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Compressed optimization of device architectures

Physical Review Applied

Frees, Adam; Foulk, James W.; Ward, Daniel R.; Blume-Kohout, Robin; Eriksson, M.A.; Friesen, Mark; Coppersmith, S.N.

Recent advances in nanotechnology have enabled researchers to control individual quantum mechanical objects with unprecedented accuracy, opening the door for both quantum and extreme-scale conventional computing applications. As these devices become larger and more complex, the ability to design them such that they can be simply controlled becomes a daunting and computationally infeasible task. Here, motivated by ideas from compressed sensing, we introduce a protocol for the Compressed Optimization of Device Architectures (CODA). It leads naturally to a metric for benchmarking device performance and optimizing device designs, and provides a scheme for automating the control of gate operations and reducing their complexity. Because CODA is computationally efficient, it is readily extensible to large systems. As a result, we demonstrate the CODA benchmarking and optimization protocols through simulations of up to eight quantum dots in devices that are currently being developed experimentally for quantum computation.

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Development and testing of a nitrous-oxide/ethanol bi-propellant rocket engine

AIAA Journal of Propulsion and Power

Grubelich, Mark C.; Foulk, James W.; Hargather, Michael J.; Youngblood, Stewart; Morales, Rudy; Phillip, Jeff

Here, a liquid bi-propellant rocket engine and supporting infrastructure has been de-signed, constructed, and tested at New Mexico Institute of Mining and Technology ina cooperative effort with Sandia National Laboratories. The modular engine designconsists of a head-end fuel-oxidizer injector, gaseous H2/02 torch ignitor, combustionchamber, and nozzle modules. The robust modular design allows for rapid config-uration changes and component replacement if damaged in testing.

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Conceptual design of a 10 13 -W pulsed-power accelerator for megajoule-class dynamic-material-physics experiments

Physical Review Accelerators and Beams

Stygar, William A.; Reisman, David; Stoltzfus, Brian; Austin, Kevin N.; Foulk, James W.; Breden, Eric W.; Cooper, R.A.; Cuneo, Michael E.; Davis, Jean-Paul; Ennis, J.B.; Gard, Paul D.; Greiser, G.W.; Gruner, Frederick R.; Haill, Thomas A.; Hutsel, Brian T.; Jones, Peter; Lechien, K.R.; Leckbee, Joshua; Lucero, Diego; Mckee, G.R.; Moore, James M.; Mulville, Thomas D.; Muron, David J.; Root, Seth; Savage, Mark E.; Sceiford, M.E.; Spielman, R.B.; Waisman, Eduardo M.; Wisher, Matthew L.

In this study, we have developed a conceptual design of a next-generation pulsed-power accelerator that is optmized for driving megajoule-class dynamic-material-physics experiments at pressures as high as 1 TPa. The design is based on an accelerator architecture that is founded on three concepts: single-stage electrical-pulse compression, impedance matching, and transit-time-isolated drive circuits. Since much of the accelerator is water insulated, we refer to this machine as Neptune. The prime power source of Neptune consists of 600 independent impedance-matched Marx generators. As much as 0.8 MJ and 20 MA can be delivered in a 300-ns pulse to a 16-mΩ physics load; hence Neptune is a megajoule-class 20-MA arbitrary waveform generator. Neptune will allow the international scientific community to conduct dynamic equation-of-state, phase-transition, mechanical-property, and other material-physics experiments with a wide variety of well-defined drive-pressure time histories. Because Neptune can deliver on the order of a megajoule to a load, such experiments can be conducted on centimeter-scale samples at terapascal pressures with time histories as long as 1 μs.

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Results 1926–1950 of 2,394
Results 1926–1950 of 2,394