Asimakopoulou E-M, Madesis I, Dimitriou A, Zouros TJM, Mertzimekis TJ, Lagoyannis A, Axiotis M.
Incorporation of an Ion Post Stripper for the APAPES Experimental Setup. In: Hellenic Nuclear Physics Society; 2014.
Lagaki V, Kouvaris E, Mertzimekis TJ.
A new γ-spectroscopy station at the University of Athens. In: Hellenic Nuclear Physics Society; 2014.
Tzifas IT, Godelitsas A, Magganas A, Androulakaki E, Eleftheriou G, Mertzimekis TJ, Perraki M.
Uranium-bearing phosphatized limestones of \{NW\} Greece. J. Geochem. Explor. 2014;143:62 – 73.
AbstractAbstract Sedimentary Mesozoic rocks from \{NW\} Greece (Epirus region), and particularly laminated phosphatized limestones, bedded chert-rich limestones and brecciated phosphatized limestones, were examined for their actinide content. Gamma-ray measurements using a \{HPGe\} detector showed that the above geological materials exhibit high radioactivity, mainly attributed to the 238U-series. The 238U content (up to 7700 Bq/kg) was determined by the 1001 keV photopeak of 234mPa, the 238U daughter. Bulk geochemical analyses using ICP-OES/MS showed variable U concentrations with a notable value of 648 ppm in the case of dark organic-rich material hosted into the brecciated phosphatized limestones. Relatively high concentrations of Cd, probably related to apatite, were also revealed. On the other hand, the rock is geochemically depleted in \{LILE\} (e.g. Cs, Rb, K), as well as in As, Sb and Se in contrast to “average phosphorite”. Powder-XRD combined with optical microscopy, SEM–EDS and \{FTIR\} confirmed abundant apatite, besides calcite, as well as organic compounds (organic matter/O.M.) which should be associated to the high U content. According to Th/Sc vs. Zr/Sc discrimination diagrams the organic-rich part of the U-bearing phosphatised limestones exhibits a mafic trend, in contrast to the rest of the studied rocks lying close to typical pelagic sediments. However, Eu/Eu* vs. Ce/Ce* diagrams, in combination with SEM–EDS, indicated that the organic-rich part is a typical sedimentary material whereas the organic-poor (and also U-poor) part of the rock is secondary calcite related to surface waters. As far as we know, the studied rocks from \{NW\} Greece are classified as among the richest U-bearing phosphatized limestones and/or sedimentary phosphorites in the world.
Diriken J, Patronis N, Andreyev AN, Antalic S, Bildstein V, Blazhev A, Darby IG, Witte DH, Eberth J, Elseviers J, et al. Study of the deformation-driving orbital in $^{67}_{28}$Ni$_{39}$ using one-neutron transfer reactions. Phys. Lett. B. 2014;736:533–538.
AbstractAbstract The νg$_{9/2}$, d$_{5/2}$, s$_{1/2}$ orbitals are assumed to be responsible for the swift onset of collectivity observed in the region below $^{68}$Ni. Especially the single-particle energies and strengths of these orbitals are of importance. We studied such properties in the nearby $^{67}$Ni nucleus, by performing a (d,p)-experiment in inverse kinematics employing a post-accelerated radioactive ion beam (RIB) at the REX-ISOLDE facility. The experiment was performed at an energy of 2.95 MeV/u using a combination of the T-REX particle detectors, the Miniball γ-detection array and a newly-developed delayed-correlation technique as to investigate μs-isomers. Angular distributions of the ground state and multiple excited states in $^{67}$Ni were obtained and compared with DWBA cross-section calculations, leading to the identification of positive-parity states with substantial νg$_{9/2}$ (1007 keV) and νd$_{5/2}$ (2207 keV and 3277 keV) single-particle strengths up to an excitation energy of 5.8 MeV. 50% of the νd$_{5/2}$ single-particle strength relative to the νg$_{9/2}-orbital is concentrated in and shared between the first two observed 5/2^{+} levels. A comparison with extended Shell Model calculations and equivalent ($^3$He, d) studies in the region around $^{90}_{40}$Zr$_{50}$ highlights similarities for the strength of the negative-parity pf and positive-parity g$_{9/2}$ state, but differences are observed for the d$_{5/2} single-particle strength.