Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “READOUT”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,279 records · Page 71

Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using piezoresponse force microscopy

The interface between LaAlO{sub 3} and TiO{sub 2}-terminated SrTiO{sub 3} can be switched between metastable conductive and insulating states using a conductive atomic force microscope probe. Determination of the nanoscale dimensions has previously required a destructive readout (e.g., local restoration of an insulating state). Here it is shown that high-resolution non-destructive imaging of conductive nanostructures can be achieved using a specific piezoresponse force microscopy (PFM) technique. Images of conductive and insulating nanoscale features are achieved with feature sizes as small as 30 nm. The measured nanowire width from PFM is well correlated with those obtained from nanowire erasure.

36 MATERIALS SCIENCE↗

New experimental approaches to search for neutrino mass

In order to obtain high sensitivity in the study of the neutrino mass it is necessary to design experiments able to optimize all the sensitivity parameters. One of the most promising techniques to achieve this goal is the bolometric technique because of its intrinsic characteristics: high detection efficiency, excellent energy resolution, low intrinsic background and the possibility to study many different compounds. The bolometric technique has already obtained excellent results on the neutrino mass study with Cuoricino. The Cuoricino experiment has also shown that surface contaminations of materials facing the detectors would be the limiting factor for the sensitivity of next generation experiments with bolometers. Mainly for this reason scintillating bolometers have been developed allowing a very efficient discrimination of alpha particles thanks to their double readout. Tests performed on these crystals showed moreover the possibility to discriminate the interacting particles through a pulse shape analysis. This feature is very promising because it allows to reach the same results on the background reduction obtained with the hybrid detectors but without complicating the experimental assembly.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Nonlinear vs. bolometric radiation response and phonon thermal conductance in graphene-superconductor junctions

Graphene is a promising candidate for building fast and ultra-sensitive bolometric detectors due to its weak electron-phonon coupling and low heat capacity. In order to realize a practical graphene-based bolometer, several important issues, including the nature of radiation response, coupling efficiency to the radiation and the thermal conductance need to be carefully studied. Addressing these issues, we present graphene-superconductor junctions as a viable option to achieve efficient and sensitive bolometers, with the superconductor contacts serving as hot electron barriers. For a graphene-superconductor device with highly transparent interfaces, the resistance readout in the presence of radio frequency radiation is dominated by non-linear response. On the other hand, a graphene-superconductor tunnel device shows dominantly bolometric response to radiation. For graphene devices fabricated on SiO{sub 2} substrates, we confirm recent theoretical predictions of T{sup 2} temperature dependence of phonon thermal conductance in the presence of disorder in the graphene channel at low temperatures.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Bimodal wireless sensing with dual-channel wide bandgap heterostructure varactors

A capacitive wireless sensing scheme is developed that utilizes an AlN/GaN-based dual-channel varactor. The dual-channel heterostructure affords two capacitance plateaus within the capacitance-voltage (CV) characteristic, owing to the two parallel two-dimensional electron gases (2DEGs) located at respective AlN/GaN interfaces. The capacitance plateaus are leveraged for the definition of two resonant states of the sensor when implemented in an inductively-coupled resonant LRC network for wireless readout. The physics-based CV model is compared with published experimental results, which serve as a basis for the sensor embodiment. The bimodal resonant sensor is befitting for a broad application space ranging from gas, electrostatic, and piezoelectric sensors to biological and chemical detection.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Stamping single wall nanotubes for circuit quantum electrodynamics

We report on a dry transfer technique for single wall carbon nanotube devices, which allows to embed them in high finesse microwave cavity. We demonstrate the ground state charge readout and a quality factor of about 3000 down to the single photon regime. This technique allows to make devices such as double quantum dots, which could be instrumental for achieving the strong spin photon coupling. It can easily be extended to generic carbon nanotube based microwave devices.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

Full control of quadruple quantum dot circuit charge states in the single electron regime

We report the realization of an array of four tunnel coupled quantum dots in the single electron regime, which is the first required step toward a scalable solid state spin qubit architecture. We achieve an efficient tunability of the system but also find out that the conditions to realize spin blockade readout are not as straightforwardly obtained as for double and triple quantum dot circuits. We use a simple capacitive model of the series quadruple quantum dots circuit to investigate its complex charge state diagrams and are able to find the most suitable configurations for future Pauli spin blockade measurements. We then experimentally realize the corresponding charge states with a good agreement to our model.

36 MATERIALS SCIENCE↗

Preface to Special Topic: Piezoresponse Force Microscopy

Almost two decades beyond the inception of piezoresponse force microscopy (PFM) and the seminal papers by G€uthner and Dransfeld1 and Gruverman et al., the technique has become the prevailing approach for nanoscale functional characterization of polar materials and has been extended to the probing of other electromechanical effects through the advent of electrochemical strain microscopy (ESM). This focus issue celebrates some of the recent advances in the field and offers a wider outlook of polar materials and their overall characterization. In this paper, we cover topics that include discussions of the properties of traditional ferroelectrics, such as lead zirconate titanate (PZT) and lithium niobate, relaxorferroelectrics, as well as more “exotic” ferroelectric oxides such as hafnia, ferroelectric biological matter, and multiferroic materials. Technique-oriented contributions include papers on the coupling of PFM with other characterization methods such as x-ray diffraction (XRD) and superconducting quantum interface device (SQUID), in addition to considerations on the open questions on the electromechanical response in biased scanning probe microscopy (SPM) techniques, including the effects of the laser spot placement on the readout cantilever displacement, the influence of the tip on the creation of the domain shapes, and the impact of ionic and electronic dynamics on the observed nanoscale hysteretic phenomena.

36 MATERIALS SCIENCE↗

Development of intelligent instruments with embedded HTTP servers for control and data acquisition in a cryogenic setup—The hardware, firmware, and software implementation

The power of Ethernet for control and automation technology is being largely understood by the automation industry in recent times. Ethernet with HTTP (Hypertext Transfer Protocol) is one of the most widely accepted communication standards today. Ethernet is best known for being able to control through internet from anywhere in the globe. The Ethernet interface with built-in on-chip embedded servers ensures global connections for crate-less model of control and data acquisition systems which have several advantages over traditional crate-based control architectures for slow applications. This architecture will completely eliminate the use of any extra PLC (Programmable Logic Controller) or similar control hardware in any automation network as the control functions are firmware coded inside intelligent meters itself. Here, we describe the indigenously built project of a cryogenic control system built for linear accelerator at Inter University Accelerator Centre, known as “CADS,” which stands for “Complete Automation of Distribution System.” CADS deals with complete hardware, firmware, and software implementation of the automated linac cryogenic distribution system using many Ethernet based embedded cryogenic instruments developed in-house. Each instrument works as an intelligent meter called device-server which has the control functions and control loops built inside the firmware itself. Dedicated meters with built-in servers were designed out of ARM (Acorn RISC (Reduced Instruction Set Computer) Machine) and ATMEL processors and COTS (Commercially Off-the-Shelf) SMD (Surface Mount Devices) components, with analog sensor front-end and a digital back-end web server implementing remote procedure call over HTTP for digital control and readout functions. At present, 24 instruments which run 58 embedded servers inside, each specific to a particular type of sensor-actuator combination for closed loop operations, are now deployed and distributed across control LAN (Local Area Network). A group of six categories of such instruments have been identified for all cryogenic applications required for linac operation which were designed to build this medium-scale cryogenic automation setup. These devices have special features like remote rebooters, daughter boards for PIDs (Proportional Integral Derivative), etc., to operate them remotely in radiation areas and also have emergency switches by which each device can be taken to emergency mode temporarily. Finally, all the data are monitored, logged, controlled, and analyzed online at a central control room which has a user-friendly control interface developed using LabVIEW{sup ®}. This paper discusses the overall hardware, firmware, software design, and implementation for the cryogenics setup.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

A novel, cost-effective, multi-point Thomson scattering system on the Pegasus Toroidal Experiment (invited)

Here, a novel, cost-effective, multi-point Thomson scattering system has been designed, implemented, and operated on the Pegasus Toroidal Experiment. Leveraging advances in Nd:YAG lasers, high-efficiency volume phase holographic transmission gratings, and increased quantum-efficiency Generation 3 image-intensified charge coupled device (ICCD) cameras, the system provides Thomson spectra at eight spatial locations for a single grating/camera pair. The on-board digitization of the ICCD camera enables easy modular expansion, evidenced by recent extension from 4 to 12 plasma/background spatial location pairs. Stray light is rejected using time-of-flight methods suited to gated ICCDs, and background light is blocked during detector readout by a fast shutter. This –10 3 reduction in background light enables further expansion to up to 24 spatial locations. The implementation now provides single-shot T e (R) for n e > 5 × 10 18 m –3 .

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Determining Confounding Sensitivities In Eddy Current Thin Film Measurements

Determining Confounding Sensitivities In Eddy Current Thin Film Measurements Ethan Gros, Lalita Udpa, Electrical Engineering, Michigan State University, East Lansing MI 48824 James A. Smith, Experiment Analysis, Idaho National Laboratory, Idaho Falls ID 83415 Eddy current (EC) techniques are widely used in industry to measure the thickness of non-conductive films on a metal substrate. This is done using a system whereby a coil carrying a high-frequency alternating current is used to create an alternating magnetic field at the surface of the instrument's probe. When the probe is brought near a conductive surface, the alternating magnetic field will induce ECs in the conductor. The substrate characteristics and the distance of the probe from the substrate (the coating thickness) affect the magnitude of the ECs. The induced currents load the probe coil affecting the terminal impedance of the coil. The measured probe impedance is related to the lift off between coil and conductor as well as conductivity of the test sample. For a known conductivity sample, the probe impedance can be converted into an equivalent film thickness value. The EC measurement can be confounded by a number of measurement parameters. It is the goal of this research to determine which physical properties of the measurement set-up and sample can adversely affect the thickness measurement. The eddy current testing is performed using a commercially available, hand held eddy current probe (ETA3.3H spring loaded eddy probe running at 8 MHz) that comes with a stand to hold the probe. The stand holds the probe and adjusts the probe on the z-axis to help position the probe in the correct area as well as make precise measurements. The signal from the probe is sent to a hand held readout, where the results are recorded directly in terms of liftoff or film thickness. Understanding the effect of certain factors on the measurements of film thickness, will help to evaluate how accurate the ETA3.3H spring loaded eddy probe is at measuring film thickness under varying experimental conditions. This research will study the effects of a number of factors such as i) calibration, ii) conductivity, iii) edge effect, iv) surface finish of base material and v) cable condition and compare with the long term reproducibility of a standard measurement. This work was performed with support from the Department of Energy under the United States National Nuclear Security Administration (NNSA) at the Idaho National Laboratory.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

A 5- μ m pitch charge-coupled device optimized for resonant inelastic soft X-ray scattering

Here, we have developed a charge-coupled device (CCD) with 5 μm × 45 μm pixels on high-resistivity silicon. The fully depleted 200 μm-thick silicon detector is back-illuminated through a 10 nm-thick in situ doped polysilicon window and is thus highly efficient for soft through > 8 keV hard X-rays. The device described here is a 1.5 megapixel CCD with 2496 × 620 pixels. The pixel and camera geometry was optimized for Resonant Inelastic X-ray Scattering (RIXS) and is particularly advantageous for spectrometers with limited arm lengths. In this article, we describe the device architecture, construction and operation, and its performance during tests at the Advance Light Source (ALS) 8.0.1 RIXS beamline. The improved spectroscopic performance, when compared with a current standard commercial camera, is demonstrated with a ~280 eV (C K ) X-ray beam on a graphite sample. Readout noise is typically 3-6 electrons and the point spread function for soft C K X-rays in the 5 μm direction is 4.0 μm ± 0.2 μm. Finally, the measured quantum efficiency of the CCD is greater than 75% in the range from 200 eV to 1 keV.

36 MATERIALS SCIENCE↗

Development of a multi-channel capacitive probe for electric field measurements with fine spatial and high time resolution

A capacitive probe is one of a few diagnostics that is directly sensitive to the plasma potential. Using this diagnostic technique, a Multi-channel Linear Capacitive Probe (MLCP) is developed herein for turbulence measurements. The MLCP has 10 spatial channels and provides 9 points of radial electric field measurements simultaneously with a spatial step of 7 mm. A new readout circuit and a correction technique for low frequency attenuation are also developed to achieve the required spatial and time resolution. A performance test of the MLCP using a reversed field pinch plasma confirms that the MLCP resolves sub-centimeter structures of the equilibrium radial electric field profile and fluctuations up to 680 kHz.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

The dilation aided single–line–of–sight x–ray camera for the National Ignition Facility: Characterization and fielding

Crystal x–ray imaging is commonly used in inertial confinement fusion and laser-plasma interaction applications as it has advantages compared to pinhole imaging, such as higher signal throughput, better achievable spatial resolution, and chromatic selection. Yet, currently used x–ray detectors are only able to obtain a single time resolved image per crystal. The dilation aided single–line–of–sight x–ray camera described here was designed for the National Ignition Facility (NIF) and combines two recent diagnostic developments, the pulse dilation principle used in the dilation x-ray imager and a ns–scale multi-frame camera that uses a hold and readout circuit for each pixel. This enables multiple images to be taken from a single–line–of–sight with high spatial and temporal resolution. Presently, the instrument can record two single–line–of–sight images with spatial and temporal resolution of 35 μm and down to 35 ps, respectively, with a planned upgrade doubling the number of images to four. Here we present the dilation aided single–line–of–sight camera for the NIF, including the x–ray characterization measurements obtained at the COMET laser, as well as the results from the initial timing shot on the NIF.

47 OTHER INSTRUMENTATION↗

Quantum dots with split enhancement gate tunnel barrier control

We introduce a silicon metal-oxide-semiconductor quantum dot architecture based on a single polysilicon gate stack. The elementary structure consists of two enhancement gates separated spatially by a gap, one gate forming a reservoir and the other a quantum dot. We demonstrate, in three devices based on two different versions of this elementary structure, that a wide range of tunnel rates is attainable while maintaining single-electron occupation. A characteristic change in slope of the charge transitions as a function of the reservoir gate voltage, attributed to screening from charges in the reservoir, is observed in all devices, and is expected to play a role in the sizable tuning orthogonality of the split enhancement gate structure. The all-silicon process is expected to minimize strain gradients from electrode thermal mismatch, while the single gate layer should avoid issues related to overlayers (e.g., additional dielectric charge noise) and help improve yield. Finally, reservoir gate control of the tunnel barrier has implications for initialization, manipulation and readout schemes in multi-quantum dot architectures.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

A data acquisition system for HV-CMOS sensor research and development in the upgrade of ATLAS experiment

In the High Luminosity LHC (HL-LHC) upgrade of ATLAS experiment in 2026, the new inner tracker detector will be installed. As a promising candidate for the outer layer of the inner tracker detector, the High Voltage CMOS (HV-CMOS) pixel sensors are being investigated by the ATLAS collaboration. A Front-End LInk eXchange (FELIX) based Data Acquisition (DAQ) system is developed for the R&D of the HV-CMOS sensors. A FELIX card with PCIe interface in the back-end is used to control, monitor, calibrate and read out the front-end electronics. In the front-end, a Xilinx evaluation board ZC706 works as the interface between the back- end and custom boards with HV-CMOS sensors and the readout ASIC. In conclusion, the DAQ system was successfully deployed for the testbeam experiment at CERN. Design of the DAQ system, the tuning of sensors and testbeam results will be described in details.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Mechanical Purcell filters for microwave quantum machines

In circuit quantum electrodynamics, measuring the state of a superconducting qubit introduces a loss channel, which can enhance spontaneous emission through the Purcell effect, thus decreasing the qubit lifetime. This decay can be mitigated by performing the measurement through a Purcell filter, which strongly suppresses signal propagation at the qubit transition frequency. If the filter is also well-matched at the readout cavity frequency, it will protect the qubit from decoherence channels without sacrificing measurement bandwidth. In this work, we propose and analyze design for a mechanical Purcell filter, which we also fabricate and characterize at room temperature. The filter is composed of an array of nanomechanical resonators in thin-film lithium niobate, connected in a ladder topology, with series and parallel resonances arranged to produce a bandpass response. Their modest footprint, steep band edges, and lack of cross talk make these filters an appealing alternative to analogous electromagnetic versions currently used in microwave quantum machines.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

A feasible path for the use of ferromagnetic josephson junctions in quantum circuits: The ferro-transmon

We discuss the capabilities of ferromagnetic (F) Josephson junctions (JJs) in a variety of layouts and configurations. The main goal is to demonstrate the potential of these hybrid JJs to disclose new physics and the possibility to integrate them in superconducting classical and quantum electronics for various applications. The feasible path towards the use of ferromagnetic Josephson junctions in quantum circuits starts from experiments demonstrating macroscopic quantum tunneling in NbN/GdN/NbN junctions with ferro-insulator barriers and with triplet components of the supercurrent, supported by a self-consistent electrodynamic characterization as a function of the barrier thickness. This has inspired further studies on tunnel ferromagnetic junctions with a different layout and promoted the first generation of ferromagnetic Al-based JJs, specifically Al/AlO x /Al/Py/Al. This layout takes advantage of the capability to integrate the ferromagnetic layer in the junction without affecting the quality of the superconducting electrodes and of the tunnel barrier. The high quality of the devices paves the way for the possible implementation of Al tunnel-ferromagnetic JJs in superconducting quantum circuits. These achievements have promoted the notion of a novel type of qubit incorporating ferromagnetic JJs. This qubit is based on a transmon design featuring a tunnel JJ in parallel with a ferromagnetic JJ inside a SQUID loop capacitively coupled to a superconducting readout resonator. In conclusion, the effect of an external RF field on the magnetic switching processes of ferromagnetic JJs has been also investigated.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Air-transfer production method for large-area picosecond photodetectors

We have designed and prototyped the process steps for the batch production of large-area micro-channel-plate photomultipliers (MCPPMT) using the “air-transfer” assembly process developed with single LAPPD TM modules. Results are presented addressing the challenges of designing a robust package that can transmit large numbers of electrical signals for pad or strip readout from inside the vacuum tube and of hermetically sealing the large-perimeter window–body interface. We have also synthesized a photocathode in a large-area low-aspect-ratio volume and have shown that the micro-channel plates recover their functionality after cathode synthesis. These steps inform a design for a multi-module batch facility employing dual nested low-vacuum and ultra-high-vacuum systems in a small-footprint. The facility design provides full access to multiple MCP-PMT modules prior to hermetic pinch-off for leak-checking and real-time photocathode optimization.

47 OTHER INSTRUMENTATION↗