The CERN RD53 collaboration was founded to tackle the extraordinary challenges associated with the design of pixel readout chips for the innermost layers of particle trackers at future high energy ...physics experiments. Around 20 institutions are involved in the collaboration, which has the support of both ATLAS and CMS experiments. The goals of the collaboration include the comprehensive understanding of radiation effects in the 65 nm technology, the development of tools and methodology to efficiently design large complex mixed signal chips and, ultimately, the development of a full size readout chip featuring a 400 × 400 pixel array with 50μm pitch. In August 2017, the collaboration submitted the large scale chip RD53A, integrating a matrix of 400 × 192 pixels and embodying three different analog front-end designs. This work discusses the characteristic of the RD53A chip, with some emphasis on the analog processors, and presents the first test results on the pixel array.
•High particle rates and radiation levels will be reached at the HL-LHC.•New pixel chips for the phase II upgrades of CMS and ATLAS are required.•The RD53A chip has been designed in the framework of the RD53 Collaboration.•Three analog front-ends flavors are integrated in RD53A.•The paper presents the main preliminary results coming from RD53A characterization.
We propose a new generation of VLSI processors for pattern recognition, based on associative memory architecture, optimized for online track finding in high-energy physics experiments. We describe ...the architecture, the technology studies and the prototype design of a new associative memory project: it maximizes the pattern density on the ASIC, minimizes the power consumption and improves the functionality for the fast tracker processor proposed to upgrade the ATLAS trigger at LHC.
This paper presents the design of an SRAM cell in 28 nm, specifically designed to avoid metastability at start-up. Metastable operation is avoided by unbalancing the size of transistors. Extensive ...simulations have confirmed that the probability of metastable operation is greatly reduced.
The FastTracKer (FTK), a hardware dedicated processor, performs fast and precise online full track reconstruction at the ATLAS experiment, within an average latency of few dozens of microseconds. ...Before production of the final system for tracking in high-occupancy conditions with the best of available technology, we plan to use existing prototypes of the FTK hardware to exercise its functions in the ATLAS environment. We describe the “baby FTK”, consisting of a few hardware elements implementing the first stages of the system, and discuss our plans to grow the system into a full-functionality FTK “vertical slice” covering a small projective wedge of the detector. We report on the performances and structure of the “baby FTK”, including the pixel/strip hit clustering (clustering mezzanine), hit organization and distribution (EDRO) and the Associative Memory pattern recognition function. We describe briefly also the possible future evolution including the addition of the Track Fitter.
The increase of luminosity at HL-LHC will require the introduction of tracker information at Level-1 trigger system for the experiments to maintain an acceptable trigger rate to select interesting ...events despite the one order of magnitude increase in the minimum bias interactions. To extract in the required latency the track information a dedicated hardware has to be used. We present the tests of a prototype system (Pattern Recognition Mezzanine) as core of pattern recognition and track fitting for HL-LHC ATLAS and CMS experiments, combining the power of both Associative Memory custom ASIC and modern Field Programmable Gate Array (FPGA) devices.
Real time event reconstruction plays a fundamental role in High Energy Physics experiments. The CDF experiment at the Tevatron collider performs a fast online reconstruction of high-resolution tracks ...using the Silicon Vertex Trigger (SVT). We will describe the architecture, the performance and the impact on CDF physics program of a next generation online track fitter, the GigaFitter, developed to improve the SVT track reconstruction efficiency as the Tevatron instantaneous luminosity increases. The core of the GigaFitter is implemented in a modern Xilinx Virtex-5 FPGA chip, rich in powerful DSP arrays. The higher computation power allows to perform many tasks in parallel, reducing the track parameter reconstruction to a few clock cycles: as a result, the GigaFitter can perform more than one fit per nanosecond. The Gigafitter installation and commissioning were successfully completed in February 2010: 12 Track Fitter boards, one per each azimuthal sector of the silicon detector, have been replaced by a single Gigafitter board receiving the data from the entire tracking detector. Besides being much more compact and robust than the previous system, the Gigafitter increases the SVT track reconstruction efficiency and acceptance and copes more effectively with the high-occupancy events that occur frequently at the high luminosities the Tevatron currently delivers. Moreover, its architecture is general enough to be adapted to different experimental environments: the experience gained with the Gigafitter upgrade will be essential for future SVT-like tracking processor such as FTK at Atlas experiment.
The SuperB asymmetric e + e - collider has been designed to deliver a luminosity greater than 10 36 cm -2 s -1 maintaining moderate beam currents. Comparing to current B-Factories, the reduced ...center-of-mass boost of the SuperB machine requires an improved vertex resolution to allow precision measurements sensitive to New Physics. Therefore the SuperB Silicon Vertex Tracker will be equipped with an innermost Layer0 with a radius of about 1.5 cm, high granularity, low material budget and able to withstand a background rate of several MHz/cm 2 . We report on the status of the R&D on the different options under study for the Layer0: DNW MAPS, hybrid pixels and thin pixels developed with vertical integration technology.
Modern experiments search for extremely rare processes hidden in much larger background levels. As the experiment complexity, the accelerator backgrounds and luminosity increase we need increasingly ...exclusive selections to efficiently select the rare events inside the huge background. We present a fast, high-quality, track-based event selection for the self-triggered SLIM5 silicon telescope. This is an R&D experiment whose innovative trigger will show that high rejection factors and manageable trigger rates can be achieved using fine-granularity, low-material tracking detectors.
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