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Effect Of Friction Stir Processing On Microstructure And Tensile Properties Of An Investment Cast Al-7si-0.6mg Alloy, Saumyadeep Jana, Rajiv S. Mishra, John A. Baumann, Glenn J. Grant Oct 2010

Effect Of Friction Stir Processing On Microstructure And Tensile Properties Of An Investment Cast Al-7si-0.6mg Alloy, Saumyadeep Jana, Rajiv S. Mishra, John A. Baumann, Glenn J. Grant

Materials Science and Engineering Faculty Research & Creative Works

Friction stir processing (FSP) is emerging as a promising tool for microstructural modification. the current study assesses the effects of FSP on the microstructure and mechanical properties of an investment cast Al-7Si-Mg alloy. FSP eliminates porosity and significantly refines eutectic Si particles. the extent of particle refinement varied with changes in processing conditions. a high tool rotation rate and a low-to-intermediate tool traverse speed generated a higher volume fraction of finer particles. Tensile ductility changed significantly as a result of FSP, whereas ultimate tensile strength improved only marginally. Yield strength was similar in both cast and FSP samples under various …

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Complex Impedance Study Of Fine And Coarse Grain Tio2 Ceramics, Sheng Chao, Vladimir Petrovsky, Fatih Dogan Oct 2010

Complex Impedance Study Of Fine And Coarse Grain Tio2 Ceramics, Sheng Chao, Vladimir Petrovsky, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Titanium dioxide (TiO2) ceramics with various grain sizes were investigated by impedance spectroscopy techniques. Dielectric loss peak identified in coarse grain TiO2 was attributed to space charge polarization occurring at the grain boundaries. Electric modulus representation of the impedance data showed two types of relaxation processes in coarse grain TiO2, whereas only one type was observed in fine grain TiO2. Long-range migration of oxygen vacancies was found to be the dominant conduction mechanism for fine grain TiO2, while electron hopping between localized states was attributed to dielectric relaxation in coarse grain …

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Scale Dependence Of Radar Rainfall Uncertainty: Initial Evaluation Of Nexrad's New Super-Resolution Data For Hydrologic Applications, Bong Chul Seo, Witold F. Krajewski Oct 2010

Scale Dependence Of Radar Rainfall Uncertainty: Initial Evaluation Of Nexrad's New Super-Resolution Data For Hydrologic Applications, Bong Chul Seo, Witold F. Krajewski

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study explores the scale effects of radar rainfall accumulation fields generated using the new super-resolution level II radar reflectivity data acquired by the Next Generation Weather Radar (NEXRAD) network of the Weather Surveillance Radar-1988 Doppler (WSR-88D) weather radars. Eleven months (May 2008-August 2009, exclusive of winter months) of high-density rain gauge network data are used to describe the uncertainty structure of radar rainfall and rain gauge representativeness with respect to five spatial scales (0.5, 1, 2, 4, and 8 km). While both uncertainties of gauge representativeness and radar rainfall show simple scaling behavior, the uncertainty of radar rainfall is …

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Robust Mimo Underwater Acoustic Communications Using Turbo Block Decision-Feedback Equalization, Jun Tao, Yahong Rosa Zheng, Chengshan Xiao, T. C. Yang Oct 2010

Robust Mimo Underwater Acoustic Communications Using Turbo Block Decision-Feedback Equalization, Jun Tao, Yahong Rosa Zheng, Chengshan Xiao, T. C. Yang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a robust detection scheme is proposed for high data rate single-carrier multiple-input multiple-output (MIMO) underwater acoustic communications. the new scheme adopts turbo block decision-feedback equalization, where the soft-decision equalizer performs successive soft interference cancellation of both the InterSymbol interference in the time domain, and the multiplexing interference in the space domain. Attributed to the inherent advantage of the block decision-feedback equalizer (BDFE) over other conventional equalizers, the MIMO turbo detection algorithm provides high performance with fast convergence speed. with the interblock interference properly removed, the MIMO BDFE is performed with overlapped information blocks without guard intervals, thus …

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Nonlinear Control Of Facts Controllers For Damping Interarea Oscillations In Power Systems, Mahyar Zarghami, Jagannathan Sarangapani, Mariesa Crow Oct 2010

Nonlinear Control Of Facts Controllers For Damping Interarea Oscillations In Power Systems, Mahyar Zarghami, Jagannathan Sarangapani, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a new nonlinear control of flexible ac transmission systems (FACTS) controllers for the purpose of damping interarea oscillations in power systems. FACTS controllers consist of series, shunt, or a combination of series-shunt devices which are interfaced with the bulk power system through injection buses. Controlling the angle of these buses can effectively damp low frequency interarea oscillations in the system. The proposed control method is based on finding an equivalent reduced affine nonlinear system for the network from which the dominant machines are extracted based on dynamic coherency. It is shown that if properly selected, measurements obtained …

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The Missouri Miner, September 30, 2010 Sep 2010

The Missouri Miner, September 30, 2010

The Missouri Miner Newspaper

No abstract provided.

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The Missouri Miner, September 23, 2010 Sep 2010

The Missouri Miner, September 23, 2010

The Missouri Miner Newspaper

No abstract provided.

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Real-Time Study Of A Current Controlled Plug-In Vehicle For Vehicle-To-Grid Transaction, P. Mitra, Ganesh K. Venayagamoorthy, Keith Corzine Sep 2010

Real-Time Study Of A Current Controlled Plug-In Vehicle For Vehicle-To-Grid Transaction, P. Mitra, Ganesh K. Venayagamoorthy, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

A real-time model of a current controlled plugin electric vehicle (PEV) parking lot (SmartPark) has been presented in this paper. the controller of the SmartPark is designed in such a way that the active and reactive power transaction with the grid can be controlled independently. Also, the controller limits the current going out of the vehicle during grid faults for batter protection. the real-time modeling is carried out on a Real-Time Digital Simulator (RTDS). Initially, the performance of the controller is studied while being connected to an infinite bus. Also, twelve such parking lot models are integrated to a 12-bus …

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The Missouri Miner, September 16, 2010 Sep 2010

The Missouri Miner, September 16, 2010

The Missouri Miner Newspaper

No abstract provided.

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Faculty Senate Minutes September 16, 2010, Missouri University Of Science And Technology Faculty Senate Sep 2010

Faculty Senate Minutes September 16, 2010, Missouri University Of Science And Technology Faculty Senate

Minutes & Agendas

No abstract provided.

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The Missouri Miner, September 9, 2010 Sep 2010

The Missouri Miner, September 9, 2010

The Missouri Miner Newspaper

No abstract provided.

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The Missouri Miner, September 2, 2010 Sep 2010

The Missouri Miner, September 2, 2010

The Missouri Miner Newspaper

No abstract provided.

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Roger Temam On The Occasion Of His 70th Birthday, Claude Michel Brauner, Danielle Hilhorst, Alain Miranville, Shouhong Wang, Xiaoming Wang Sep 2010

Roger Temam On The Occasion Of His 70th Birthday, Claude Michel Brauner, Danielle Hilhorst, Alain Miranville, Shouhong Wang, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.

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Physics-Based Inductance Extraction For Via Arrays In Parallel Planes For Power Distribution Network Design, Jingook Kim, Liehui Ren, Jun Fan Sep 2010

Physics-Based Inductance Extraction For Via Arrays In Parallel Planes For Power Distribution Network Design, Jingook Kim, Liehui Ren, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

A systematic approach for inductance extraction for via arrays between two parallel planes is presented. Both self and mutual inductance values are obtained based on a cavity model. the physics associated with the via inductances is analyzed, and a rigorous method is developed to derive an equivalent total inductance for multiple via arrays. Analytical equations for the equivalent total inductance are derived in closed forms for simple cases. the proposed method is corroborated with measurements, and application of the method for power distribution network designs is demonstrated. © 2010 IEEE.

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Hamiltonian Theory Based Coordinated Nonlinear Control Of Generator Excitation And Statcoms, Keyou Wang, Mariesa Crow Sep 2010

Hamiltonian Theory Based Coordinated Nonlinear Control Of Generator Excitation And Statcoms, Keyou Wang, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

A coordinated controller for generator excitation and STATCOMs is studied based on the Hamiltonian function method. The Hamiltonian realization structure for multimachine power systems including STATCOMs is developed leading to a proposed coordinated scheme of excitation control and STATCOM control. Simulation results illustrate the effectiveness of the proposed control strategy.

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Adaptive Quadrant Filter Based Phase Locked Loop System, L. Shi, Mariesa Crow Sep 2010

Adaptive Quadrant Filter Based Phase Locked Loop System, L. Shi, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Phase-Locked-Loop (PLL) is one of the key technologies extensively used in grid connected power electronics system. A good PLL system can detect the grid phase angle and frequency fast and accurately, and additionally it can extract the positive sequence (or fundamental component for single phase system) exactly. In real applications, source signal (voltage or current) sensed for PLL usually includes harmonic distortion, unbalanced components, noises and frequency variations. Conventional PLL strategy cannot solve all the problems, especially the unbalanced and harmonic distortion. There is a trade-off between the dynamic response and phase angle tracking accuracy. Different PLL solutions are proposed …

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Uncertainty Quantification Integrated To Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder Sep 2010

Uncertainty Quantification Integrated To Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Point-Collocation Non-intrusive Polynomial Chaos (NIPC) method has been applied to a stochastic synthetic jet actuator problem used as one of the test cases in the CFDVAL2004 workshop to demonstrate the integration of computationally efficient uncertainty quantification to the high-fidelity CFD modeling of synthetic jet actuators. The test case included the simulation of an actuator generating a synthetic jet issued into quiescent air. The Point-Collocation NIPC method is used to quantify the uncertainty in the long-time averaged u and v-velocities at several locations in the flow field due to the uniformly distributed uncertainty introduced in the amplitude and frequency of …

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Efficient Utilization Of Renewable Energy Sources By Gridable Vehicles In Cyber-Physical Energy Systems, Ahmed Yousuf Saber, Ganesh K. Venayagamoorthy Sep 2010

Efficient Utilization Of Renewable Energy Sources By Gridable Vehicles In Cyber-Physical Energy Systems, Ahmed Yousuf Saber, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

The main sources of emission today are from the electric power and transportation sectors. One of the main goals of a cyber-physical energy system (CPES) is the integration of renewable energy sources and grid able vehicles (GVs) to maximize emission reduction. GVs can be used as loads, sources and energy storages in CPES. a large CPES is very complex considering all conventional and green distributed energy resources, dynamic data from sensors, and smart operations (e.g., charging/discharging, control, etc.) from/to the grid to reduce both cost and emission. If large number of GVs are connected to the electric grid randomly, peak …

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A Boundary Corrected Expansion Of The Moments Of Nearest Neighbor Distributions, Elia Liitiäinen, Amaury Lendasse, Francesco Corona Sep 2010

A Boundary Corrected Expansion Of The Moments Of Nearest Neighbor Distributions, Elia Liitiäinen, Amaury Lendasse, Francesco Corona

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Article, the Moments of Nearest Neighbor Distance Distributions Are Examined. While the Asymptotic Form of Such Moments is Well-Known, the Boundary Effect Has This Far Resisted a Rigorous Analysis. Our Goal is to Develop a New Technique that Allows a Closed-Form High Order Expansion, Where the Boundaries Are Taken into Account Up to the First Order. the Resulting Theoretical Predictions Are Tested Via Simulations and Found to Be Much More Accurate Than the First Order Approximation Obtained by Neglecting the Boundaries. While Our Results Are of Theoretical Interest, They Definitely Also Have Important Applications in Statistics and Physics. …

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Nona-Arginine Facilitates Delivery Of Quantum Dots Into Cells Via Multiple Pathways, Yi Xu, Betty Revon Liu, Han Jung Lee, Katie Shannon, Jeffrey G. Winiarz, Tien-Chun Wang, Huey-Jenn Chiang, Yue-Wern Huang Sep 2010

Nona-Arginine Facilitates Delivery Of Quantum Dots Into Cells Via Multiple Pathways, Yi Xu, Betty Revon Liu, Han Jung Lee, Katie Shannon, Jeffrey G. Winiarz, Tien-Chun Wang, Huey-Jenn Chiang, Yue-Wern Huang

Biological Sciences Faculty Research & Creative Works

Semiconductor quantum dots (QDs) have recently been used to deliver and monitor biomolecules, such as drugs and proteins. However, QDs alone have a low efficiency of transport across the plasma membrane. In order to increase the efficiency, we used synthetic nona-arginine (SR9), a cell-penetrating peptide, to facilitate uptake. We found that SR9 increased the cellular uptake of QDs in a noncovalent binding manner between QDs and SR9. Further, we investigated mechanisms of QD/SR9 cellular internalization. Low temperature and metabolic inhibitors markedly inhibited the uptake of QD/SR9, indicating that internalization is an energy-dependent process. Results from both the pathway inhibitors and …

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"Pull-In" Of A Pre-Stressed Thin Film By An Electrostatic Potential: A 1-D Rectangular Bridge And A 2-D Circular Diaphragm, Gang Duan, Kai Tak Wan Sep 2010

"Pull-In" Of A Pre-Stressed Thin Film By An Electrostatic Potential: A 1-D Rectangular Bridge And A 2-D Circular Diaphragm, Gang Duan, Kai Tak Wan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A one-dimensional (1-D) rectangular pre-stressed thin film clamped at two opposite ends is actuated by an electrostatic voltage applied to a pad directly underneath. the pre-stress is allowed to be either tensile or compressive in nature. at a critical applied voltage, the film becomes unstable and makes direct contact with the pad, leading to "pull-in". an elastic model is constructed to account for the phenomenon over ranges of film pad gap and residual stress. the results compare favorably with finite element analysis (FEA) in literature and experimental data and possess distinct advantages over other available closed-form solutions. the model is …

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Characterization Of Soil Water Content Variability And Soil Texture Using Gpr Groundwave Techniques, Katherine R. Grote, Cale T. Anger, Bridget Kelly, Susan Sharpless Hubbard, Yoram N. Rubin Sep 2010

Characterization Of Soil Water Content Variability And Soil Texture Using Gpr Groundwave Techniques, Katherine R. Grote, Cale T. Anger, Bridget Kelly, Susan Sharpless Hubbard, Yoram N. Rubin

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Accurate characterization of near-surface soil water content is vital for guiding agricultural management decisions and for reducing the potential negative environmental impacts of agriculture. Characterizing the near-surface soil water content can be difficult, as this parameter is often both spatially and temporally variable, and obtaining sufficient measurements to describe the heterogeneity can be prohibitively expensive. Understanding the spatial correlation of near-surface soil water content can help optimize data acquisition and improve understanding of the processes controlling soil water content at the field scale. In this study, ground penetrating radar (GPR) methods were used to characterize the spatial correlation of water …

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Sensitivity Of Geoelectrical Measurements To The Presence Of Bacteria In Porous Media, Gamal Z. Abdel Aal, Estella A. Atekwana, Silvia Rossbach, D. Dale Werkema Sep 2010

Sensitivity Of Geoelectrical Measurements To The Presence Of Bacteria In Porous Media, Gamal Z. Abdel Aal, Estella A. Atekwana, Silvia Rossbach, D. Dale Werkema

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We investigated the sensitivity of low-frequency electrical measurements (0.1-1000 Hz) to (1) microbial cell density, (2) live and dead cells, and (3) microbial attachment onto mineral surfaces of clean quartz sands and iron oxide-coated sands. Three strains of Pseudomonas aeruginosa PAO1 (wild type and rhlA and pilA mutant) with different motility and attachment properties were used. Varying concentrations of both live and dead cells of P. aeruginosa wild type in sand columns showed no effect on the real conductivity component (σ′). However, the imaginary conductivity component (σ″) increased linearly with increasing concentrations of live cells in sand columns, whereas minimal …

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First Search For Gravitational Waves From The Youngest Known Neutron Star, J. Abadie, Marco Cavaglia, For Full List Of Authors, See Publisher's Website. Sep 2010

First Search For Gravitational Waves From The Youngest Known Neutron Star, J. Abadie, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present a search for periodic gravitational waves from the neutron star in the supernova remnant Cassiopeia A. The search coherently analyzes data in a 12 day interval taken from the fifth science run of the Laser Interferometer Gravitational-Wave Observatory. It searches gravitational-wave frequencies from 100 to 300 Hz and covers a wide range of first and second frequency derivatives appropriate for the age of the remnant and for different spin-down mechanisms. No gravitational-wave signal was detected. Within the range of search frequencies, we set 95% confidence upper limits of (0.7-1.2) x 10-24 on the intrinsic gravitational-wave strain, (0.4-4) …

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Baryon Acoustic Oscillations In 2d: Modeling Redshift-Space Power Spectrum From Perturbation Theory, Atsushi Taruya, Takahiro Nishimichi, Shun Saito Sep 2010

Baryon Acoustic Oscillations In 2d: Modeling Redshift-Space Power Spectrum From Perturbation Theory, Atsushi Taruya, Takahiro Nishimichi, Shun Saito

Physics Faculty Research & Creative Works

We present an improved prescription for the matter power spectrum in redshift space taking proper account of both nonlinear gravitational clustering and redshift distortion, which are of particular importance for accurately modeling baryon acoustic oscillations (BAOs). Contrary to the models of redshift distortion phenomenologically introduced but frequently used in the literature, the new model includes the corrections arising from the nonlinear coupling between the density and velocity fields associated with two competitive effects of redshift distortion, i.e., Kaiser and Finger-of-God effects. Based on the improved treatment of perturbation theory for gravitational clustering, we compare our model predictions with the monopole …

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Relation Between Transmission And Energy Stored In Random Media With Gain, Ben Payne, Jonathan Andreasen, Hui Cao, Alexey Yamilov Sep 2010

Relation Between Transmission And Energy Stored In Random Media With Gain, Ben Payne, Jonathan Andreasen, Hui Cao, Alexey Yamilov

Physics Faculty Research & Creative Works

In this work, we investigate a possibility of using the ratio between optical transmission, T, and energy stored inside the system, E, as a quantitative measure of the enhanced mesoscopic corrections to diffusive transport of light through a random medium with gain. We obtain an expression for T/E as a function of amplification strength in the diffusive approximation and show that it does not a have tendency to diverge when the threshold for random lasing is approached, as both T and E do. Furthermore, we find that a change in T/E signifies a change in the electric field distribution inside …

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Dynamical (E, 2e) Studies Using Tetrahydrofuran As A Dna Analog, Christopher J. Colyer, Susan M. Bellm, B. Lohmann, G. Friedrich Hanne, Ola A. Al-Hagan, Don H. Madison, Chuangang Ning Sep 2010

Dynamical (E, 2e) Studies Using Tetrahydrofuran As A Dna Analog, Christopher J. Colyer, Susan M. Bellm, B. Lohmann, G. Friedrich Hanne, Ola A. Al-Hagan, Don H. Madison, Chuangang Ning

Physics Faculty Research & Creative Works

Triple differential cross sections for the electron-impact ionization of the outer valence orbital of tetrahydrofuran have been measured using the (e, 2e) technique. The measurements have been performed with coplanar asymmetric kinematics, at an incident electron energy of 250 eV and at an ejected electron energy of 10 eV, over a range of momentum transfers. The experimental results are compared with theoretical calculations carried out using the molecular three-body distorted wave model. The results obtained are important for gaining an understanding of electron driven processes at a molecular level and for modeling energy deposition in living tissue.

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Effect Of An Improved Molecular Potential On Strong-Field Tunneling Ionization Of Molecules, Song-Feng Zhao, Cheng Jin, Anh-Thu Le, C. D. Lin Sep 2010

Effect Of An Improved Molecular Potential On Strong-Field Tunneling Ionization Of Molecules, Song-Feng Zhao, Cheng Jin, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

We study the effect of one-electron model potentials on the tunneling ionization rates of molecules in strong fields. By including electron correlation using the modified Leeuwen-Baerends (LB α) model, the binding energies of outer shells of molecules are significantly improved. However, we show that the tunneling ionization rates from the LB α do not differ much from the earlier calculations [Phys. Rev. A 81, 033423 (2010)], in which the local correlation potential was neglected.

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Self-Imaging Of Molecules From Diffraction Spectra By Laser-Induced Rescattering Electrons, Junliang Xu, Zhangjin Chen, Anh-Thu Le, C. D. Lin Sep 2010

Self-Imaging Of Molecules From Diffraction Spectra By Laser-Induced Rescattering Electrons, Junliang Xu, Zhangjin Chen, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

We study high-energy angle-resolved photoelectron spectra of molecules in strong fields. In an oscillating laser electric field, electrons released earlier in the pulse may return to recollide with the target ion, in a process similar to scattering by laboratory prepared electrons. If midinfrared lasers are used, we show that the images generated by the returning electrons are similar to images observed in typical gas-phase electron diffraction (GED). These spectra can be used to retrieve the positions of atoms in a molecule as in GED. Since infrared laser pulses of durations of a few femtoseconds are already available today, the study …

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Tracing Multiple Scattering Patterns In Absolute (E, 2e) Cross Sections For H₂ And He Over A 4Π Solid Angle, Xueguang Ren, Arne Senftleben, Thomas Pflüger, Alexander Dorn, James Colgan, Michael S. Pindzola, Ola A. Al-Hagan, Don H. Madison, Igor Bray, Dmitry V. Fursa, Joachim Hermann Ullrich Sep 2010

Tracing Multiple Scattering Patterns In Absolute (E, 2e) Cross Sections For H₂ And He Over A 4Π Solid Angle, Xueguang Ren, Arne Senftleben, Thomas Pflüger, Alexander Dorn, James Colgan, Michael S. Pindzola, Ola A. Al-Hagan, Don H. Madison, Igor Bray, Dmitry V. Fursa, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

Absolutely normalized (e,2e) measurements for H2 and He covering the full solid angle of one ejected electron are presented for 16 eV sum energy of both final state continuum electrons. For both targets rich cross-section structures in addition to the binary and recoil lobes are identified and studied as a function of the fixed electron's emission angle and the energy sharing among both electrons. For H2 their behavior is consistent with multiple scattering of the projectile as discussed before. For He the binary and recoil lobes are significantly larger than for H2 and partly cover the multiple …

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