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The new FAIR facility at GSI will include a research program with antiproton beams besides a largely extended activity with heavy ion beams. The requested antiproton production rate of 7•10 10 has to be achieved with a linac-synchrotron SIS12-SIS100 accelerator configuration. Therefore GSI needs now a high intensity, pulsed proton linac as an independent new linac, additionally to the heavy ion linac injector UNILAC. A novel compact p linac for an operating frequency of 352 MHz has been designed. It is based on an RFQ of the 4-rod type or alternatively of the 4window type followed by a CrossBar H-type (CH)-DTL ranging from 3 MeV up to 70 MeV. At an aperture diameter of 20 mm these structures will reach effective shunt impedances between 100 MΩ/m and 40 MΩ/m (high energy end). 11 independently phased cavities with focusing quadrupole triplets in the intertank sections will provide 67 MV effective voltage gain within a total length of 21 m. Beam dynamics studies are promising. Depending on the beam current, the needed transverse emittance is defined by the multiturn injection scheme into the horizontal phase space of SIS12. It is aimed to fill up to 7•10 12 protons into SIS12 within 25µs at linac currents around 70 mA and at a normalized horizontal beam emittance of 3 µm. The energy spread has to be kept within ± 1•10-3. This design was also guided by available 352 MHz klystrons with peak rf power levels slightly above 1 MW.

IntroductionTrees interact with fungi in mutualistic, saprotrophic, and pathogenic relationships. With their extensive aboveground and belowground structures, trees provide diverse habitats for fungi. Thus, tree species identity is an important driver of fungal community composition in forests.MethodsHere we investigate how forest habitat (bark surface vs. soil) and tree species identity (deciduous vs. coniferous) affect fungal communities in two Central European forests. We assess differences and interactions between fungal communities associated with bark surfaces and soil, in forest plots dominated either by Fagus sylvatica, Picea abies, or Pinus sylvestris in two study regions in southwestern and northeastern Germany.ResultsITS metabarcoding yielded 3,357 fungal amplicon sequence variants (ASVs) in the northern and 6,088 in the southern region. Overall, soil communities were 4.7 times more diverse than bark communities. Habitat type explained 48–69% of the variation in alpha diversity, while tree species identity explained >1–3%. NMDS ordinations showed that habitat type and host tree species structured the fungal communities. Overall, few fungal taxa were shared between habitats, or between tree species, but the shared taxa were highly abundant. Network analyses, based on co-occurrence patterns, indicate that aboveground and belowground communities form distinct subnetworks.DiscussionOur study suggests that habitat (bark versus soil) and tree species identity are important factors structuring fungal communities in temperate European forests. The aboveground (bark-associated) fungal community is currently poorly known, including a high proportion of reads assigned to “unknown Ascomycota” or “unknown Dothideomycetes.” The role of bark as a habitat and reservoir of unique fungal diversity in forests has been underestimated.

Previously it has been shown that the resistivity of Bi0.4Ca0.6MnO3 epitaxial thin films on oxide substrates decreases significantly upon illumination with visible light. The resistivity decrease is observed over a wide temperature range and is understood as arising due to the destruction of charge ordering. The light responsivity makes Bi0.4Ca0.6MnO3 thin films attractive for photonic and optoelectronic device applications. In this paper, we report the heteroepitaxy of Bi0.4Ca0.6MnO3 thin films on (001) Si which is relevant for the potential integration of the optoelectronic/photonic functionality of Bi0.4Ca0.6MnO3 with semiconductor electronics. As in the case of other perovskite oxides, heteroepitaxy of Bi0.4Ca0.6MnO3 on Si requires the use of buffer layers to circumvent the problems associated with the presence of an amorphous native silicon dioxide layer and the reactivity of perovskite oxides with Si at high temperatures. We demonstrate that high quality epitaxial thin films of Bi0.4Ca0.6MnO3 can be grown via pulse laser deposition on Si that has been prebuffered with a SrTiO3 layer via a Motorola molecular beam epitaxy process. The magnitude and dynamics of the photoresponse in these films is comparable to that of Bi0.4Ca0.6MnO3 films on oxide substrates.