18307118
Design and Verification of an FPGA-based Bit Error Rate Tester
Abstract Bit error rate (BER) is the principle measure of performance of a data transmission link. With the integration of high-speed transceivers inside a field programmable gate array (FPGA), the BER testing can now be handled by transceiver-enabled FPGA hardware. This provides a cheaper alternative to dedicated table-top equipment and offers the flexibility of test customization and data analysis. This paper presents a BER tester implementation based on the Altera Stratix II GX and IV GT development boards. The architecture of the tester is described. Lab test results and field test data analysis are discussed. The Stratix II GX tester operates at up to 5 Gbps and the Stratix IV GT tester operates at up to 10 Gbps, both in 4 duplex channels. The tester deploys a pseudo random bit sequence (PRBS) generator and detector, a transceiver controller, and an error logger. It also includes a computer interface for data acquisition and user configuration. The tester's functionality was validated and its performance characterized in a point-to-point serial optical link setup. BER vs. optical receiver sensitivity was measured to emulate stressed link conditions. The Stratix II GX tester was also used in a proton test on a custom designed serializer chip to record and analyse radiation-induced errors.
110567078
ASIC developments for high speed serial data transmission in particle physics experiments
Abstract We report R&D results on two integrated circuit designs: a 5 Gbps 16:1 serializer and a 5 GHz LC phase-locked-loop (PLL). The prototypes were fabricated with a commercial thin-film silicon-on-sapphire 0.25 μm CMOS technology. Both the serializer and the PLL have been evaluated to meet design goals and tested against operation conditions in the environment of a particle physics detector front-end for the proposed HL-LHC upgrade.
119904892
Radiation hardness of optoelectronic components for the optical readout of the ATLAS inner detector
Abstract Optical links are used for data transmission of the ATLAS inner detector in a radiation hazard environment at the Large Hadron Collider (LHC). The radiation tolerance is studied for the opto-electronics of GaAs VCSEL and epitaxial Si PIN with 30 and 70 MeV protons at CYRIC. High speed Si and GaAs PIN photo-diodes are also investigated for upgrade to super-LHC. The annealing of GaAs VCSEL by charge injection is characterized. The GaAs devices show approximately linear degradations to fluence. The dependence on proton energy is compared to the Non-Ionizing Energy Loss calculations.
122173376
Preliminary results from the ROC-Europe transition radiation experiment with a multichannel superheated superconducting grain detector
Abstract A compact multichannel Superheated Superconducting Grain detector (SSG) has been irradiated by the T9 beam (mostly composed by high energy electrons) of the SPS machine at CERN. The SSG detector consists of a set of cylindrical suspensions of tin grains with various filling factors, all of them parallel to the beam line and kept in an 3 He – 4 He single-dilution chamber. Transitions to the normal state of the grains were detected with a GaAs high electron mobility field effect transistor (HEMFET) preamplifier cooled to 4.2 K. We present a preliminary analysis of the results obtained with beam energies from 1 to 14 GeV and a 33–37 μm size distribution of the grains.
122397846
Measurement of diboson production with the ATLAS detector
ATLAS measurements of diboson production processes involving combinations of W , Z and isolated photons are summarized. Measurements using data at 7 TeV as well as more recent results using data at 8 TeV are presented. The measurements are performed using leptonic decay modes, including the invisible decay Z → , as well as semileptonic channels. Differential and total cross sections are presented and are used to place constraints on anomalous triple-gauge boson couplings. An overview of these results is given.
117370742
Statistical Mechanics of Wormholes
The statistical mechanics of a gas of Einstein-Kalb-Ramond wormholes is studied in this paper. The wormholes studied are the result of sewing together two Reissner-Nordstrom-type black hole metrics at their horizons. By requiring the stress-energy tensor associated with this geometry to be that of a Kalb-Ramond field, we obtain the mass and Kalb-Ramond `charge` of the wormholes in terms of the parameters describing the mass density, tension and pressure. We investigate the statistical mechanics of this system of wormholes within the context of the statistical bootstrap model. A gas of such wormholes is found to obey the bootstrap condition only for an extreme, non-thermodynamic, energy and `charge` distribution among the particles. We comment briefly on the scattering of quantum wormholes.