25345531
A low-latency, small-form-factor optical link for the high-luminosity LHC experiments
We present a low-latency, small-form-factor optical link designed for the high-luminosity LHC experiments in which the latency and form factor are critical. The optical link on the transmitter side is composed of a transmitter ASIC and a custom-made optical transmitter module. The transmitter ASIC includes an encoder and a serializer. Two serializer ASIC prototypes, operating at 5 and 8 Gbps per channel respectively, have been designed and tested. A low-latency, low-overhead encoder has been verified in FPGAs and is being integrated into a two-channel, 8:1 transmitter ASIC with each channel operating at 5.12 Gbps. A prototype of the custom-made optical transmitter module (called MTx) with separate transmitter optical sub-assemblies (TOSAs) has been demonstrated. A Vertical-Cavity Surface-Emitting Laser (VCSEL) driver ASIC has been developed and will replace the commercial VCSEL laser driver used in the current MTx prototypes. The latency of the whole link, including the transmitter latency and the receiver latency but not including the latency of the fiber, is estimated to be less than 80 ns. The size of the MTx is 42 mm × 15 mm × 6 mm.
62809210
Radiation hardness studies of VCSELs and PINs for the opto-links of the Atlas SemiConductor Tracker
We study the radiation hardness of the Vertical Cavity Surface Emitting Laser diodes (VCSELs) and the epitaxial silicon PIN diodes that will be used for the Atlas SemiConductor Tracker at the CERN Large Hadron Collider. The tests were conducted with 200MeV protons to a fluence of 4 10 p=cm and with 20MeV (average energy) neutrons to 7:7 10 n=cm. The radiation damage of the VCSELs and PINs and the annealing characteristics are presented. r 2007 Elsevier B.V. All rights reserved. PACS: 07.89+b; 42.60. v; 42.79. e; 42.88+h; 85.60 q
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.
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.
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.
119162753
On the gauge features of gravity on a Lie algebroid structure
We present the geometric formulation of gravity based on the mathematical structure of a Lie Algebroid. We show that this framework provides the geometrical setting to describe the gauge propriety of gravity.