2,984 research outputs found
Feedback-Optimized Operations with Linear Ion Crystals
We report on transport operations with linear crystals of 40Ca+ ions by
applying complex electric time-dependent potentials. For their control we use
the information obtained from the ions' fluorescence. We demonstrate that by
means of this feedback technique, we can transport a predefined number of ions
and also split and unify ion crystals. The feedback control allows for a robust
scheme, compensating for experimental errors as it does not rely on a precisely
known electrical modeling of the electric potentials in the ion trap
beforehand. Our method allows us to generate a self-learning voltage ramp for
the required process. With an experimental demonstration of a transport with
more than 99.8 % success probability, this technique may facilitate the
operation of a future ion based quantum processor
Some solutions, some problems, and some questions
"December, 1981.""National Science Foundation ... Grant ECS-8012668"Alan S. Willsky
Signal Formation Processes in Micromegas Detectors and Quality Control for large size Detector Construction for the ATLAS New Small Wheel
The Micromegas technology is one of the most successful MPGD concepts and
widely utilized in nuclear and particle physics experiments. Twenty years of
research and development rendered the technology sufficiently mature to be
selected as precision tracking detector for the New Small Wheel (NSW) upgrade
of the ATLAS Muon spectrometer. This will be the first large scale application
of Micromegas in one of the major LHC experiments. The studies on signal
formation in Micromegas focuses on the microscopic signal electron loss
mechanisms and the amplification processes in electron gas interaction. Based
on a model of detector parameter dependencies, these processes are scrutinized
in an iterating comparison between exper- imental results, theory prediction of
the macroscopic observables and process simulation on the microscopic level.
Utilizing the specialized detectors developed in the scope of this thesis as
well as refined simulation algorithms, an unprecedented level of accuracy in
the process description is reached, deepening the understanding of the
fundamental process in gaseous detectors. The second part is dedicated to the
challenges arising with the large scale Micro- megas production for the ATLAS
NSW. A selection of technological choices, are discussed alongside a final
report on two production related tasks addressing the detectors core
components: For the industrial production of resistive anode PCBs a detailed
quality control (QC) and quality assurance (QA) scheme as well as the therefore
required testing tools have been developed. In parallel the study on micromesh
parameter optimization and production feasibility resulted in the selection of
the proposed mesh by the NSW community. The successful completion of both tasks
were important milestones towards the construction of large size Micromegas
detectors clearing the path for NSW series production.Comment: Version 2: Added reference for figure 6.8, subesequent reference
numbers update
Novel Approaches for Nondestructive Testing and Evaluation
Nondestructive testing and evaluation (NDT&E) is one of the most important techniques for determining the quality and safety of materials, components, devices, and structures. NDT&E technologies include ultrasonic testing (UT), magnetic particle testing (MT), magnetic flux leakage testing (MFLT), eddy current testing (ECT), radiation testing (RT), penetrant testing (PT), and visual testing (VT), and these are widely used throughout the modern industry. However, some NDT processes, such as those for cleaning specimens and removing paint, cause environmental pollution and must only be considered in limited environments (time, space, and sensor selection). Thus, NDT&E is classified as a typical 3D (dirty, dangerous, and difficult) job. In addition, NDT operators judge the presence of damage based on experience and subjective judgment, so in some cases, a flaw may not be detected during the test. Therefore, to obtain clearer test results, a means for the operator to determine flaws more easily should be provided. In addition, the test results should be organized systemically in order to identify the cause of the abnormality in the test specimen and to identify the progress of the damage quantitatively
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EXTREME DYNAMICS OF NANOMATERIALS UNDER HIGH-RATE MECHANICAL STIMULI
Nanomaterials demonstrate novel mechanical properties attributed to the extremely large interfacial area. At quasi-static rates, the interfacial interactions are crucial in mechanical behaviors, however, materials under extreme mechanical stimuli are rarely studied at nanoscale. With an advanced laser-induced projectile impact test, we perform supersonic impact of micro-projectiles on polymer films, multilayer graphene, carbon- based nanocomposites membranes as well as individual micro-fibers, to study the interface interactions in the high-rate regime, and develop a simplified model to characterize the ballistic performance of materials
R&D Proposal Development of Micro-Pattern Gas Detector Technologies
Development of advanced gas-avalanche detector technologies and associated electronic-readout systems for applications in basic and applied researc
Texture and Colour in Image Analysis
Research in colour and texture has experienced major changes in the last few years. This book presents some recent advances in the field, specifically in the theory and applications of colour texture analysis. This volume also features benchmarks, comparative evaluations and reviews
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