A study of the de-excitation of primary fission fragments from the neutron-induced fission of 235U

Two separate three-dimensional experiments have been performed in which the energies of coincident fragment pairs and γ-rays or internal conversion electrons, emitted within ≈ 1.6 nsec of the thermal-neutron-induced fission of ²³⁵U, were recorded event by event. The fragment kinetic energies were used for mass identification. The self-consistency of the values of electron energy, γ-ray energy and fragment charge, and its agreement with X-ray selection data, were used to identify the atomic numbers of the fragments. The analysis of the γ-ray and conversion electron spectra resulted in the assignment of many transitions to new isotopes as well as improvement in or confirmation of many assignments from the ²⁵²Cf spontaneous fission data. Limited information on the multipolarities of the transitions in even nuclei is presented. The relative yield of electrons per fragment indicates softness to deformation in the mass region 100–110. Data are presented supporting the assignment of a 193 keV transition as the 2⁺ → 0⁺ transition in ⁹⁸Sr. An examination of the 2⁺ → 0⁺ level systematics of neighbouring even nuclei suggests a transition from vibrational to rotational behaviour in the light fragments between neutron numbers 58 and 60.     

New calibration method for solid sampling Zeeman atomic absorption spectrometry (SS-ZAAS) for cadmium

Summary Calibration of solid sampling Zeeman AAS for cadmium was investigated. A series of certified reference materials was analysed using a CRM with a different composition as standard. For routine applications this yielded satisfactory results. A method of calibration was then applied involving addition of standard solution to lyophilized samples, followed by lyophilization and homogenization. Using an iteration procedure results were obtained which no longer depend on certified reference materials. The method was applied to the analysis of a testbatch of codfish powder prepared at CBNM. Finally, the spiked fish standards obtained in this way were also used to analyse other certified reference materials.     

Der Polarisationsgrad der Neutronen aus der ReaktionD(d,n)3He fürE d=80 bis 140keV

Zeitschrift für Physik A Hadrons and nuclei - The polarization of neutrons from thed-d-reaction was investigated in the energy regionE d=80 to 140keV at an angle ofΘ 1=50°lab. Using...