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Your search keyword '"HARMON, K."' showing total 26 results
Start Over Author "HARMON, K." Publication Type Reports
26 results on '"HARMON, K."'

1. A differentiable forward model for the concurrent, multi-peak Bragg coherent x-ray diffraction imaging problem

Author

Maddali, S., Frazer, T. D., Delegan, N., Harmon, K. J., Sullivan, S. E., Allain, M., Cha, W., Dibos, A., Poudyal, I., Kandel, S., Nashed, Y. S. G., Heremans, F. J., You, H., Cao, Y., and Hruszkewycz, S. O.

Subjects
Condensed Matter - Materials Science, Electrical Engineering and Systems Science - Signal Processing, Physics - Computational Physics
Abstract

We present a general analytic approach to spatially resolve the nano-scale lattice distortion field of strained and defected compact crystals with Bragg coherent x-ray diffraction imaging (BCDI). Our approach relies on fitting a differentiable forward model simultaneously to multiple BCDI datasets corresponding to independent Bragg reflections from the same single crystal. It is designed to be faithful to heterogeneities that potentially manifest as phase discontinuities in the coherently diffracted wave, such as lattice dislocations in an imperfect crystal. We retain fidelity to such small features in the reconstruction process through a Fourier transform -based resampling algorithm designed to largely avoid the point spread tendencies of commonly employed interpolation methods. The reconstruction model defined in this manner brings BCDI reconstruction into the scope of explicit optimization driven by automatic differentiation. With results from simulations and experimental diffraction data, we demonstrate significant improvement in the final image quality compared to conventional phase retrieval, enabled by explicitly coupling multiple BCDI datasets into the reconstruction loss function., Comment: 30 pages, 23 figures

Published
2022

2. Initial results from the New Horizons exploration of 2014 MU69, a small Kuiper Belt Object

Author

Stern, S. A., Weaver, H. A., Spencer, J. R., Olkin, C. B., Gladstone, G. R., Grundy, W. M., Moore, J. M., Cruikshank, D. P., Elliott, H. A., McKinnon, W. B., Parker, J. Wm., Verbiscer, A. J., Young, L. A., Aguilar, D. A., Albers, J. M., Andert, T., Andrews, J. P., Bagenal, F., Banks, M. E., Bauer, B. A., Bauman, J. A., Bechtold, K. E., Beddingfield, C. B., Behrooz, N., Beisser, K. B., Benecchi, S. D., Bernardoni, E., Beyer, R. A., Bhaskaran, S., Bierson, C. J., Binzel, R. P., Birath, E. M., Bird, M. K., Boone, D. R., Bowman, A. F., Bray, V. J., Britt, D. T., Brown, L. E., Buckley, M. R., Buie, M. W., Buratti, B. J., Burke, L. M., Bushman, S. S., Carcich, B., Chaikin, A. L., Chavez, C. L., Cheng, A. F., Colwell, E. J., Conard, S. J., Conner, M. P., Conrad, C. A., Cook, J. C., Cooper, S. B., Custodio, O. S., Ore, C. M. Dalle, Deboy, C. C., Dharmavaram, P., Dhingra, R. D., Dunn, G. F., Earle, A. M., Egan, A. F., Eisig, J., El-Maarry, M. R., Engelbrecht, C., Enke, B. L., Ercol, C. J., Fattig, E. D., Ferrell, C. L., Finley, T. J., Firer, J., Fischetti, J., Folkner, W. M., Fosbury, M. N., Fountain, G. H., Freeze, J. M., Gabasova, L., Glaze, L. S., Green, J. L., Griffith, G. A., Guo, Y., Hahn, M., Hals, D. W., Hamilton, D. P., Hamilton, S. A., Hanley, J. J., Harch, A., Harmon, K. A., Hart, H. M., Hayes, J., Hersman, C. B., Hill, M. E., Hill, T. A., Hofgartner, J. D., Holdridge, M. E., Horányi, M., Hosadurga, A., Howard, A. D., Howett, C. J. A., Jaskulek, S. E., Jennings, D. E., Jensen, J. R., Jones, M. R., Kang, H. K., Katz, D. J., Kaufmann, D. E., Kavelaars, J. J., Keane, J. T., Keleher, G. P., Kinczyk, M., Kochte, M. C., Kollmann, P., Krimigis, S. M., Kruizinga, G. L., Kusnierkiewicz, D. Y., Lahr, M. S., Lauer, T. R., Lawrence, G. B., Lee, J. E., Lessac-Chenen, E. J., Linscott, I. R., Lisse, C. M., Lunsford, A. W., Mages, D. M., Mallder, V. A., Martin, N. P., May, B. H., McComas, D. J., McNutt, R. L., Mehoke, Jr. D. S., Mehoke, T. S., Nelson, D. S., Nguyen, H. D., Núñez, J. I., Ocampo, A. C., Owen, W. M., Oxton, G. K., Parker, A. H., Pätzold, M., Pelgrift, J. Y., Pelletier, F. J., Pineau, J. P., Piquette, M. R., Porter, S. B., Protopapa, S., Quirico, E., Redfern, J. A., Regiec, A. L., Reitsema, H. J., Reuter, D. C., Richardson, D. C., Riedel, J. E., Ritterbush, M. A., Robbins, S. J., Rodgers, D. J., Rogers, G. D., Rose, D. M., Rosendall, P. E., Runyon, K. D., Ryschkewitsch, M. G., Saina, M. M., Salinas, M. J., Schenk, P. M., Scherrer, J. R., Schlei, W. R., Schmitt, B., Schultz, D. J., Schurr, D. C., Scipioni, F., Sepan, R. L., Shelton, R. G., Showalter, M. R., Simon, M., Singer, K. N., Stahlheber, E. W., Stanbridge, D. R., Stansberry, J. A., Steffl, A. J., Strobel, D. F., Stothoff, M. M., Stryk, T., Stuart, J. R., Summers, M. E., Tapley, M. B., Taylor, A., Taylor, H. W., Tedford, R. M., Throop, H. B., Turner, L. S., Umurhan, O. M., Van Eck, J., Velez, D., Versteeg, M. H., Vincent, M. A., Webbert, R. W., Weidner, S. E., Weigle II, G. E., Wendel, J. R., White, O. L., Whittenburg, K. E., Williams, B. G., Williams, K. E., Williams, S. P., Winters, H. L., Zangari, A. M., and Zurbuchen, T. H.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The Kuiper Belt is a distant region of the Solar System. On 1 January 2019, the New Horizons spacecraft flew close to (486958) 2014 MU69, a Cold Classical Kuiper Belt Object, a class of objects that have never been heated by the Sun and are therefore well preserved since their formation. Here we describe initial results from these encounter observations. MU69 is a bi-lobed contact binary with a flattened shape, discrete geological units, and noticeable albedo heterogeneity. However, there is little surface color and compositional heterogeneity. No evidence for satellites, ring or dust structures, gas coma, or solar wind interactions was detected. By origin MU69 appears consistent with pebble cloud collapse followed by a low velocity merger of its two lobes., Comment: 43 pages, 8 figure

Published
2020
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