2,387 research outputs found

    Undergraduate Catalog of Studies, 2023-2024

    Get PDF

    Undergraduate Catalog of Studies, 2023-2024

    Get PDF

    Undergraduate Catalog of Studies, 2022-2023

    Get PDF

    Design and characterisation of monolithic CMOS detectors for high energy particle physics and SEU radiation tests for ATLAS Inner Tracker Upgrade readout chip

    Get PDF
    This thesis covers the characterisation results and the design of monolithic CMOS detectors designed in TowerJazz 180nm CMOS technology for High Energy Particle Physics applications. Three different detectors have been studied the MALTA, the Mini-MALTA and the MALTA2. The MALTA sensor showed some efficiency losses at the corners of the pixels after irradiation, which meant that it was not suitable for the radiation environments in which it was supposed to be installed. Therefore, the front-end electronics and the fabrication process were modified to overcome this issue. The Mini-MALTA prototype was designed including the above mentioned improvements, fabricated and fully characterised. Finally taking into account all the knowledge acquired during these years of developments another large scale sensor the MALTA2 has been produced which should be radiation tolerant and have very good time resolution. The description and studies of the different architectures used in this family of detectors are covered and a simulation to estimate the bandwidth capabilities have been reported. Furthermore, this work will present characterisation of single event effects in the ITkPixV1, the prototype version of the ATLAS Inner Tracker Upgrade chip for the High Luminosity LHC. Measurements were made in testbeam campaigns with high energy ions and protons to evaluate the level of single event effects in the chip

    A 1.8 V 25 Mbps CMOS single-phase, phase-locked loop-based BPSK, QPSK demodulator

    Get PDF
    A single-phase binary/quadrature phase-shift keying (BPSK/QPSK) demodulator basing on a phase-locked loop (PLL) is described. The demodulator relies on a linear characteristic a rising-edge RESET/SET flip-flop (RSFF) employed as a phase detector. The phase controller takes the average output from the RSFF and performs a sub-ranging/re-scaling operation to provide an input signal to a voltage-controlled oscillator (VCO). The demodulator is truly modular which theoretically can be extended for a multiple-PSK (m-PSK) signal. Symbol-error rate analysis has also been extensively carried out. The proposed BPSK and QPSK demodulators have been fabricated in a 0.18-mm digital complementary metal–oxide–semiconductor (CMOS) process where they operate from a single supply of 1.8 V. At a carrier frequency of 60 MHz, the BPSK and QPSK demodulators achieved maximum symbol rates of 25 and 12.5 Msymb/s while consuming 0.68 and 0.79 mW, respectively. At these maximum symbol rates, the BPSK and QPSK demodulators deliver symbol-error rates less than 7.9×10-10 and 9.8×10-10, respectively where their corresponding energy per bit figures were at 27.2 and 31.7 pJ

    A SciFi tracker for the LHCb experiment

    Get PDF
    The quest to understand the prevalence of matter over antimatter in the observable universe drives the Large Hadron Collider Beauty (LHCb) Experiment at CERN, situated beneath the France-Switzerland border. This thesis focuses on a detector upgrade crucial to enhance the sensitivity of the LHCb Experiment. A key ingredient of this upgrade is the Scintillating Fiber Detector (SciFi) Tracker.The introduction of the SciFi replaced key components like the Outer and Inner Tracker, improving tracking efficiency and spatial resolution.To ensure SciFi's radiation resilience, comprehensive tests were conducted, that revealed effects on Field-Programmable Gate Arrays (FPGAs), including speed degradation, leakage current, re-programmability loss, Single Event Upsets (SEU), and Single Event Latch-ups (SEL).Results indicated that speed degradation, leakage current, and SELs were manageable during the detector's lifetime. However, FPGAs became unprogrammable after a certain radiation exposure, necessitating operational planning. Mitigation strategies, like triple modular redundancy, reduced SEUs to an acceptable level.Mass-produced SciFi modules and readout electronics underwent their first particle beam test, allowing optimization of operating parameters of the front-end electronics, such as clustering coefficients, thresholds, and shaper settings.Resolution analysis demonstrated compliance with detector specifications. With an efficiency surpassing 99\% and a spatial resolution better than 70 µm, SciFi is validated for LHCb operation.As SciFi is commissioned, the configurations explored in this thesis offer valuable insights for optimizing the detector during commissioning and beyond

    Various Applications of Methods and Elements of Adaptive Optics

    Get PDF
    This volume is focused on a wide range of topics, including adaptive optic components and tools, wavefront sensing, different control algorithms, astronomy, and propagation through turbulent and turbid media

    Insect neuroethology of reinforcement learning

    Get PDF
    Historically, reinforcement learning is a branch of machine learning founded on observations of how animals learn. This involved collaboration between the fields of biology and artificial intelligence that was beneficial to both fields, creating smarter artificial agents and improving the understanding of how biological systems function. The evolution of reinforcement learning during the past few years was rapid but substantially diverged from providing insights into how biological systems work, opening a gap between reinforcement learning and biology. In an attempt to close this gap, this thesis studied the insect neuroethology of reinforcement learning, that is, the neural circuits that underlie reinforcement-learning-related behaviours in insects. The goal was to extract a biologically plausible plasticity function from insect-neuronal data, use this to explain biological findings and compare it to more standard reinforcement learning models. Consequently, a novel dopaminergic plasticity rule was developed to approximate the function of dopamine as the plasticity mechanism between neurons in the insect brain. This allowed a range of observed learning phenomena to happen in parallel, like memory depression, potentiation, recovery, and saturation. In addition, by using anatomical data of connections between neurons in the mushroom body neuropils of the insect brain, the neural incentive circuit of dopaminergic and output neurons was also explored. This, together with the dopaminergic plasticity rule, allowed for dynamic collaboration amongst parallel memory functions, such as acquisition, transfer, and forgetting. When tested on olfactory conditioning paradigms, the model reproduced the observed changes in the activity of the identified neurons in fruit flies. It also replicated the observed behaviour of the animals and it allowed for flexible behavioural control. Inspired by the visual navigation system of desert ants, the model was further challenged in the visual place recognition task. Although a relatively simple encoding of the olfactory information was sufficient to explain odour learning, a more sophisticated encoding of the visual input was required to increase the separability among the visual inputs and enable visual place recognition. Signal whitening and sparse combinatorial encoding were sufficient to boost the performance of the system in this task. The incentive circuit enabled the encoding of increasing familiarity along a known route, which dropped proportionally to the distance of the animal from that route. Finally, the proposed model was challenged in delayed reinforcement tasks, suggesting that it might take the role of an adaptive critic in the context of reinforcement learning

    Efficient wireless coverage of in-building environments with low electromagnetic impact

    Get PDF
    The city of tomorrow is a major integrating stake, which crosses a set of major broad spectrum domains. One of these areas is the instrumentation of this city and the ubiquity of the exchange of data, which will give the pulse of this city (sensors) and its breathing in a hyper-connected world within indoor and outdoor dense areas (data exchange, 5G and 6G). Within this context, the proposed doctorate project has the objective to realize cost- and energy- effective, short-range communication systems for the capillary wireless coverage of in-door environments with low electromagnetic impact and for highly dense outdoor networks. The result will be reached through the combined use of: 1) Radio over Fiber (RoF) Technology, to bring the Radio Frequency (RF) signal to the different areas to be covered. 2) Beamforming antennas to send in real time the RF power just in the direction(s) where it is really necessary
    • …
    corecore