Long-term prediction test procedure for most ICs, based on linear response theory

Experimentally, thermal annealing is known to be a factor which enables a number of different integrated circuits (IC's) to recover their operating characteristics after suffering radiation damage in the space radiation environment; thus, decreasing and limiting long term cumulative total-dose effects. This annealing is also known to be accelerated at elevated temperatures both during and after irradiation. Linear response theory (LRT) was applied, and a linear response function (LRF) to predict the radiation/annealing response of sensitive parameters of IC's for long term (several months or years) exposure to the space radiation environment were constructed. Compressing the annealing process from several years in orbit to just a few hours or days in the laboratory is achieved by subjecting the IC to elevated temperatures or by increasing the typical spaceflight dose rate by several orders of magnitude for simultaneous radiation/annealing only. The accomplishments are as follows: (1) the test procedure to make predictions of the radiation response was developed; (2) the calculation of the shift in the threshold potential due to the charge distribution in the oxide was written; (3) electron tunneling processes from the bulk Si to the oxide region in an MOS IC were estimated; (4) in order to connect the experimental annealing data to the theoretical model, constants of the model of the basic annealing process were established; (5) experimental data obtained at elevated temperatures were analyzed; (6) time compression and reliability of predictions for the long term region were shown; (7) a method to compress test time and to make predictions of response for the nonlinear region was proposed; and (8) nonlinearity of the LRF with respect to log(t) was calculated theoretically from a model

Coupled structural, thermal, phase-change and electromagnetic analysis for superconductors, volume 2

Two families of parametrized mixed variational principles for linear electromagnetodynamics are constructed. The first family is applicable when the current density distribution is known a priori. Its six independent fields are magnetic intensity and flux density, magnetic potential, electric intensity and flux density and electric potential. Through appropriate specialization of parameters the first principle reduces to more conventional principles proposed in the literature. The second family is appropriate when the current density distribution and a conjugate Lagrange multiplier field are adjoined, giving a total of eight independently varied fields. In this case it is shown that a conventional variational principle exists only in the time-independent (static) case. Several static functionals with reduced number of varied fields are presented. The application of one of these principles to construct finite elements with current prediction capabilities is illustrated with a numerical example

Nano-structured platforms as a spectroscopic tool

Nano-structured platforms have been studied for the purpose of enhancing weak fluorescence signals. Each platform was constructed as a thin oxide layer on top of a metal (aluminum) The oxide was perforated with hexagonal array of nano-holes. The pitch of the array was much smaller than the optical wavelengths used. Surface charge waves (Surface Plasmons) could be excited when the platform was oriented at specific direction with respect to the incident optical beam. At this point one can demonstrate that fluorescence signals could be amplified. Since the oxide (alumina) is bio-compatible, one can envision using such platforms in the study of bio-species with fluorescencing biomarkers. Moreover, when imbedding dye chromophores in the structure\u27s nano-pores, one can show that such construction exhibits threshold and gain for the related fluorescence signals

Different Approaches of Numerical Analysis of Electromagnetic Phenomena in Shaded Pole Motor with Application of Finite Elements Method

In this paper is used Finite Element Method-FEM for analysis of electromagnetic quantities of small micro motor – single phase shaded pole motor-SPSPM. FEM is widely used numerical method for solving nonlinear partial differential equations with variable coefficients. For that purpose motor model is developed with exact geometry and material’s characteristics. Two different approaches are applied in FEM analysis of electromagnetic phenomena inside the motor: magneto-static where all electromagnetic quantities are analysed in exact moment of time meaning frequency f=0 Hz and timeharmonic magnetic approach where the magnetic field inside the machine is time varying, meaning frequency f=50 Hz. Obtained results are presented and compared with available analytical result

Formation Evaluation Using Temperature Buildup Curves.

This dissertation presents a formation evaluation method using the formation thermal properties (heat conductivity and volumetric heat capacity). The formation heat conductivity is determined by a modified Horner method, and the volumetric heat capacity is determined by the temperature buildup curve matching method. The comparisons show that the pressure and temperature diffusivity equations and initial and boundary conditions are similar. Therefore, the temperature diffusivity equation can be solved by a method similar to that used in solving the pressure diffusivity equation. The wellbore fluid storage effect is an important boundary condition and is considered in the solution of the temperature diffusivity equation. From the solution of the temperature diffusivity equation, the Horner method used in the formation pressure analysis can be used in determining the formation heat conductivity from the temperature buildup data. However, the conventional Horner method is impractical because the temperature buildup time required exceeds 600 hours. The modified Horner method proposed requires only a little more than 30 hours of temperature buildup time. The theoretical temperature buildup curves can be calculated based on the solution of the temperature diffusivity equation. Curve matching between the calculated and the measured temperature buildup curves can be used to determine the formation heat conductivity. An improved heat conductivity equation for porous rock with multi-phase saturation is developed. The rock porosity and saturations can be determined with the improved heat conductivity equation and the weighted average equation of the volumetric heat capacity. A crossplot technique is developed to achieve this determination. The temperature drawdown and buildup data were recorded at four intervals in a LSU test well. The formation thermal properties were calculated from the temperature buildup data. The formation porosities and saturations were computed with the formation thermal properties. The calculation results agree with the interpretation results of the pulsed neutron log

High-resolution imaging of transport processes with GPR full-waveform inversion

Imaging subsurface small-scale features and monitoring transport of tracer plumes at a fine resolution is of interest to characterize transport processes in aquifers. Full-waveform inversion (FWI) of crosshole ground penetrating radar (GPR) measurements enables aquifer characterization at decimeter-scale resolution. GPR FWI provides 2D tomograms of the subsurface properties, the dielectric permittivity (ε) and electrical conductivity (σ), which can be correlated with hydrological properties. In the framework of the thesis, we conducted synthetic and experimental tracer tests that were monitored using time-lapse crosshole GPR full-waveform inversion results, to test the potential and limitation to reconstruct the tracer plume. For the synthetic test, we generated a realistic high resolution aquifer model based on previous hydrological and GPR FWI data from the Krauthausen test site in order perform a transport simulation that represents reasonable heterogeneity of the tracer concentration. Using petrophysical relations, we converted the concentration distribution to dielectric properties of specific tracers: saltwater (increase σ only), desalinated water (decrease σ only) and ethanol (decrease in both σ and ε). One important aspect of the GPR FWI is to investigate an optimal way to define adequate starting models especially for the time-lapse data. Therefore, we investigated three different starting model options in the synthetic test, resulting that ε and σ models from the background provide the most accurate FWI of time-lapse data. Hereby, both ε and σ FWI results have shown the potential to derive time-lapse changes. The gained insights of the synthetic optimization tests are applied for an experimental test. To prove the potential of the crosshole GPR FWI also under realistic conditions, we performed an experimental salt tracer experiment at the Krauthausen test site. Thereby, we injected to the sandy aquifer a salt tracer, and monitored the tracer development using crosshole GPR over a timeframe of 14 days within 5 crosshole planes in an area of 11x10 m. These time-lapse data are independently inverted using the background models of each plane as starting models as proposed from the synthetic study to derive the best FWI results. We investigated the consistency of the reconstruction of the plume by temporal and spatial continuity across neighboring planes, by correlating with borehole logging data, and with expectations based on previous tracer experiments from the same site. One challenge arise from the time-lapse GPR data caused by the change of the borehole filling properties over the time and transport of the plume. The salt and freshwater mixture in the tubes couple with the borehole antennae thus influence the GPR data. Fortunately, the processing for the FWI enables accounting this effect by estimating effective source wavelets for each time step and each plane, which compensate for borehole filling effects caused by the salt tracer. If these borehole filling effects would not be considered, errors in the results would occur. Performing the FWI considering the corrected effective source wavelets allows recovery of the aquifer models independently from saltwater-antennae effects. Such effects cannot be incorporated using standard ray-based approaches. In contrast from the synthetic tracer test, investigation of the best starting model for experimental data showed that σ homogenous model rather than from FWI background provides more accurate results for FWI of time-lapse data. This can be explained that possible errors in the FWI background results caused by measurement or starting model uncertainties, are forcing the FWI with these models to be trapped in a local minimum. The time-lapse GPR FWI has shown a reliable manifestation of a tracer of about 0.2 m resolution, which was not observed before from other geophysical monitoring techniques. These improved and higher resolution images of such a tracer transport can help in future to better constraint hydrological properties of interest for hydrological models. In this thesis, we have shown for the first time the potential of the GPR FWI to characterize and monitor tracer experiments using crosshole GPR data. Especially, the application to salt tracers, which traditionally were investigated with ERT, is now also possible with GPR and higher resolution images of the tracer transport are possible to obtain

Active and Fast Tunable Plasmonic Metamaterials

Active and Fast Tunable Plasmonic Metamaterials is a research development that has contributed to studying the interaction between light and matter, specifically focusing on the interaction between the electromagnetic field and free electrons in metals. This interaction can be stimulated by the electric component of light, leading to collective oscillations. In the field of nanotechnology, these phenomena have garnered significant interest due to their ability to enable the transmission of both optical signals and electric currents through the same thin metal structure. This presents an opportunity to connect the combined advantages of photonics and electronics within a single platform. This innovation gives rise to a new subfield of photonics known as plasmonic metamaterials.Plasmonic metamaterials are artificial engineering materials whose optical properties can be engineered to generate the desired response to an incident electromagnetic wave. They consist of subwavelength-scale structures which can be understood as the atoms in conventional materials. The collective response of a randomly or periodically ordered ensemble of such meta-atoms defines the properties of the metamaterials, which can be described in terms of parameters such as permittivity, permeability, refractive index, and impedance. At the interface between noble metal particles and dielectric media, collective oscillations of the free electrons in the metal particles can be resonantly excited, known as plasmon resonances. This work considered two plasmon resonances: localised surface plasmon resonances (LSPRs) and propagating surface plasmon polaritons (SPPs).The investigated plasmonic metamaterials, designed with specific structures, were considered for use in various applications, including telecommunications, information processing, sensing, industry, lighting, photovoltaic, metrology, and healthcare. The sample structures are manufactured using metal and dielectric materials as artificial composite materials. It can be used in the electromagnetic spectrum's visible and near-infrared wavelength range. Results obtained proved that artificial composite material can produce a thermal coherent emission at the mid-infrared wavelength range and enable active and fast-tunable optoelectronic devices. Therefore, this work focused on the integrated thermal infrared light source platforms for various applications such as thermal analysis, imaging, security, biosensing, and medical diagnosis. Enabled by Kirchhoff's law of thermal radiation, this work combined the concepts of material absorption with material emission. Hence, the results obtained proved that this approach enhances the overall performance of the active and fast-tunable plasmonic metamaterial in terms of with effortless and fast tunability. This work further considers the narrow line width of the coherent thermal emission, tunable emission, and angular tunable emission at the mid-infrared, which are achieved through plasmonic stacked grating structure (PSGs) and plasmonic infrared absorber structure (PIRAs).Three-dimensional (3D) plasmonic stacked gratings (PSGs) was used to create a tunable plasmonic metamaterial at optical wavelengths ranging from 3 m to 6 m, and from 6m to 9 m. These PSGs are made of a metallic grating with corrugations caused by narrow air openings, followed by a Bragg grating (BG). Additionally, this work demonstrated a thermal radiation source customised for the mid-infrared wavelength range of 3 μm to 5 μm. This source exhibits intriguing characteristics such as high emissivity, narrowband spectra, and sharp angular response capabilities. The proposed thermal emitter consists of a two-dimensional (2D) metallic grating on top of a one-dimensional dielectric BG.Results obtained presented a plasmonic infrared absorber (PIRA) graphene nanostructure designed for a wavelength range of 3 to 14 μm. It was observed and concluded that this wavelength range offers excellent opportunities for detection, especially when targeting gas molecules in the infrared atmospheric windows. The design framework is based on active plasmon control for subwavelength-scale infrared absorbers within the mid-infrared range of the electromagnetic spectrum. Furthermore, this design is useful for applications such as infrared microbolometers, infrared photodetectors, and photovoltaic cells.Finally, the observation and conclusion drawn for the sample of nanostructure used in this work, which consists of an artificial composite arrangement with plasmonic material, can contribute to a highly efficient mid-infrared light source with low power consumption, fast response emissions, and is a cost-effective structure

Plasma Electronics

Contains research objectives and reports on twelve research projects.National Science Foundation under Grant G-9330U. S. Navy (Office of Naval Research) under Contract Nonr-1841(78)U. S. NavyLincoln Laboratory, Purchase Order DDL B-00306U. S. ArmyU. S. Air Force under Air Force Contract AF19(604)-740

Plasma Electronics

Contains reports on nine research projects.U. S. Air Force under Air Force Contract AF 19(604)-7400National Science Foundation under Grant G-9330U.S.Navy(Office of Naval Research)under Contract Nonr-1841(78)U. S. ArmyLincoln Laboratory, Purchase Order DDL B-00337U. S. Nav