Measurement of UNILAC and SIS18 proton performance

On July 16th 2016 the UNILAC and SIS18 proton performance has been measured. Due to scheduled maintenance works of the UNILAC's rf-system, the post-stripper energy was restricted to 5.9~MeV and accordingly the beam quality suffered considerably from the interruption of the periodic focusing system. This limitation will not be any longer in future beam times. Six single-gap resonators were used for acceleration to 10.7~MeV. After an optimization of the multi-turn injection $\pmb{1.2\cdot10^{11}}$ protons were extracted form the SIS18

Straight injection of an intense uranium beam into the GSI High Current RFQ

A dedicated high current uranium ion source and LEBT will be built at the GSI High Current Injector (HSI), to fulfil the intensity requirements for FAIR (Facility forAntiproton and Ion Research at Darmstadt). This new injection line will be integrated into the existingcomplex which already comprises two branches. The new LEBT is designed as a straight injection linewithout dipole magnet, i.e. without dispersive charge stateseparation. All uranium charge states, coming from theion source, are transported to the heavy ion high current GSI-HSI-RFQ. Only the design charge state U4+ is accelerated to the final RFQ energy. The new LEBT design is based on beam emittance and current measurements behind the existing ion source. Beam dynamics simulations have been performed with thecodes TRACE-3D (envelopes), DYNAMION,BEAMPATH and TRACK (multiparticle). The recentlayout of the LEBT, as well as the results of beam dynamics studies are presented

Time-dependent conduction current in lithium niobate crystals with charged domain walls

We present the experimental study of the increase and decrease of the abnormal conduction current appeared during polarization reversal at elevated temperatures (120-250 °C) in stoichiometric and MgO doped lithium niobate single crystals. It is shown that the conduction current is caused by existence of the through charged domain walls. The time dependence of the conduction current has been measured in low electric field immediately after partial switching. The maximal value of the conduction current in crystal with through charged domain walls is of 4-5 orders of magnitude higher than in initial single domain state. The activation energy is 1.1 eV. © 2013 AIP Publishing LLC

Complexes of non-lacunary Keggin- and Dawson-type polyoxometalates with Pb(ii): formation of 1D coordination polymers with different bonding modes

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.A new coordination polymer based on Keggin-type [SiW12O40]4- and Pb2+ ions, {Pb2(μ2-DMF)2(DMF)8(SiW12O40)} (1a), was prepared by a reaction between H4[SiW12O40] and Pb(NO3)2 in N,N-dimethylformamide (DMF). Varying the crystallization conditions, a complex with a slightly different coordination mode of the {Pb2} unit and solvate composition, {Pb2(μ2-DMF)2(DMF)8(SiW12O40)}·DMF (1b), can be obtained. The complex containing Well-Dawson polyoxoanions, {(Pb(μ2-DMF)3(DMF)6)(Pb(DMF)5)(P2W18O62)}·0.5DMF·1.3H2O (2), was prepared by a similar strategy

Polymeric hybrid iodoplumbates and iodobismuthates containing mono- and bisalkylated derivatives of 1,2-bis(4-pyridyl)ethylene: Structural and optical features

© 2017 Elsevier B.V.Reactions of PbI2 with N-alkylated derivatives of 1,2-bis(4-pyridyl)ethylene (bpen) MeBpenI and Me2BpenI2 result in 1D-polymeric complexes [{Pb(MeBpen)I3}] (1) and (Me2bpen)[{PbI3}]2 (2). For both compounds, band gap values were determinated experimentally; 1 demonstrates weak red luminescence. Binuclear hybrid iodobismuthate [Bi2(MeBpen)2I8] (3) was obtained by the similar scheme using BiI3 instead of PbI2