8 research outputs found

    Low field SQUID MRI devices, components and methods

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    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample

    Low Field Squid MRI Devices, Components and Methods

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    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample

    Design considerations for a background limited 350 micron pixel array using lumped element superconducting microresonators

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    Future submillimeter telescopes will demand arrays with ~ 10^6 pixels to fill the focal plane. MAKO is a 350 µm camera being developed to demonstrate the use of superconducting microresonators to meet the high multiplexing factors required for scaling to large-format arrays while offering background-limited single-pixel sensitivity. Candidate pixel designs must simultaneously meet many requirements. To achieve the desired noise equivalent powers it must efficiently absorb radiation, feature a high responsivity, and exhibit low intrinsic device noise. Additionally, the use of high resonator quality factors of order ~ 10^5 and resonant frequencies of order f_(res) ≈ 100 MHz are desirable in order to reduce the per-pixel bandwidth to a minimum set by telescope scan speeds. This allows a maximum number of pixels to be multiplexed in a fixed electronic bandwidth. Here we present measurement results of the first MAKO prototype array which meets these design requirements while demonstrating sufficient sensitivity for background-limited operation at ground-based, far-infrared telescopes

    Circular Kinks on the Surface of Granular Material Rotated in a Tilted Spinning Bucket

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    We find that circular kinks form on the surface of granular material when the axis of rotation is tilted more than the angle of internal friction of the material. Radius of the kinks is measured as a function of the spinning speed and the tilting angle. Stability consideration of the surface results in an explanation that the kink is a boundary between the inner unstable and outer stable regions. A simple cellular automata model also displays kinks at the stability boundary

    MAKO: a pathfinder instrument for on-sky demonstration of low-cost 350 micron imaging arrays

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    Submillimeter cameras now have up to 10^4 pixels (SCUBA 2). The proposed CCAT 25-meter submillimeter telescope will feature a 1 degree field-of-view. Populating the focal plane at 350 microns would require more than 10^6 photon-noise limited pixels. To ultimately achieve this scaling, simple detectors and high-density multiplexing are essential. We are addressing this long-term challenge through the development of frequency-multiplexed superconducting microresonator detector arrays. These arrays use lumped-element, direct-absorption resonators patterned from titanium nitride films. We will discuss our progress toward constructing a scalable 350 micron pathfinder instrument focusing on fabrication simplicity, multiplexing density, and ultimately a low per-pixel cost
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