Tabletop Approach Research Articles

Design of a 3000-Pixel Transition-Edge Sensor X-Ray Spectrometer for Microcircuit Tomography.

Feature sizes in integrated circuits have decreased substantially over time, and it has become increasingly difficult to three-dimensionally image these complex circuits after fabrication. This can be important for process development, defect analysis, and detection of unexpected structures in externally sourced chips, among other applications. Here, we report on a non-destructive, tabletop approach that addresses this imaging problem through x-ray tomography, which we uniquely realize with an instrument that combines a scanning electron microscope (SEM) with a transition-edge sensor (TES) x-ray spectrometer. Our approach uses the highly focused SEM electron beam to generate a small x-ray generation region in a carefully designed target layer that is placed over the sample being tested. With the high collection efficiency and resolving power of a TES spectrometer, we can isolate x-rays generated in the target from background and trace their paths through regions of interest in the sample layers, providing information about the various materials along the x-ray paths through their attenuation functions. We have recently demonstrated our approach using a 240 Mo/Cu bilayer TES prototype instrument on a simplified test sample containing features with sizes of ∼ 1 μm. Currently, we are designing and building a 3000 Mo/Au bilayer TES spectrometer upgrade, which is expected to improve the imaging speed by factor of up to 60 through a combination of increased detector number and detector speed.

Concurrent magneto-optical imaging and magneto-transport readout of electrical switching of insulating antiferromagnetic thin films

We demonstrate stable and reversible current induced switching of large-area (>100 μm2) antiferromagnetic domains in NiO/Pt by performing concurrent transport and magneto-optical imaging measurements in an adapted Kerr microscope. By correlating the magnetic images of the antiferromagnetic domain changes and magneto-transport signal response in these current-induced switching experiments, we disentangle magnetic and non-magnetic contributions to the transport signal. Our table-top approach establishes a robust procedure to subtract the non-magnetic contributions in the transport signal and extract the spin-Hall magnetoresistance response associated with the switching of the antiferromagnetic domains, enabling one to deduce details of the antiferromagnetic switching from simple transport measurements.

Laser-induced surface relief nanocrowns as a manifestation of nanoscale Rayleigh-Plateau hydrodynamic instability

Nanoscale hydrodynamic instability of ring-like molten rims around ablative microholes produced in nanometer-thick silver and gold films by tightly focused nanosecond (ns) laser pulses was experimentally explored in terms of laser pulse energy and film thickness. These parametric dependencies of basic instability characteristics - order and period of the resulting nanocrowns - were analyzed, revealing its apparently Rayleigh-Plateau character, as compared to much less consistent possible van der Waals and impact origins. Along with fundamental importance, these findings will put forward ns pulsed laser ablation as an alternative facile inexpensive table-top approach to study such hydrodynamic instabilities developing at ns temporal and nanometer spatial scales as well as to produce unique plasmon-active hierarchical surface morphologies applicable for chemo- and biosensing.

P078: If you build it they will come: use of live actor patients during a hospital-wide mass casualty simulation exercise to garner institutional commitment to long term drills

Introduction: BACKGOUND In the modern era of terrorism and senseless violence, it is essential that hospital staff have expertise in implementation of a mass casualty incident (MCI) plan. OBJECTIVES 1. To assess current gaps in implementation of an academic urban hospital code orange plan using live simulation and tabletop exercise. 2. To identify and educate front-line staff to champion a hospital-wide MCI plan. INNOVATION Historically, in order to limit resource utilization and impact on patient care, disaster response training of front-line staff involved tabletop exercises only. The tenets of experiential learning suggest that learner engagement through realistic active practice of skills achieves deeper uptake of new knowledge. We enhanced the traditional tabletop approach through novel use of live actor patients presenting to an academic, urban emergency department (ED) during a hospital-wide MCI simulation. Methods: To assess the current code orange plan, an interprofessional, committee comprising expert leaders in trauma, emergency preparedness, emergency medicine and simulation integrated tabletop and live simulation to stage a MCI based on a mock incident at a new subway station. ED staff, the trauma team and champions from medicine, surgery and critical care participated along with support departments such as Patient Flow, Patient Transport, Environmental Services and the Hospital Emergency Operations Centre. Ten live actor patients and eight virtual patients presented to the ED. The exercise occurred in situ in the ED. Other participating departments conducted tabletop exercises and received live actor patients. Results: CURRICULUM Staff decanted the ED and other participating units using their current knowledge of hospital code orange policy. Live and virtual patients were triaged and managed according to severity of injuries. Live actor patients were assessed, intervened and transported to their designated unit. Virtual patients were managed through verbal discussion with the simulation controllers. An ED debrief took place using a plus/delta approach followed by a hospital-wide debrief. Conclusion: CONCLUSION An interprofessional hospital-wide MCI simulation revealed important challenges such as communication, command and control and patient-tracking . The exercise ignited enthusiasm and commitment to longitudinal practice and improvement for identified gaps.

Ultrafast electron-lattice coupling dynamics in VO2 and V2O3 thin films

Ultrafast optical pump - optical probe and optical pump - terahertz probe spectroscopy were performed on vanadium dioxide (VO2) and vanadium sesquioxide (V2O3) thin films over a wide temperature range. A comparison of the experimental data from these two different techniques and two different vanadium oxides, in particular a comparison of the electronic oscillations generated by the photoinduced longitudinal acoustic modulation, reveals the strong electron-phonon coupling that exists in the metallic state of both materials. The low energy Drude response of V2O3 appears more susceptible than VO2 to ultrafast strain control. Additionally, our results provide a measurement of the temperature dependence of the sound velocity in both systems, revealing a four- to fivefold increase in VO2 and a three- to fivefold increase in V2O3 across the phase transition. Our data also confirm observations of strong damping and phonon anharmonicity in the metallic phase of VO2, and suggest that a similar phenomenon might be at play in the metallic phase of V2O3. More generally, our simple table-top approach provides relevant and detailed information about dynamical lattice properties of vanadium oxides, opening the way to similar studies in other complex materials.

Tabletop imaging using 266nm femtosecond laser pulses, for characterization of structural evolution in, single molecule, chemical reactions

SynopsisWe have demonstrated a generally applicable tabletop approach utilizing a 266nm femtosecond laser pulse pump, 800nm pulse probe, coupled with Coulomb explosion imaging (CEI). We have investigated two simple chemical reactions in C2H2+ simultaneously: proton transfer and C=C bond-breaking, triggered by multiphoton ionization to excited states. Too and fro proton migration results are in excellent agreement with new ab initio trajectory simulations which predict isomerization timescales and pathways.

Customizing smart environments: A tabletop approach

We would like to thank all the volunteers that participated in the empirical study. Our thanks are also due to the ASIC/Polimedia team for their computer hardware support. This work was partially funded by the Spanish Ministry of Science and Innovation under the National R&D&I Program within the project CreateWorlds (TIN2010-20488). It also received support from a postdoctoral fellowship within the VALi+d Program of the Conselleria d'Educacio, Cultura I Esport (Generalitat Valenciana) awarded to Alejandro Catala (APOSTD/2013/013). The work of Patricia Pons has been supported by the Universitat Politecnica de Valencia under the Beca de Excelencia program, and currently by an FPU fellowship from the Spanish Ministry of Education, Culture and Sports (FPU13/03831).

Tabletop imaging of structural evolutions in chemical reactions demonstrated for the acetylene cation.

The introduction of femto-chemistry has made it a primary goal to follow the nuclear and electronic evolution of a molecule in time and space as it undergoes a chemical reaction. Using Coulomb Explosion Imaging, we have shot the first high-resolution molecular movie of a to and fro isomerization process in the acetylene cation. So far, this kind of phenomenon could only be observed using vacuum ultraviolet light from a free-electron laser. Here we show that 266 nm ultrashort laser pulses are capable of initiating rich dynamics through multiphoton ionization. With our generally applicable tabletop approach that can be used for other small organic molecules, we have investigated two basic chemical reactions simultaneously: proton migration and C=C bond breaking, triggered by multiphoton ionization. The experimental results are in excellent agreement with the timescales and relaxation pathways predicted by new and quantitative ab initio trajectory simulations.

A macro method for measuring economic‐benefit returns on cybersecurity investments: The table top approach

AbstractCritical considerations in engineering today's systems are securing the collection, access, and dissemination of the information they contain. Advanced computing technologies, ubiquitous environments, and sophisticated networks enable globally distributed access to data and information repositories to an uncountable community of consumers. Engineering security into these systems is more challenging and sophisticated than ever before. Along with this, assuring the integrity of highly networked systems requires economic decisions in rapidly changing technology and threat environments. Recognizing that countermeasures effective against cyber intrusions today can be ineffective tomorrow, the systems engineering community needs a rapid and agile way to identify the efficacies of competing countermeasure investment decisions. This paper presents a macroanalytic method for measuring economic‐benefit returns on investments in cybersecurity. The method is called the Table Top Approach. The table top approach is designed to place light demands on the granularity of inputs to evaluate the impacts of cyber intrusion events and the benefits of countermeasure investments. The table top approach derives which investments in a set of competing choices offer the greatest cost‐benefit gains in cyber defense, and why. It finds sets of Pareto efficient cost‐benefit investments, and their economic returns, that capture tangible and intangible advantages of countermeasures that strengthen cybersecurity. ©2012 Wiley Periodicals, Inc. Syst Eng 16

Femtosecond time-resolved photoelectron spectroscopy with a vacuum-ultraviolet photon source based on laser high-order harmonic generation

A laser-based tabletop approach to femtosecond time-resolved photoelectron spectroscopy with photons in the vacuum-ultraviolet (VUV) energy range is described. The femtosecond VUV pulses are produced by high-order harmonic generation (HHG) of an amplified femtosecond Ti:sapphire laser system. Two generations of the same setup and results from photoelectron spectroscopy in the gas phase are discussed. In both generations, a toroidal grating monochromator was used to select one harmonic in the photon energy range of 20-30 eV. The first generation of the setup was used to perform photoelectron spectroscopy in the gas phase to determine the bandwidth of the source. We find that our HHG source has a bandwidth of 140 ± 40 meV. The second and current generation is optimized for femtosecond pump-probe photoelectron spectroscopy with high flux and a small spot size at the sample of the femtosecond probe pulses. The VUV radiation is focused into the interaction region with a toroidal mirror to a spot smaller than 100 × 100 μm(2) and the flux amounts to 10(10) photons/s at the sample at a repetition rate of 1 kHz. The duration of the monochromatized VUV pulses is determined to be 120 fs resulting in an overall pump-probe time resolution of 135 ± 5 fs. We show how this setup can be used to map the transient valence electronic structure in molecular dissociation.

A low-energy table-top approach to AMS

A design for a low-energy table-top approach to accelerator mass spectroscopy (AMS) of 14C and other select nuclides is described. The design consists of an ion source capable of producing high intensity +3 ion beams with low emittance at 5–10 keV/nucleon such as an ECR, a pair of E-B analyzers, a metal foil/vapor charge-exchange cell to produce negative ions, another pair of E-B analyzers, and a low-energy ion detector with optional passive absorber.