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Albuquerque, NM, United States

Savukov I.,Los Alamos National Laboratory | Karaulanov T.,Los Alamos National Laboratory | Karaulanov T.,Senior Scientific LLC
Journal of Magnetic Resonance | Year: 2014

Recently, anatomical ultra-low field (ULF) MRI has been demonstrated with an atomic magnetometer (AM). A flux-transformer (FT) has been used for decoupling MRI fields and gradients to avoid their negative effects on AM performance. The field of view (FOV) was limited because of the need to compromise between the size of the FT input coil and MRI sensitivity per voxel. Multi-channel acquisition is a well-known solution to increase FOV without significantly reducing sensitivity. In this paper, we demonstrate twofold FOV increase with the use of three FT input coils. We also show that it is possible to use a single atomic magnetometer and single acquisition channel to acquire three independent MRI signals by applying a frequency-encoding gradient along the direction of the detection array span. The approach can be generalized to more channels and can be critical for imaging applications of non-cryogenic ULF MRI where FOV needs to be large, including head, hand, spine, and whole-body imaging. © 2014 Elsevier Ltd. All rights reserved. Source

Li B.,Sandia National Laboratories | Smilgies D.-M.,Cornell University | Price A.D.,Sandia National Laboratories | Price A.D.,Senior Scientific LLC | And 4 more authors.
ACS Nano | Year: 2014

Metal nanoparticles exhibit unique optical characteristics in visible spectra produced by local surface plasmon resonance (SPR) for a wide range of optical and electronic applications. We report the synthesis of poly(N-isopropylacrylamide) surfactant (PNIPAM-C18)-functionalized metal nanoparticles and ordered superlattice arrays through an interfacial self-Assembly process. The method is simple and reliable without using complex chemistry. The PNIPAM-C18-functionalized metal nanoparticles and ordered superlattices exhibit responsive behavior modulated by external temperature and relative humidity (RH). In situ grazing-incidence small-Angle X-ray scattering studies confirmed that the superlattice structure of PNIPAM-C18 surfactant-functionalized nanoparticle arrays shrink and spring back reversibly based on external thermal and RH conditions, which allow flexible manipulation of interparticle spacing for tunable SPR. PNIPAM-C18 surfactants play a key role in accomplishing this responsive property. The ease of fabrication of the responsive nanostructure facilitates investigation of nanoparticle coupling that depends on interparticle separation for potential applications in chemical and biological sensors as well as energy storage devices. © 2014 American Chemical Society. Source

Karaulanov T.,Los Alamos National Laboratory | Karaulanov T.,Senior Scientific LLC | Savukov I.,Los Alamos National Laboratory | Kim Y.J.,Los Alamos National Laboratory
Measurement Science and Technology | Year: 2016

We constructed a spin-exchange relaxation-free (SERF) magnetometer with a small angle between the pump and probe beams facilitating a multi-channel design with a flat pancake cell. This configuration provides almost complete overlap of the beams in the cell, and prevents the pump beam from entering the probe detection channel. By coupling the lasers in multi-mode fibers, without an optical isolator or field modulation, we demonstrate a sensitivity of 10 f T/√Hz for frequencies between 10 Hz and 100 Hz. In addition to the experimental study of sensitivity, we present a theoretical analysis of SERF magnetometer response to magnetic fields for small-angle and parallel-beam configurations, and show that at optimal DC offset fields the magnetometer response is comparable to that in the orthogonal-beam configuration. Based on the analysis, we also derive fundamental and probe-limited sensitivities for the arbitrary non-orthogonal geometry. The expected practical and fundamental sensitivities are of the same order as those in the orthogonal geometry. We anticipate that our design will be useful for magnetoencephalography (MEG) and magnetocardiography (MCG) applications. © 2016 IOP Publishing Ltd. Source

Senior Scientific LLC | Date: 2016-05-17

Chemical reagents, namely, nanoparticles comprising metals, metal alloys, or both, for non-medical purposes; Diagnostic reagents, namely, nanoparticles comprising metals, metal alloys, or both, for scientific or research use; Reagents, namely, nanoparticles comprising metals, metal alloys, or both, for research purposes; Reagents, namely, nanoparticles comprising metals, metal alloys, or both, for scientific or medical research use.


Senior Scientific LLC | Date: 2014-03-22

Medical imaging apparatus for small animals, in a research laboratory environment.

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