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Results for “Apertures”

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.

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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

In-situ gloveport glove leak tester

The invention provides a system for detecting leaks in glovebox gloves, the system having a first seal within a glovebox aperture; a second seal contacting exterior surfaces of a glovebox, wherein the exterior surfaces define a periphery of the aperture; a first fluid supply for circumferentially expanding the first seal against center facing surfaces of the aperture to a first pressure; a second fluid supply for inflating the glove to a second pressure; and a pressure gauge for detecting a pressure decrease of the second pressure. Also provided is an in situ method for detecting leaks in glove box gloves, the method having the steps of applying a radially directed force to inside surfaces of cuffs of the gloves to hermetically seal the gloves from the exterior of the glovebox, thereby establishing a seal; inflating the gloves to a pressure; and monitoring the pressure for any decrease in pressure.

42 ENGINEERING↗
DOE OSTI2020

Electronic connector sealing system

An electronic sealing system for sealing and shielding an electronic connector from detrimental liquid cleaners that are applied with or without pressure. The electronic sealing system includes a U-shaped holder, a gasket frame, a gasket, a top plate, and several fasteners. The U-shaped holder cradles the electronic connector. The gasket frame abuts a top side of the holder and includes an aperture. The gasket engages a portion of the connector via the aperture. The top plate abuts the gasket frame opposite the holder so as to encapsulate the gasket over the aperture and hence over a portion of the electronic connector. The fasteners secure the U-shaped holder, gasket frame, and top plate together so that the electronic connector is secured with the holder and so that a portion of the electronic connector is sealed via the gasket.

42 ENGINEERING↗
DOE OSTI2021

Solar thermochemical reactor and methods of manufacture and use thereof

Disclosed herein is a solar reactor comprising a reactor member; an aperture for receiving solar radiation, the aperture being disposed in a plane on a wall of the reactor member, where the plane is oriented at any angle other than parallel relative to the centerline of the reactor member; a plurality of absorber tubes, wherein the absorber tubes are oriented such that their respective centerlines are at an angle other than 90° relative to the centerline of the reactor member; and wherein the aperture has a hydraulic diameter that is from 0.2 to 4 times a hydraulic diameter of at least one absorber tube in the plurality of absorber tubes; and a reactive material, the reactive material being disposed in the plurality of absorber tubes.

Klausner, James F.↗
DOE OSTI2021

Split structure particle accelerators

A particle accelerator can include a first waveguide portion and a second waveguide portion. The first waveguide portion can include a first plurality of cell portions and a first iris portion that is disposed between two of the first plurality of cell portions. The first iris portion can include a first portion of an aperture such that the aperture is configured to be disposed about a beam axis. The first waveguide portion can further include a first bonding surface. The second waveguide portion can include a second plurality of cell portions and a second iris portion that is disposed between two of the second plurality of cell portions. The second iris portion can include a second portion of the aperture. The second waveguide portion can include a second bonding surface.

Agustsson, Ronald↗
DOE OSTI2022

Solving Critical Problems of the Muon Collider Higgs Factory: Optics, Magnets and their Protection, Detector Backgrounds

A low-energy medium-luminosity Muon Collider (MC) is being studied as a possible Higgs Factory (HF). Electrons from muon decays will deposit more than 300 kW in superconducting magnets of the HF collider ring. This imposes significant challenges to superconducting (SC) magnets used in the MC storage ring (SR) and interaction regions (IR). Magnet designs are proposed which provide high operating gradient and magnetic field in a large aperture to accommodate the large size of muon beams (due to low beta*), as well as a cooling system to intercept the large heat deposition from the showers induced by decay electrons. The distribution of heat deposition in the MC SR lattice elements requires large-aperture magnets in order to accommodate thick high-Z absorbers to protect the SC coils. Based on the developed MARS15 model and intensive simulations, a sophisticated radiation protection system was designed for the collider SR and IR to bring the peak power density in the superconducting coils below the quench limit and reduce the dynamic heat deposition in the cold mass by a factor of 100. The system consists of tight tungsten masks in the magnet interconnect regions and elliptical tungsten liners in the magnet aperture optimized individually for each magnet. These also reduce the background particle fluxes in the collider detector.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Micro-lensed fiber optic plate and methods of forming thereof

A method of forming a micro-lensed fiber optic plate. The method includes obtaining a fiber optic plate that has a plurality of fibers arranged in parallel. A first end of a fiber of the plurality of fibers can have a first numerical aperture. The fiber of the plurality of fibers includes a core material running along a length of the fiber that is circumscribed by a layer of cladding material. The method also includes creating a lensed surface at a second end of the fiber of the plurality of fibers. The second end is opposite the first end. The lensed surface of the fiber of the plurality of fibers can have a second numerical aperture that is different from the first numerical aperture.

Bagwell, Brett↗
DOE OSTI2023

Magnetic self-mating fiber optic connector and fiber optic switch sensor

A system or method for a magnetic self-aligning coupling device for a fiber optic cable. The device includes a first end coupling comprising a first magnet and a second magnet. Both magnets include a mating surface and an annular ring defining an axial aperture. The aperture receives a distal end of a segment of fiber optic cable in a tight fit. The fiber optic cable has an exterior sleeve and a fiber core. The fiber core of the first segment and the second segment of the fiber optic cable are axially aligned by magnetic force in the first and second apertures to create a continuous fiber optic path. A method for detecting a security breach of a door using the self-aligning couplings is also described.

Neidigk, Stephen↗
DOE OSTI2023

Modified split structure particle accelerators

A particle accelerator can include a first waveguide portion and a second waveguide portion. The first waveguide portion can include a first plurality of cell portions and a first iris portion that is disposed between two of the first plurality of cell portions. The first iris portion can include a first portion of an aperture such that the aperture is configured to be disposed about a beam axis. The first waveguide portion can further include a first bonding surface. The second waveguide portion can include a second plurality of cell portions and a second iris portion that is disposed between two of the second plurality of cell portions. The second iris portion can include a second portion of the aperture. The second waveguide portion can include a second bonding surface.

Agustsson, Ronald↗
DOE OSTI2023

Mesh holder for serial crystallography

The invention provides a device for immobilizing and shipping crystals and for data collection via serial crystallography, the device having a first planar substrate defining a first transversely extending aperture, wherein the first substrate has a first laterally facing surface; a second planar substrate defining a second transversely extending aperture coaxial with the first aperture, wherein the second substrate has a second laterally facing surface; a third planar substrate and a fourth planar substrate positioned between the first and second substrates such that the first planar substrate, the second planar substrate, the third planar substrate and the fourth planar substrate are parallel; and a means for reversibly applying axial pressure to the first and second laterally facing surfaces so as to compress the third and fourth substrates together.

Lavens, Alex A.↗
DOE OSTI2023

Modified split structure particle accelerators

A particle accelerator can include a first waveguide portion and a second waveguide portion. The first waveguide portion can include a first plurality of cell portions and a first iris portion that is disposed between two of the first plurality of cell portions. The first iris portion can include a first portion of an aperture such that the aperture is configured to be disposed about a beam axis. The first waveguide portion can further include a first bonding surface. The second waveguide portion can include a second plurality of cell portions and a second iris portion that is disposed between two of the second plurality of cell portions. The second iris portion can include a second portion of the aperture. The second waveguide portion can include a second bonding surface.

Agustsson, Ronald↗
DOE OSTI2024

Magnetic self-mating fiber optic connector and fiber optic switch sensor

A system or method for a magnetic self-aligning coupling device for a fiber optic cable. The device includes a first end coupling comprising a first magnet and a second magnet. Both magnets include a mating surface and an annular ring defining an axial aperture. The aperture receives a distal end of a segment of fiber optic cable in a tight fit. The fiber optic cable has an exterior sleeve and a fiber core. The fiber core of the first segment and the second segment of the fiber optic cable are axially aligned by magnetic force in the first and second apertures to create a continuous fiber optic path. A method for detecting a security breach of a door using the self-aligning couplings is also described.

Neidigk, Stephen↗
DOE OSTI2025

Cooling plate assembly for plasma windows positioned in a beam accelerator system

A beam accelerator system operable to produce a medical isotope, including an ion accelerator that generates an ion beam; a low-pressure chamber; an anode adjacent and fluidly connected to the low-pressure chamber; a plasma window adjacent and fluidly connected to the anode; and a cathode housing adjacent and fluidly connected to the plasma window. The plasma window has a plurality of plates, each plate having an aperture that is aligned with an aperture in one or more adjacent plates to form a plasma channel. One or more plates in the plurality of plates includes a unitary plate having an aperture therein, and one or more cooling channels entering the unitary plate at a first side of the unitary plate and exiting the unitary plate at a second side of the unitary plate. The one or more cooling channels run through a thickness of the unitary plate.

Gribb, Tye↗
DOE OSTI2025

Characterization of Pinhole Collimators for High-Resolution Gamma Imaging of Irradiated Fuel

Post-irradiation examination (PIE) of nuclear fuels requires imaging tools capable of resolving isotopic and spatial features with high throughput. This project contributes to a proof-of-concept effort aimed at advancing gamma emission tomography (GET) by evaluating novel fine-aperture pinhole collimators. Two Rose’s metal collimators, 100 µm (20° acceptance angle) and 350 µm (30° acceptance angle), were prototyped and characterized for their effectiveness in transporting gamma rays through the pinhole aperture. To support data collection, a Python-based data acquisition system was developed to coordinate a rotation stage, linear stage, and CZT detector, reducing latency in high-rate gamma event logging to one second per acquisition. Queue-based file writing enabled seamless real-time data capture for count rates up to 35,000 counts per second (cps). List-mode parsing algorithms were implemented to differentiate single and simultaneous gamma interactions for future tomographic reconstruction. Detector response was evaluated in both spectroscopy and list mode acquisition methods across varying source distances to confirm absolute and collimator efficiencies. Preliminary efficiency figures suggest effective collimation of gamma-rays with energies below 700 keV, with ~4% residual intensity through the aperture for Cs-137. The impact of collimator geometry on image quality is currently being evaluated. This groundwork supports the ongoing development of a sub mm resolution cone-beam CT system for imaging fuel phantoms, an essential step toward improving GET efficiency and accelerating nuclear fuel qualification efforts.

46 - INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AN↗
DOE OSTI2020

Multibeam Electron Diffraction

One of the primary uses for transmission electron microscopy (TEM) is to measure diffraction pattern images in order to determine a crystal structure and orientation. In nanobeam electron diffraction (NBED), we scan a moderately converged electron probe over the sample to acquire thousands or even millions of sequential diffraction images, a technique that is especially appropriate for polycrystalline samples. However, due to the large Ewald sphere of TEM, excitation of Bragg peaks can be extremely sensitive to sample tilt, varying strongly for even a few degrees of sample tilt for crystalline samples. In this paper, we present multibeam electron diffraction (MBED), where multiple probe-forming apertures are used to create multiple scanning transmission electron microscopy (STEM) probes, all of which interact with the sample simultaneously. We detail designs for MBED experiments, and a method for using a focused ion beam to produce MBED apertures. We show the efficacy of the MBED technique for crystalline orientation mapping using both simulations and proof-of-principle experiments. We also show how the angular information in MBED can be used to perform 3D tomographic reconstruction of samples without needing to tilt or scan the sample multiple times. Finally, we also discuss future opportunities for the MBED method.

47 OTHER INSTRUMENTATION↗
DOE OSTI2024

Maximizing the Radar Generalized Image Quality Equation for Bistatic SAR Using Waveform Frequency Agility

The radar generalized image quality equation (RGIQE) is a metric used to measure both monostatic and bistatic synthetic aperture radar (BSAR) image quality, it is a function of signal-to-noise ratio (SNR) and 2-D bandwidth. The 2-D bandwidth is equal to the area of the transfer function’s (TF) passband region. With the exception of side-looking monostatic geometries, almost all monostatic and bistatic geometries have skewed passband shapes when waveform frequency parameters remain unchanged from pulse to pulse. Most synthetic aperture radar (SAR) applications require a rectangular-shaped passband region, this is achieved by inscribing a rectangular region within the skewed intrinsic passband region. Increasing skewness results in less inscription area reducing 2-D bandwidth, image SNR, and thus RGIQE capacity. In this article, a waveform with frequency agility is used to rectify the skewness that degrades RGIQE capacity. By changing the waveform’s center frequency and instantaneous bandwidth from pulse to pulse in a particular manner, the intrinsic passband region can be de-skewed. The de-skewed shape maximizes the inscription area thus maximizing 2-D bandwidth, image SNR, and RGIQE capacity. Here, three examples are given in this article, one monostatic geometry, and two bistatic geometries. RGIQE capacity is increased by 52.02%, 44.42%, and 79.09% for the three examples.

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

Utah FORGE: Phase 3 InSAR Study Results

Ground movement is evaluated through analysis of Interferometric Synthetic Aperture Radar (InSAR) interferograms. Results indicate there has been no detectable ground movement at millimeter scale. The zipped file in this submission contains a report, maps, and results from the InSAR Phase 3 study done to determine ground crustal deformation, if any, in the Utah FORGE area. The data used to facilitate this study included synthetic aperture radar data acquired by the TerraSAR-X and TanDEM-X satellite missions operated by the German Space Agency (DLR). It is accompanied by a README.txt file which further describes each included dataset.

15 GEOTHERMAL ENERGY↗
DOE OSTI2020

Exoplanet Sciences with Nulling Interferometers and a Single-mode Fiber-fed Spectrograph

Understanding the atmospheres of exoplanets is a milestone to decipher their formation history and potential habitability. High-contrast imaging and spectroscopy of exoplanets is the major pathway toward the goal. Direct imaging of an exoplanet requires high spatial resolution. Interferometry has proven to be an effective way of improving spatial resolution. However, means of combining interferometry, high-contrast imaging, and high-resolution spectroscopy have been rarely explored. To fill in the gap, we present the dual-aperture fiber nuller (FN) for current-generation 8–10 m telescopes, which provides the necessary spatial and spectral resolution to (1) conduct follow-up spectroscopy of known exoplanets and (2) detect planets in debris-disk systems. The concept of feeding an FN to a high-resolution spectrograph can also be used for future space and ground-based missions. We present a case study of using the dual-aperture FN to search for biosignatures in rocky planets around M stars for a future space interferometry mission. Moreover, we discuss how an FN can be equipped on future extremely large telescopes by using the Giant Magellan Telescope as an example.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2025

Influence of Photoemission Geometry on Timing and Efficiency in 4D Ultrafast Electron Microscopy

Broader adoption of 4D ultrafast electron microscopy (UEM) for the study of chemical, materials, and quantum systems is being driven by development of new instruments as well as continuous improvement and characterization of existing technologies. Perhaps owing to the still-high barrier to entry, the full range of capabilities of laser-driven 4D UEM instruments has yet to be established, particularly when operated at extremely low beam currents (~fA). Accordingly, with an eye on beam stability, we have conducted particle tracing simulations of unconventional off-axis photoemission geometries in a UEM equipped with a thermionic-emission gun. Specifically, we have explored the impact of experimentally adjustable parameters on the time-of-flight (TOF), the collection efficiency (CE), and the temporal width of ultrashort photoelectron packets. The adjustable parameters include the Wehnelt aperture diameter (DW), the cathode set-back position (Ztip), and the position of the femtosecond laser on the Wehnelt aperture surface relative to the optic axis (Rphoto). Notable findings include significant sensitivity of TOF to DW and Ztip, as well as non-intuitive responses of CE and temporal width to varying Rphoto. As a means to improve accessibility, practical implications and recommendations are emphasized wherever possible.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗