MAFF — The Munich accelerator for fission fragments

At the new high flux reactor FRM-II in Munich the accelerator MAFF (Munich accelerator for fission fragments) is under design. In the high neutron flux of 10¹⁴ n/cm² s up to 10¹⁴ neutron-rich fission fragments per second are produced in the 1 g U-235 target. Ions with an energy of 30 keV are extracted from the ion source. In the mass separator two isotopes can be selected. One of the beams is used for low energy experiments, the other one is injected into an ECRIS (or EBIS) for charge breeding to a q/A≥0.16. A gas filled RFQ cooler is used for emittance improvement. The subsequent LINAC delivers beams with an energy ranging from 3.7 MeV/u to 5.9 MeV/u. New IH structures are being developed at the Munich tandem laboratory. A small storage ring is planned in a further stage to recycle the fission fragments. A thin target foil can be placed into this ring, e.g., for synthesis of super-heavy elements. The through-going beam tube has been installed in the heavy water tank of the reactor. Tests of the target ion source in a special oven to test long term stability and safety tests were in progress.     

Synthesis of photosensitizer pairs containing Ru(bpy)3 2+ and an electron acceptor (viologen) linked by a hydrocarbon chain

Conclusions Two Ru(bpy)₃ ²⁺-viologen complexes, in which the components are linked by a hydrocarbon chain, were synthesized and characterized by PMR, visible, and UV spectrophotometry.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 700–703, March, 1989.     

Formation and stability of Gd, Y, Yb and Lu disilicates and their solid solutions

The synthesis and the phase stability regions of the disilicates of Y, Lu, Yb and Gd have been investigated at temperatures between 1300 and 1600 °C. The mean ionic radius of the rare-earth element ion including Y turns out to be the key parameter to govern the stabilities of polymorph types of both pure disilicates and their solid solutions. Both are predicted correctly by the phase stability diagram of Felsche [1] [J. Felsche, Struct. Bond. 13 (1973) 99-197]. Furthermore, it correlates with the reactivity, with increasing radius a faster reaction is observed at a given temperature. A fast reactivity is assumed to create difficulties in the densification of disilicates with ionic radius exceeding ∼0.88 Å. In the reaction from oxide powders monosilicates are formed in a first step. Disilicates are formed from those initially in the form of low-temperature modifications, which transform in a sequence to high-temperature modifications.     

Lasing of a DCM dye layer in carbazole-based films

We have studied the spectral and lasing properties of 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) in polyepoxypropylcarbazole (PEPK), polybutylcarbazole (PBK), and polyvinylcarbazole (PVK) films when excited by emission from a XeCl laser (λ = 308 nm) and the second harmonic of a YAGNd laser (λ = 532 nm). Stimulated emission was excited without an external cavity in the traveling wave mode in films of thickness 0.5–0.8 μm, obtained by the centrifuging method. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 177–181, March–April, 2006.     

Isomeric states in180Os

Two new isomers have been observed in¹⁸⁰Os. A high-K isomer withI, K ≧20 and a half-life ofT _1/2=12+4 ns have been established. It deexcites via two transitions into the 18⁺ level of the yrare band indicating an unusually smallK-hindrance factor. Evidence for an isomer withI, K>16 and a half-life ofT _1/2=41±10 ns was found. A half-life of 17±3 ns was measured for the previously known 7^? state at 1862 keV. The decay scheme of the previously known 7^? isomer at 1928 keV has been extended and a revised version is presented.