A 16-channel Digital TDC Chip with internal buffering and selective readout for the DIRC Cherenkov counter of the BABAR experiment

A 16-channel digital TDC chip has been built for the DIRC Cherenkov counter of the BaBar experiment at the SLAC B-factory (Stanford, USA). The binning is 0.5 ns, the conversion time 32 ns and the full-scale 32 mus. The data driven architecture integrates channel buffering and selective readout of data falling within a programmable time window. The time measuring scale is constantly locked to the phase of the (external) clock. The linearity is better than 80 ps rms. The dead time loss is less than 0.1% for incoherent random input at a rate of 100 khz on each channel. At such a rate the power dissipation is less than 100 mw. The die size is 36 mm2.Comment: Latex, 18 pages, 13 figures (14 .eps files), submitted to NIM

Electrical Characterization of a Thin Edgeless N-on-p Planar Pixel Sensors For ATLAS Upgrades

In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. Because of its radiation hardness and cost effectiveness, the n-on-p silicon technology is a promising candidate for a large area pixel detector. The paper reports on the joint development, by LPNHE and FBK of novel n-on-p edgeless planar pixel sensors, making use of the active trench concept for the reduction of the dead area at the periphery of the device. After discussing the sensor technology, and presenting some sensors' simulation results, a complete overview of the electrical characterization of the produced devices will be given.Comment: 9 pages, 9 figures, to appear in the proceedings of the 15th International Workshops on Radiation Imaging Detector

Novel Silicon n-on-p Edgeless Planar Pixel Sensors for the ATLAS upgrade

In view of the LHC upgrade phases towards HL-LHC, the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. The n-on-p silicon technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors. We report on the development of novel n-in-p edgeless planar pixel sensors fabricated at FBK (Trento, Italy), making use of the "active edge" concept for the reduction of the dead area at the periphery of the device. After discussing the sensor technology and fabrication process, we present device simulations (pre- and post-irradiation) performed for different sensor configurations. First preliminary results obtained with the test-structures of the production are shown.Comment: 6 pages, 5 figures, to appear in the proceedings of the 9th International Conference on Radiation Effects on Semiconductor Materials Detectors and Device

Development of Edgeless n-on-p Planar Pixel Sensors for future ATLAS Upgrades

The development of n-on-p "edgeless" planar pixel sensors being fabricated at FBK (Trento, Italy), aimed at the upgrade of the ATLAS Inner Detector for the High Luminosity phase of the Large Hadron Collider (HL-LHC), is reported. A characterizing feature of the devices is the reduced dead area at the edge, achieved by adopting the "active edge" technology, based on a deep etched trench, suitably doped to make an ohmic contact to the substrate. The project is presented, along with the active edge process, the sensor design for this first n-on-p production and a selection of simulation results, including the expected charge collection efficiency after radiation fluence of $1 \times 10^{15} {\rm n_{eq}}/{\rm cm}^2$ comparable to those expected at HL-LHC (about ten years of running, with an integrated luminosity of 3000 fb$^{-1}$) for the outer pixel layers. We show that, after irradiation and at a bias voltage of 500 V, more than 50% of the signal should be collected in the edge region; this confirms the validity of the active edge approach.Comment: 20 pages, 9 figures, submitted to Nucl. Instr. and Meth.

Performance of Irradiated Thin Edgeless N-on-P Planar Pixel Sensors for ATLAS Upgrades

In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. Because of its radiation hardness and cost effectiveness, the n-on-p silicon technology is a promising candidate for a large area pixel detector. The paper reports on the joint development, by LPNHE and FBK of novel n-on-p edgeless planar pixel sensors, making use of the active trench concept for the reduction of the dead area at the periphery of the device. After discussing the sensor technology, a complete overview of the electrical characterization of several irradiated samples will be discussed. Some comments about detector modules being assembled will be made and eventually some plans will be outlined.Comment: 6 pages, 13 figures, to appear in the proceedings of the 2013 Nuclear Science Symposium and Medical Imaging Conference. arXiv admin note: text overlap with arXiv:1311.162

In situ relationships between microbiota and potential pathobiota in Arabidopsis thaliana.

A current challenge in microbial pathogenesis is to identify biological control agents that may prevent and/or limit host invasion by microbial pathogens. In natura, hosts are often infected by multiple pathogens. However, most of the current studies have been performed under laboratory controlled conditions and by taking into account the interaction between a single commensal species and a single pathogenic species. The next step is therefore to explore the relationships between host-microbial communities (microbiota) and microbial members with potential pathogenic behavior (pathobiota) in a realistic ecological context. In the present study, we investigated such relationships within root-associated and leaf-associated bacterial communities of 163 ecologically contrasted Arabidopsis thaliana populations sampled across two seasons in southwest of France. In agreement with the theory of the invasion paradox, we observed a significant humped-back relationship between microbiota and pathobiota α-diversity that was robust between both seasons and plant organs. In most populations, we also observed a strong dynamics of microbiota composition between seasons. Accordingly, the potential pathobiota composition was explained by combinations of season-specific microbiota operational taxonomic units. This result suggests that the potential biomarkers controlling pathogen\u27s invasion are highly dynamic