A new Global Trigger subsystem will be installed in the Level-0 Trigger as part of HL-LHC Upgrade of ATLAS during the upcoming Long-Shutdown 3. It will feature new and improved trigger hardware and ...algorithms, and an increased maximum output rate of 1 MHz. The Global Trigger will run offline-like trigger algorithms on full-granularity data, gathered from several sub-detectors and trigger-processing subsystems. A single Global Common Module (GCM) hardware is implemented across the Global Trigger system to be used as Multiplexer Processor, Global Event Processor and CTP Interface (gCTPi). This common hardware platform method will minimize the complexity of the firmware and simplify the system design and long-term maintenance. The GCM prototype is an ATCA front form factor board with two Xilinx Virtex UltraScale+ FPGA VU13P and one ZYNQ UltraScale+ FPGA ZU19EG and seventeen 25.78125 Gb/s FireFly duplex optical modules on it. The total power consumption of this board must be less than 350 W, and the temperature of the optical modules should be less than 70 °C in the worst case. The VU13Ps serve as algorithms processor nodes such as MUX, GEP and gCTPi, and the ZU19EG with Peta Linux OS running on it, is used as Command/Control/Readout Unit to configure and monitor the board and communicate with the ATLAS Detector Control System (DCS). The development of an ATCA blade with three large FPGAs and about 200 optical links running at 25Gb/s is a very challenging task, and the successful test results have demonstrated this GCM prototype as an advancement of state-of-the-art electronics module design in HEP experiments. This paper presents the hardware design considerations, functionalities, and performance test results of this GCM prototype.
As part of the ATLAS experiment's Phase-II Upgrade, improved trigger hardware and algorithms will be implemented onto a single-level architecture. The global trigger (GT) subsystem is a new firmware ...(FW)-focused project designed to meet stringent requirements from the high-luminosity runs of the large hadron collider (LHC). The global multiplexer (MUX) is the input aggregating stage of the GT; it performs three main tasks: 1) aggregating data from several sources, connected with more than 2300 input fibers, under different protocols; 2) time-multiplexing the incoming data, to sort the packets per bunch-crossing (BC) events, by compensating the relative skews across the various serial input channels; and 3) transmitting, in a round-robin fashion, the sorted BC data to the global event processor (GEP) array, which is the following stage of the GT subsystem and is composed of 48 nodes, each one processing a single BC event. Two MUX FW prototypes for the Global Feature EXtractor (gFEX, part of the liquid argon calorimeter trigger) inputs have been designed, implemented, and validated on a gFEX production board, for up to 72 input and output channels. A four-channel version has been completed with I/O interfaces and validated in a full-chain design, accepting 8b/10b encoded inputs at 11.2 Gb/s and transmitting at 25.78125 Gb/s under Xilinx Aurora 64b/66b protocol. The total latency has been benchmarked in all of its contributing subcomponents and proven to meet the requirements from the Technical Design Report for the Phase-II Upgrade of the trigger and data acquisition system.
UV Nanoimprint Lithography combined with lens molding represent a flexible and low-cost pattern replication technique which was investigated with focus on pattern shape, size and imprinted surface ...quality. The flexibility of this method in imprinting different shape patterns by means of adjustable base layer thickness as well as the reliable fabrication of high quality surfaces using both standard and high refractive index resins was demonstrated using SmartNIL ® processes. The use of a Moiré-type lens master template fabricated by two-photon technology was proven for SmartNIL ® replication, providing an attractive solution for both prototyping, as well as high volume manufacturing processes.Finally, the fabrication of large lenses geometry with reliable shape replication for use in microoptical components was proven by means of UV molding processes at wafer level scale.
Abstract
The High-Luminosity Large Hadron Collider is expected to start operations in the middle of 2027, to deliver more than ten times the integrated luminosity of the Large Hadron Collider Runs ...1–3 combined (up to 4000 fb
−1
). Meeting these requirements poses significant challenges to the hardware design of the trigger and data acquisition system. Global trigger is a new subsystem in the ATLAS phase-II upgrade, which will bring event filter-like capability to the level-0 trigger system. A common hardware platform in Advanced Telecommunications Computing Architecture form factor named Global Common Module is proposed to be configured as processor nodes in the global trigger. To mitigate the risk and simplify the Global Common Module hardware design, a Generic Rear Transition Module is being developed. The Generic Rear Transition Module, which has been implemented with a Xilinx Versal Prime Field Programmable Gate Array and sufficient multi-gigabit transceivers, cannot only achieve system control and communication with the Front-End Link eXchange, but also provide additional processing or readout capacity.
As part of the ATLAS Phase-I Upgrade, the global Feature EXtractor (gFEX) is one of several hardware modules designed to help maintain the ATLAS Level-1 trigger acceptance rate with the increasing ...Large Hadron Collider (LHC) luminosity and the increasing Pile-Up conditions. The gFEX is used to identify patterns of energy associated with the hadronic decays of high momentum Higgs, W & Z bosons, top quarks, and exotic particles in real time at the 40 MHz LHC bunch crossing rate. The board is required to receive coarse-granularity (Δη×Δϕ=0.2×0.2 gTower) information from the entire ATLAS calorimeters on 276 optical fibers. A prototype v1 with one Xilinx ZYNQ FPGA, and one Vertex-7 FPGA for technology validation has been designed and tested in 2015. With the lessons learned from the prototype v1, a prototype v2 with three Vertex UltraScale FPGAs and one ZYNQ FPGA has been implemented to verify full functionalities of gFEX in 2016. Based on the prototype v2 design, a prototype v3, the final gFEX prototype, is implemented, which is an ATCA module consisting of three Vertex UltraScale+ FPGAs, one ZYNQ UltraScale+ SoC, and 35 MiniPODs. This board receives up to 300 fiber optical links from calorimeters and transmits trigger data on 96 links to the to the ATLAS Level-1 Topological trigger (L1Topo 1) at the speed up to 12.8 Gb/s. There are also 24 electrical links on board for communication between two FPGAs with the speed up to 25.6 Gb/s. The performance of three prototype boards have been tested and evaluated. For the prototype v3 board, the high-speed optical links are stable at 12.8 Gb/s with Bit Error Ratio (BER) < 1 × 10-15. The low-latency parallel GPIO (General Purpose I/O) buses between FPGAs are stable at 1.12 Gb/s. The peripheral components of ZYNQ UltraScale+ SoC, such as 16 GB DDR4 DIMM, UART, SPI flashes, and Ethernet, have also been verified. The test results of the prototype v3 board validate the gFEX technologies, architecture and full functionalities. Now the final production board is being produced.
Improved Analysis of Timber Rivet Connections Stahl, Douglas C; Wolfe, Ronald W; Begel, Marshall
Journal of structural engineering (New York, N.Y.),
08/2004, Letnik:
130, Številka:
8
Journal Article
Recenzirano
Timber rivets are fasteners for glued-laminated timber construction that were first sanctioned for use in the United Stated by adoption in the 1997 National Design Specification for Wood Construction ...(NDS). Rivet connections can exhibit a brittle failure when a volume of wood bounded by the perimeter of the rivets pulls out from the timber, or a ductile failure due to a combination of fastener yielding and localized wood crushing. The NDS approach to the former failure mode is so complex that closed form solution is not possible and designers must refer to limited tabular data, and the NDS approach to the latter failure mode is inconsistent with the approach used for other dowel fasteners. This paper describes an improved analysis based on the capacity of wood failure planes and the well-established dowel fastener yield model. Results of tests of large rivet connections highlighting the crossover from ductile to brittle failure modes verify the analysis. In addition, these results provide the first data for timber rivets in Southern Pine glued-laminated timber.
Celotno besedilo
Dostopno za:
DOBA, FGGLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report on the calibration and performance of a large lead liquid-argon electromagnetic calorimeter used by experiment E706 at Fermilab. The reconstructed π
0 mass was used to calibrate the energy ...response of the calorimeter. The systematic uncertainty in the linearity and uniformity of the mean-energy response of the calorimeter after calibration was found to be less than ±0.5% for the sample of data analyzed. Detector characteristics, including sampling fluctuations and position resolution, are discussed.
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