The essence of this invention is a method that couples network architecture using neural implicit representations coupled with a novel parametric motion field to perform limited angle 4D-CT reconstruction of deforming scenes.
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- (-) Photoconductive Semiconductor Switches (PCSS) (9)
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![Diffuse discharge circuit breaker with latching switch](/sites/default/files/styles/scale_exact_400x400_/public/2024-02/Diffuse%20discharge%20circuit%20breaker.png?itok=qWpciEtY)
A thyristor will stay conducting until the current through the device is zero (“current zero”) or perhaps slightly negative. LLNL’s approach is to use the opticondistor (“OTV”) to force this current zero in order to force the device into an “off” state. By combining a light-activated thyristor with an OTV, a noise-immune, high efficiency, high-power switching device can be constructed. The…
![A cross-sectional schematic of a diffused Ga2O3 photoconductive semiconductor switch (PCSS)](/sites/default/files/styles/scale_exact_400x400_/public/2024-02/a%20cross-sectional%20schematic%20of%20a%20diffused%20beta-Ga2O3%20PCSS.png?itok=Z41s0FbO)
The researchers’ approach leverages the concept that dopants have high diffusivities in Ga2O3; the key lies in the selection of the appropriate dopant. This LLNL invention describes two device types that employ this design:
![Samples of optimized diamond switches](/sites/default/files/styles/scale_exact_400x400_/public/2024-01/Samples%20of%20optimized%20diamond%20switches.png?itok=5syzdD0q)
Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength.
Characteristics of the LLNL-developed switch are as follows:
![Custom PCB design of a PCSS Laser Diode Driver](/sites/default/files/styles/scale_exact_400x400_/public/2023-11/PCSS%20Laser%20Diode%20Driver.png?itok=WQ2FNHQF)
LLNL researchers have invented an ultrafast PCSS to drive a high-power laser diode with arbitrary pulse widths. These devices operate by supplying a high voltage (>10 kV) to one side of the switch. A short pulse of light illuminates the semiconductor, instantly turning it from highly resistive to highly conductive.
![multi-spectral nondestructive characterization of in-shell tree nuts](/sites/default/files/styles/scale_exact_400x400_/public/2023-11/multi-spectral%20nondestructive%20characterization%20of%20in-shell%20tree%20nuts.png?itok=-W2LFRIH)
LLNL’s novel technology automates the inspection process by using a scanning system that captures data within the walnut shell without having to open the shell. The system output gives a visual image inside the walnut shell sufficient to evaluate and rate the quality of the walnut. The system uses a camara and radar that can capture data at a rapid rate. This improves speed and reliability…
![solid state streak detector](/sites/default/files/styles/scale_exact_400x400_/public/2023-10/Solid%20State%20Streak%20Detector.png?itok=4t6vjY-r)
The approach is to develop a solid-state X-ray imager based on the architecture of the Silicon Drift Detector (SDD) which uses a series of cathode strips on both sides of a silicon wafer to achieve bulk depletion and electron drift. The invention leverages this SDD functionality to achieve signal stretching of liberated charge carriers from X-Ray photons that converts the time domain into the…
![Schematic of LLNL’s Fast Image Acquisition System](/sites/default/files/styles/scale_exact_400x400_/public/2023-06/Fast%20Image%20Acqusition%20System.png?itok=HFyr-Goi)
LLNL’s novel approach is to use a continuous moving camera with a scan speed of >1 mm/sec and a frame rate of 100 frames per second. The key is to have a light source that flashes with a duration of one nanosecond, thus essentially freezing the image with no blur. Clear images of high resolution can then be captured through a high-magnification objective lens (reflection mode) or through…
![twister oven component with reflective inner cylinder surface](/sites/default/files/styles/scale_exact_400x400_/public/2023-06/twister%20oven%20component.png?itok=v3jlzm2V)
U.S. Patent No. 11,555,965 describes LLNL’s invention of “Illumination Frustums” for photoconductive switches to capture and “frustrate” the light from leaving the frustum. LLNL researcher’s latest novel invention, “Twister Oven”, achieves this by encouraging laser light absorption in a photo conductor material. Light enters the oven twisting and reflecting, making near normal incident multi…
![A photoconductive switch made from a synthetic, chemical vapor deposition diamond under test](/sites/default/files/styles/scale_exact_400x400_/public/2023-06/Photoconductive%20switch.jpg?itok=xC1O7vXg)
Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength. The diamond material is chosen to be doped with substitutional nitrogen to act as a source of electrons. The device architecture allows maximum light entering the aperture. The top and bottom electrodes are made of ultra-wide bandgap (UWBG)…
![3DQ Concept: Use two 2D detectors to enable detection of 3D position for the same event.](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/3DQ%20Concept.png?itok=hPgLZTTl)
LLNL’s approach to the development of a wide-field, three-dimensional quantum (3DQ) microscope is to harness quantum entangled photons to form simultaneous 3D optical images, which could be a new paradigm for 3D volumetric imaging of biological specimens. The 3DQ microscope is comprised of a novel optical system with highly sensitive detectors and an on-demand light source of entangled…
![schematic of LLNL’s field emission photocathode device architecture with examples of tunable SiC surface micro- and nanostructures fabricated at LLNL](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/FE%20photocathode%20device.png?itok=z-1Om9v8)
LLNL researchers faced this challenge by bridging the gap between VEDs and solid-state electronics (SSE). Their approach was to create a hybrid vacuum microelectronic device (VMD) architecture that combines the properties of vacuum as the electronic medium and the compact form factor and manufacturing scalability of semiconductor microelectronic chips.
![Segments of transmission line lengths can be switched to open circuit (as shown) or shorted to the ground (not shown)](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/Segments%20of%20tranmission%20line%20lengths.png?itok=FF0qaBGw)
Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength. The diamond material is specifically doped with substitutional nitrogen, which act as a source of electrons. The device architecture allows maximum light entering the aperture. The top and bottom electrodes are made of ultra wide band gap (UWBG)…
![Annular illumination on photo conductor by Conical Total Internal Reflection “CTIR” endcap](/sites/default/files/styles/scale_exact_400x400_/public/2023-05/CONIFR.png?itok=L4wSanXF)
The approach is to use a custom-designed frustrum and attach it to the optical fiber that connects to the PCSS. Light from the fiber enters the frustrum, spreads out, and enters the PCSS. Any unabsorbed light re-enters the frustrum and, because of its geometry, reflects back into the PCSS itself with only a negligible fraction escaping from the fiber. The shape of the novel frustrum is…
![Schematic of high density detachable electrical interfaces with a single layer](/sites/default/files/styles/scale_exact_400x400_/public/2023-04/High%20density%20detachable%20interface_single.png?itok=HqwlqXwl)
Many of the disadvantages of current interface devices can be overcome with LLNL’s novel interface design, which relies on area array distribution where independent interface connector subassemblies are positioned in a planar grid. Not only is the interface device expandable area-wise (without increasing contact force), but it could also be expanded height-wise, with multiple layers of these…
![Flexible optoelectronic chip with integrated transmitter and receiver subassemblies](/sites/default/files/styles/scale_exact_400x400_/public/2023-04/Flexible_optoelectronic_chip.png?itok=EVf8ujMo)
Commercial fiber optic cables are the current standard for carrying optical signals in industries like communications or medical devices. However, the fibers are made of glass, which do not have favorable characteristics for applications that require flexibility and re-routing, e.g. typically brittle, limited selection of materials, dimension constraints.
![Livermore Tomography Tools LTT](/sites/default/files/styles/scale_exact_400x400_/public/2022-06/LTT.jpg?itok=cQE9Kpef)
To solve these challenges using new and existing CT system designs, LLNL has developed an innovative software package for CT data processing and reconstruction. Livermore Tomography Tools (LTT) is a modern integrated software package that includes all aspects of CT modeling, simulation, reconstruction, and analysis algorithms based on the latest research in the field. LTT contains the most…
![Livermore Tomography Tools LTT](/sites/default/files/styles/scale_exact_400x400_/public/2022-06/LTT.jpg?itok=cQE9Kpef)
LLNL's 3D X-ray imager combines two different hardware pieces. The first is an x-ray optic with a depth-of-field that is small compared to the object under investigation. Reflective Wolter type x-ray optics are one such design. These hollow optics have a relatively large collection efficiency and can be designed with a large field of view. The depth of focus, which is the distance over which a…
![iChip, brain on a chip](/sites/default/files/styles/scale_exact_400x400_/public/2022-07/iChip.jpg?itok=B-rQJQjn)
LLNL has developed a brain-on-a-chip system with a removable cell-seeding funnel to simultaneously localize neurons from various brain regions in an anatomically relevant manner and over specific electrode regions of a MEA. LLNL’s novel, removable cell seeding funnel uses a combination of 3D printing and microfabrication that allows neurons from select brain regions to easily be seeded into…
![Marine helmet](/sites/default/files/styles/scale_exact_400x400_/public/2022-06/Marine%20helmet-inside.jpg?itok=8W_dqpgI)
LLNL's high fidelity hydrocode is capable of predicting blast loads and directly coupling those loads to structures to predict a mechanical response. By combining this code and our expertise in modeling blast-structure interaction and damage, along with our access to experimental data and testing facilities, we can contribute to the design of protective equipment that can better mitigate the…