessen. Die Ergebnisse können durch das statistische Modell der Kernreaktionen befriedigend erklärt werden.