4,875 research outputs found

    Multi-Gigabit Wireless data transfer at 60 GHz

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    In this paper we describe the status of the first prototype of the 60 GHz wireless Multi-gigabit data transfer topology currently under development at University of Heidelberg using IBM 130 nm SiGe HBT BiCMOS technology. The 60 GHz band is very suitable for high data rate and short distance applications as for example needed in the HEP experments. The wireless transceiver consist of a transmitter and a receiver. The transmitter includes an On-Off Keying (OOK) modulator, an Local Oscillator (LO), a Power Amplifier (PA) and a BandPass Filter (BPF). The receiver part is composed of a BandPass- Filter (BPF), a Low Noise Amplifier (LNA), a double balanced down-convert Gilbert mixer, a Local Oscillator (LO), then a BPF to remove the mixer introduced noise, an Intermediate Amplifier (IF), an On-Off Keying demodulator and a limiting amplifier. The first prototype would be able to handle a data-rate of about 3.5 Gbps over a link distance of 1 m. The first simulations of the LNA show that a Noise Figure (NF) of 5 dB, a power gain of 21 dB at 60 GHz with a 3 dB bandwidth of more than 20 GHz with a power consumption 11 mW are achieved. Simulations of the PA show an output referred compression point P1dB of 19.7 dB at 60 GHz.Comment: Proceedings of the WIT201

    Interferometric Observations of the Nuclear Region of Arp220 at Submillimeter Wavelengths

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    We report the first submillimeter interferometric observations of an ultraluminous infrared galaxy. We observed Arp220 in the CO J=3-2 line and 342GHz continuum with the single baseline CSO-JCMT interferometer consisting of the Caltech Submillimeter Observatory (CSO) and the James Clerk Maxwell Telescope (JCMT). Models were fit to the measured visibilities to constrain the structure of the source. The morphologies of the CO J=3-2 line and 342GHz continuum emission are similar to those seen in published maps at 230 and 110GHz. We clearly detect a binary source separated by about 1 arcsec in the east-west direction in the 342GHz continuum. The CO J=3-2 visibility amplitudes, however, indicate a more complicated structure, with evidence for a compact binary at some velocities and rather more extended structure at others. Less than 30% of the total CO J=3-2 emission is detected by the interferometer, which implies the presence of significant quantities of extended gas. We also obtained single-dish CO J=2-1, CO J=3-2 and HCN J=4-3 spectra. The HCN J=4-3 spectrum, unlike the CO spectra, is dominated by a single redshifted peak. The HCN J=4-3/CO J=3-2, HCN J=4-3/HCN J=1-0 and CO J=3-2/2-1 line ratios are larger in the redshifted (eastern) source, which suggests that the two sources may have different physical conditions. This result might be explained by the presence of an intense starburst that has begun to deplete or disperse the densest gas in the western source, while the eastern source harbors undispersed high density gas.Comment: 17 pages, 9 figures, 4 Tables. accepted by Ap

    Wafer test of the LHCb Outer Tracker TDC-Chip

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    The OTIS-TDC is the front end readout chip for the LHCb Outer Tracker. It is designed to measure drift times with a resolution better than 1 ns. As the chip will be directly mounted to its board, the test have to be performed on the wafer itself. As the testing period for 7 000 chips was only three weeks, many test routines have been implemented on a FPGA. Each chip is subjected to detailed probe testing to ensure the full functionality as well as a good performance. Overall 47 wafer have been tested. From the chips passing the test 2 000 have been used in the Outer Tracker front end electronic

    MuPix7 - A fast monolithic HV-CMOS pixel chip for Mu3e

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    The MuPix7 chip is a monolithic HV-CMOS pixel chip, thinned down to 50 \mu m. It provides continuous self-triggered, non-shuttered readout at rates up to 30 Mhits/chip of 3x3 mm^2 active area and a pixel size of 103x80 \mu m^2. The hit efficiency depends on the chosen working point. Settings with a power consumption of 300 mW/cm^2 allow for a hit efficiency >99.5%. A time resolution of 14.2 ns (Gaussian sigma) is achieved. Latest results from 2016 test beam campaigns are shown.Comment: Proceedingsfor the PIXEL2016 conference, submitted to JINST A dangling reference has been removed from this version, no other change

    Research Proposal for an Experiment to Search for the Decay {\mu} -> eee

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    We propose an experiment (Mu3e) to search for the lepton flavour violating decay mu+ -> e+e-e+. We aim for an ultimate sensitivity of one in 10^16 mu-decays, four orders of magnitude better than previous searches. This sensitivity is made possible by exploiting modern silicon pixel detectors providing high spatial resolution and hodoscopes using scintillating fibres and tiles providing precise timing information at high particle rates.Comment: Research proposal submitted to the Paul Scherrer Institute Research Committee for Particle Physics at the Ring Cyclotron, 104 page

    The {\eta}'-carbon potential at low meson momenta

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    The production of η\eta^\prime mesons in coincidence with forward-going protons has been studied in photon-induced reactions on 12^{12}C and on a liquid hydrogen (LH2_2) target for incoming photon energies of 1.3-2.6 GeV at the electron accelerator ELSA. The η\eta^\prime mesons have been identified via the ηπ0π0η6γ\eta^\prime\rightarrow \pi^0 \pi^0\eta \rightarrow 6 \gamma decay registered with the CBELSA/TAPS detector system. Coincident protons have been identified in the MiniTAPS BaF2_2 array at polar angles of 2θp112^{\circ} \le \theta _{p} \le 11^{\circ}. Under these kinematic constraints the η\eta^\prime mesons are produced with relatively low kinetic energy (\approx 150 MeV) since the coincident protons take over most of the momentum of the incident-photon beam. For the C-target this allows the determination of the real part of the η\eta^\prime-carbon potential at low meson momenta by comparing with collision model calculations of the η\eta^\prime kinetic energy distribution and excitation function. Fitting the latter data for η\eta^\prime mesons going backwards in the center-of-mass system yields a potential depth of V = -(44 ±\pm 16(stat)±\pm15(syst)) MeV, consistent with earlier determinations of the potential depth in inclusive measurements for average η\eta^\prime momenta of \approx 1.1 GeV/cc. Within the experimental uncertainties, there is no indication of a momentum dependence of the η\eta^\prime-carbon potential. The LH2_2 data, taken as a reference to check the data analysis and the model calculations, provide differential and integral cross sections in good agreement with previous results for η\eta^\prime photoproduction off the free proton.Comment: 9 pages, 13 figures. arXiv admin note: text overlap with arXiv:1608.0607

    The Herschel Comprehensive (U)LIRG Emission Survey (HerCULES): CO Ladders, fine structure lines, and neutral gas cooling

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    (Ultra) Luminous Infrared Galaxies ((U)LIRGs) are objects characterized by their extreme infrared (8-1000 μ\mum) luminosities (LLIRG>1011L_{LIRG}>10^{11} L_\odot and LULIRG>1012L_{ULIRG}>10^{12} L_\odot). The Herschel Comprehensive ULIRG Emission Survey (HerCULES; PI van der Werf) presents a representative flux-limited sample of 29 (U)LIRGs that spans the full luminosity range of these objects (1011L1013^{11}\leq L_\odot \geq10^{13}). With the \emph{Herschel Space Observatory}, we observe [CII] 157 μ\mum, [OI] 63 μ\mum, and [OI] 145 μ\mum line emission with PACS, CO J=4-3 through J=13-12, [CI] 370 μ\mum, and [CI] 609 μ\mum with SPIRE, and low-J CO transitions with ground-based telescopes. The CO ladders of the sample are separated into three classes based on their excitation level. In 13 of the galaxies, the [OI] 63 μ\mum emission line is self absorbed. Comparing the CO excitation to the IRAS 60/100 μ\mum ratio and to far infrared luminosity, we find that the CO excitation is more correlated to the far infrared colors. We present cooling budgets for the galaxies and find fine-structure line flux deficits in the [CII], [SiII], [OI], and [CI] lines in the objects with the highest far IR fluxes, but do not observe this for CO 4Jupp134\leq J_{upp}\leq13. In order to study the heating of the molecular gas, we present a combination of three diagnostic quantities to help determine the dominant heating source. Using the CO excitation, the CO J=1-0 linewidth, and the AGN contribution, we conclude that galaxies with large CO linewidths always have high-excitation CO ladders, and often low AGN contributions, suggesting that mechanical heating is important

    SMA CO(J=6-5) and 435 micron interferometric imaging of the nuclear region of Arp 220

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    We have used the Submillimeter Array (SMA) to make the first interferometric observations (beam size ~1") of the 12CO J=6-5 line and 435 micron (690 GHz) continuum emission toward the central region of the nearby ULIRG Arp 220. These observations resolve the eastern and western nuclei from each other, in both the molecular line and dust continuum emission. At 435 micron, the peak intensity of the western nucleus is stronger than the eastern nucleus, and the difference in peak intensities is less than at longer wavelengths. Fitting a simple model to the dust emission observed between 1.3 mm and 435 micron suggests that dust emissivity power law index in the western nucleus is near unity and steeper in the eastern nucleus, about 2, and that the dust emission is optically thick at the shorter wavelength. Comparison with single dish measurements indicate that the interferometer observations are missing ~60% of the dust emission, most likely from a spatially extended component to which these observations are not sensitive. The 12CO J=6-5 line observations clearly resolve kinematically the two nuclei. The distribution and kinematics of the 12CO J=6-5 line appear to be very similar to lower J CO lies observed at similar resolution. Analysis of multiple 12CO line intensities indicates that the molecular gas in both nuclei have similar excitation conditions, although the western nucleus is warmer and denser. The excitation conditions are similar to those found in other extreme environments, including M82, Mrk 231, and BR 1202-0725. Simultaneous lower resolution observations of the 12CO, 13CO, and C18O J=2-1 lines show that the 13CO and C18O lines have similar intensities, which suggests that both of these lines are optically thick, or possibly that extreme high mass star formation has produced in an overabundance of C18O.Comment: 13 pages (emulateapj), 10 figures, Accepted for publication in Ap
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