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.
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.
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.
15637889
The Cryogenic Performances of Specific Optical and Electrical Components for a Liquid Argon Time Projection Chamber
Abstract In this paper we present a cryogenic performance study of specific optical and electrical components for the Liquid Argon Time Projection Chamber (LArTPC), a potential far site detector technology of the long baseline neutrino experiment (LBNE). We have confirmed that an LVDS driver can drive a 20-meter CAT5E twisted pair up to 1 gigabit per second at liquid nitrogen temperature (77 K). We have verified that a 16:1 serializer Application Specific Integrated Circuit (ASIC), three types of laser diodes, optical fibers and connectors, and field-programming gate arrays (FPGAs) continue to function at 77 K. A variety of commercial resistors and capacitors have been tested at 77 K. All tests we have conducted show that the cold front-end electronics is promising.
122670904
The design of 8-Gbps VCSEL drivers for ATLAS liquid Argon calorimeter upgrade
We present designs and preliminary test results of LOCld1 and LOCld4, VCSEL drivers in a commercial 0.25-mu m m Silicon-on-Sapphire (SoS) CMOS process for ATLAS liquid Argon calorimeter upgrade. Active shunt peaking, multiple-stage amplification and higher voltage supply are used to achieve the data rate of 8 Gbps. LOCld1 is a single channel VCSEL driver with a differential output, while LOCld4 has four channels with single-ended open-drain outputs. Both drivers have tunable modulation and peaking strength. Bias current for VCSEL is also embedded.
120130481
Radiation hardness of the 1550 nm edge emitting laser for the optical links of the CDF silicon tracker
Radiation hardness is investigated for the laser transmitter of the optical links used for the CDF Run II silicon tracker. Beam tests were conducted with 30, 63, and 200 MeV protons with radiation doses up to 2 Mrad. The laser transmitter consists of an edge-emitting-type laser diode array and a BiCMOS driver chip. The laser light degradation is approximately linear to the radiation dose. The light degradation is about 10% at 200 krad. The radiation tolerance is expected to suffice for the CDF Run II operation.
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.