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4,582 results on '"Watkins, J"'

1. Stratospheric aerosol source inversion: Noise, variability, and uncertainty quantification

Author

Hart, J., Manickam, I., Gulian, M., Swiler, L., Bull, D., Ehrmann, T., Brown, H., Wagman, B., and Watkins, J.

Subjects
Computer Science - Machine Learning, Physics - Atmospheric and Oceanic Physics, Statistics - Applications
Abstract

Stratospheric aerosols play an important role in the earth system and can affect the climate on timescales of months to years. However, estimating the characteristics of partially observed aerosol injections, such as those from volcanic eruptions, is fraught with uncertainties. This article presents a framework for stratospheric aerosol source inversion which accounts for background aerosol noise and earth system internal variability via a Bayesian approximation error approach. We leverage specially designed earth system model simulations using the Energy Exascale Earth System Model (E3SM). A comprehensive framework for data generation, data processing, dimension reduction, operator learning, and Bayesian inversion is presented where each component of the framework is designed to address particular challenges in stratospheric modeling on the global scale. We present numerical results using synthesized observational data to rigorously assess the ability of our approach to estimate aerosol sources and associate uncertainty with those estimates.

Published
2024

2. Broadening of the Divertor Heat Flux Profile in High Confinement Tokamak Fusion Plasmas with Edge Pedestals Limited by Turbulence in DIII-D

Author

Ernst, D. R., Bortolon, A., Chang, C. S., Ku, S., Scotti, F., Wang, H. Q., Yan, Z., Chen, Jie, Chrystal, C., Glass, F., Haskey, S., Hood, R., Khabanov, F., Laggner, F., Lasnier, C., McKee, G. R., Rhodes, T. L., Truong, D., and Watkins, J.

Subjects
Physics - Plasma Physics
Abstract

Multi-machine empirical scaling predicts an extremely narrow heat exhaust layer in future high magnetic field tokamaks, producing high power densities that require mitigation. In the experiments presented, the width of this exhaust layer is nearly doubled using actuators to increase turbulent transport in the plasma edge. This is achieved in low collisionality, high confinement edge pedestals with their gradients limited by turbulent transport instead of large-scale, coherent instabilities. The exhaust heat flux profile width and divertor leg diffusive spreading both double as a high frequency band of turbulent fluctuations propagating in the electron diamagnetic direction doubles in amplitude. The results are quantitatively reproduced in electromagnetic XGC particle-in-cell simulations which show the heat flux carried by electrons emerges to broaden the heat flux profile, directly supported by Langmuir probe measurements., Comment: 8 pages, 11 figures

Published
2024
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4. Search for Two-neutrino Double-Beta Decay of $^{136}\rm Xe$ to the $0^+_1$ excited state of $^{136}\rm Ba$ with the Complete EXO-200 Dataset

Author

Collaboration, EXO-200, Kharusi, S. Al, Anton, G., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Breidenbach, M., Brunner, T., Cao, G. F., Cen, W. R., Chambers, C., Cleveland, B., Coon, M., Craycraft, A., Daniels, T., Darroch, L., Daugherty, S. J., Davis, J., Delaquis, S., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Dolgolenko, A., Dolinski, M. J., Echevers, J., Fairbank Jr., W., Fairbank, D., Farine, J., Feyzbakhsh, S., Fierlinger, P., Fu, Y. S., Fudenberg, D., Gautam, P., Gornea, R., Gratta, G., Hall, C., Hansen, E. V., Hoessl, J., Hufschmidt, P., Hughes, M., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Johnson, A., Karelin, A., Kaufman, L. J., Koffas, T., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Lenardo, B. G., Leonard, D. S., Li, G. S., Li, S., Li, Z., Licciardi, C., Lin, Y. H., MacLellan, R., McElroy, T., Michel, T., Mong, B., Moore, D. C., Murray, K., Njoya, O., Nusair, O., Odian, A., Ostrovskiy, I., Perna, A., Piepke, A., Pocar, A., Retière, F., Robinson, A. L., Rowson, P. C., Runge, J., Schmidt, S., Sinclair, D., Skarpaas, K., Soma, A. K., Stekhanov, V., Tarka, M., Thibado, S., Todd, J., Tolba, T., Totev, T. I., Tsang, R., Veenstra, B., Veeraraghavan, V., Vogel, P., Vuilleumier, J. -L., Wagenpfeil, M., Watkins, J., Weber, M., Wen, L. J., Wichoski, U., Wrede, G., Wu, S. X., Xia, Q., Yahne, D. R., Yang, L., Yen, Y. -R., Zeldovich, O. Ya., and Ziegler, T.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

A new search for two-neutrino double-beta ($2\nu\beta\beta$) decay of $^{136}\rm Xe$ to the $0^+_1$ excited state of $^{136}\rm Ba$ is performed with the full EXO-200 dataset. A deep learning-based convolutional neural network is used to discriminate signal from background events. Signal detection efficiency is increased relative to previous searches by EXO-200 by more than a factor of two. With the addition of the Phase II dataset taken with an upgraded detector, the median 90$\%$ confidence level half-life sensitivity of $2\nu\beta\beta$ decay to the $0^+_1$ state of $^{136}\rm Ba$ is $2.9 \times 10^{24}~\rm yr$ using a total $^{136}\rm Xe$ exposure of $234.1~\rm kg~yr$. No statistically significant evidence for $2\nu\beta\beta$ decay to the $0^+_1$ state is observed, leading to a lower limit of $T^{2\nu}_{1/2}(0^+ \rightarrow 0^+_1) > 1.4\times10^{24}~\rm yr$ at 90$\%$ confidence level, improved by 70$\%$ relative to the current world's best constraint., Comment: 9 pages, 7 figures, 2 tables

Published
2023
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5. Search for MeV Electron Recoils from Dark Matter in EXO-200

Author

Collaboration, EXO-200, Kharusi, S. Al, Anton, G., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Breidenbach, M., Brunner, T., Cao, G. F., Cen, W. R., Chambers, C., Cleveland, B., Coon, M., Craycraft, A., Daniels, T., Darroch, L., Daugherty, S. J., Davis, J., Delaquis, S., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Dolgolenko, A., Dolinski, M. J., Echevers, J., Fairbank Jr., W., Fairbank, D., Farine, J., Feyzbakhsh, S., Fierlinger, P., Fu, Y. S., Fudenberg, D., Gautam, P., Gornea, R., Gratta, G., Hall, C., Hansen, E. V., Hoessl, J., Hufschmidt, P., Hughes, M., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Johnson, A., Karelin, A., Kaufman, L. J., Koffas, T., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Lenardo, B. G., Leonard, D. S., Li, G. S., Li, S., Li, Z., Licciardi, C., Lin, Y. H., MacLellan, R., McElroy, T., Michel, T., Mong, B., Moore, D. C., Murray, K., Njoya, O., Nusair, O., Odian, A., Ostrovskiy, I., Perna, A., Piepke, A., Pocar, A., Retière, F., Robinson, A. L., Rowson, P. C., Ruddell, D., Runge, J., Schmidt, S., Sinclair, D., Skarpaas, K., Soma, A. K., Stekhanov, V., Tarka, M., Thibado, S., Todd, J., Tolba, T., Totev, T. I., Tsang, R. H. M., Veenstra, B., Veeraraghavan, V., Vogel, P., Vuilleumier, J. -L., Wagenpfeil, M., Watkins, J., Wen, L. J., Wichoski, U., Wrede, G., Wu, S. X., Xia, Q., Yahne, D. R., Yang, L., Yen, Y. -R., Zeldovich, O. Ya., and Ziegler, T.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We present a search for electron-recoil signatures from the charged-current absorption of fermionic dark matter using the EXO-200 detector. We report an average electron recoil background rate of $6.8 \times 10^{-4}\, \mathrm{cts}\,\mathrm{kg}^{-1}\mathrm{yr}^{-1}\mathrm{keV}^{-1}$ above $4\,\mathrm{MeV}$ and find no statistically significant excess over our background projection. Using a total ${}^{136}\mathrm{Xe}$ exposure of $234.1\,\mathrm{kg}\,\mathrm{yr}$ we exclude new parameter space for the charged-current absorption cross-section for dark matter masses between $m_\chi = 2.6\,\mathrm{MeV} - 11.6\,\mathrm{MeV}$ with a minimum of $6\times 10^{-51}\,\mathrm{cm}^2$ at $8.3\,\mathrm{MeV}$ at the $90\%$ confidence level., Comment: 9 pages, 6 figures, 1 table

Published
2022
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7. Search for Majoron-emitting modes of $^{136}$Xe double beta decay with the complete EXO-200 dataset

Author

Kharusi, S. Al, Anton, G., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Breidenbach, M., Brunner, T., Cao, G. F., Cen, W. R., Chambers, C., Cleveland, B., Coon, M., Craycraft, A., Daniels, T., Darroch, L., Daugherty, S. J., Davis, J., Delaquis, S., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Dolgolenko, A., Dolinski, M. J., Echevers, J., Fairbank Jr., W., Fairbank, D., Farine, J., Feyzbakhsh, S., Fierlinger, P., Fudenberg, D., Gautam, P., Gornea, R., Gratta, G., Hall, C., Hansen, E. V., Hoessl, J., Hufschmidt, P., Hughes, M., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Johnson, A., Karelin, A., Kaufman, L. J., Koffas, T., Krucken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Lenardo, B. G., Leonard, D. S., Li, G. S., Li, S., Li, Z., Licciardi, C., Lin, Y. H., MacLellan, R., McElroy, T., Michel, T., Mong, B., Moore, D. C., Murray, K., Njoya, O., Nusair, O., Odian, A., Ostrovskiy, I., Perna, A., Piepke, A., Pocar, A., Retiere, F., Robinson, A. L., Rowson, P. C., Rudde, D., Runge, J., Schmidt, S., Sinclair, D., Skarpaas, K., Soma, A. K., Stekhanov, V., Tarka, M., Thibado, S., Todd, J., Tolba, T., Totev, T. I., Tsang, R., Veenstra, B., Veeraraghavan, V., Vogel, P., Vuilleumier, J. -L., Wagenpfeil, M., Watkins, J., Weber, M., Wen, L. J., Wichoski, U., Wrede, G., Wu, S. X., Xia, Q., Yahne, D. R., Yang, L., Yen, Y. -R., Zeldovich, O. Ya., and Ziegler, T.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

A search for Majoron-emitting modes of the neutrinoless double-beta decay of $^{136}$Xe is performed with the full EXO-200 dataset. This dataset consists of a total $^{136}$Xe exposure of 234.1 kg$\cdot$yr, and includes data with detector upgrades that have improved the energy threshold relative to previous searches. A lower limit of T$_{1/2}^{\rm{^{136}Xe}}>$4.3$\cdot$10$^{24}$ yr at 90\% C.L. on the half-life of the spectral index $n=1$ Majoron decay was obtained, a factor of 3.6 more stringent than the previous limit from EXO-200, corresponding to a constraint on the Majoron-neutrino coupling constant of $|\langle g_{ee}^{M}\rangle|$$<(0.4$-$0.9)\cdot10^{-5}$. The lower threshold and the additional data taken resulted in a factor 8.4 improvement for the $n=7$ mode compared to the previous EXO search. This search provides the most stringent limits to-date on the Majoron-emitting decays of $^{136}$Xe with spectral indices $n=1,2,3,$ and 7.

Published
2021
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8. The EXO-200 detector, part II: Auxiliary Systems

Author

Ackerman, N., Albert, J., Auger, M., Auty, D. J., Badhrees, I., Barbeau, P. S., Bartoszek, L., Baussan, E., Belov, V., Benitez-Medina, C., Bhatta, T., Breidenbach, M., Brunner, T., Cao, G. F., Cen, W. R., Chambers, C., Cleveland, B., Conley, R., Cook, S., Coon, M., Craddock, W., Craycraft, A., Cree, W., Daniels, T., Darroch, L., Daugherty, S. J., Daughhetee, J., Davis, C. G., Davis, J., Delaquis, S., Der Mesrobian-Kabakian, A., deVoe, R., Didberidze, T., Dilling, J., Dobi, A., Dolgolenko, A. G., Dolinski, M. J., Dunford, M., Echevers, J., Espic, L., Fairbank Jr., W., Fairbank, D., Farine, J., Feldmeier, W., Feyzbakhsh, S., Fierlinger, P., Fouts, K., Franco, D., Freytag, D., Fudenberg, D., Gautam, P., Giroux, G., Gornea, R., Graham, K., Gratta, G., Hagemann, C., Hall, C., Hall, K., Haller, G., Hansen, E. V., Hargrove, C., Herbst, R., Herrin, S., Hodgson, J., Hughes, M., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Johnson, A., Johnson, T. N., Johnston, S., Karelin, A., Kaufman, L. J., Killick, R., Koffas, T., Kravitz, S., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Leonard, D. S., Leonard, F., LePort, F., Li, G. S., Li, S., Li, Z., Licciardi, C., Lin, Y. H., Mackay, D., MacLellan, R., Marino, M., Martin, J. -M., Martin, Y., McElroy, T., McFarlane, K., Michel, T., Mong, B., Moore, D. C., Murray, K., Neilson, R., Njoya, O., Nusair, O., O'Sullivan, K., Odian, A., Ostrovskiy, I., Ouellet, C., Piepke, A., Pocar, A., Prescott, C. Y., Pushkin, K., Retiere, F., Rivas, A., Robinson, A. L., Rollin, E., Rowson, P. C., Rozo, M. P., Runge, J., Russell, J. J., Schmidt, S., Schubert, A., Sinclair, D., Skarpaas, K., Slutsky, S., Smith, E., Soma, A. K., Stekhanov, V., Strickland, V., Swift, M., Tarka, M., Todd, J., Tolba, T., Tosi, D., Totev, T. I., Tsang, R., Twelker, K., Veenstra, B., Veeraraghavan, V., Vuilleumier, J. -L., Vuilleumier, J. -M., Wagenpfeil, M., Waite, A., Walton, J., Walton, T., Wamba, K., Watkins, J., Weber, M., Wen, L. J., Wichoski, U., Wittgen, M., Wodin, J., Wood, J., Wrede, G., Wu, S. X., Xia, Q., Yang, L., Yen, Y. -R., Zeldovich, O. Ya, and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract

The EXO-200 experiment searched for neutrinoless double-beta decay of $^{136}$Xe with a single-phase liquid xenon detector. It used an active mass of 110 kg of 80.6%-enriched liquid xenon in an ultra-low background time projection chamber with ionization and scintillation detection and readout. This paper describes the design and performance of the various support systems necessary for detector operation, including cryogenics, xenon handling, and controls. Novel features of the system were driven by the need to protect the thin-walled detector chamber containing the liquid xenon, to achieve high chemical purity of the Xe, and to maintain thermal uniformity across the detector., Comment: Manuscript updated in response to JINST reviewer comments

Published
2021
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9. INGRID: an interactive grid generator for 2D edge plasma modeling

Author

Garcia, B. M., Umansky, M. V., Watkins, J., Guterl, J., and Izacard, O.

Subjects
Physics - Plasma Physics, Physics - Computational Physics, 65L50 (Primary), 65Z05, 65D18 (Secondary)
Abstract

A fusion boundary-plasma domain is defined by axisymmetric magnetic surfaces where the geometry is often complicated by the presence of one or more X-points; and modeling boundary plasmas usually relies on computational grids that account for the magnetic field geometry. The new grid generator INGRID (Interactive Grid Generator) presented here is a Python-based code for calculating grids for fusion boundary plasma modeling, for a variety of configurations with one or two X-points in the domain. Based on a given geometry of the magnetic field, INGRID first calculates a skeleton grid which consists of a small number of quadrilateral patches; then it puts a subgrid on each of the patches, and joins them in a global grid. This domain partitioning strategy makes possible a uniform treatment of various configurations with one or two X-points in the domain. This includes single-null, double-null, and other configurations with two X-points in the domain. The INGRID design allows generating grids either interactively, via a parameter-file driven GUI, or using a non-interactive script-controlled workflow. Results of testing demonstrate that INGRID is a flexible, robust, and user-friendly grid-generation tool for fusion boundary-plasma modeling., Comment: 39 pages, 14 figures

Published
2021
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10. Observation of quasi-coherent density fluctuation in scrape-off layer enhancing boundary transport in high-betaN hybrid plasmas on DIII-D

Author

Hong, R., Rhodes, T. L., Li, Z. Y., Wang, H., Zeng, L., Barada, K., Wang, G., Watkins, J. G., and Peebles, W. A.

Subjects
Physics - Plasma Physics
Abstract

We report the observation of a quasi-coherent density fluctuation (QCF) by the Doppler backscattering system in the scrape-off layer (SOL) region of the DIII-D tokamak. This QCF is observed in high-power, high-performance hybrid plasmas with near double-null divertor (DND) shape during the electron cyclotron heating period. This mode is correlated with a steepened SOL density profile and leads to significantly elevated particle and heat fluxes between ELMs. The SOL QCF is a long-wavelength ion-scale fluctuation and propagates in the ion diamagnetic direction in the plasma frame. Its radial expanse is about 1.5-2 cm, well beyond the typical width of heat flux on DIII-D. Also, the SOL QCF does not show any clear dependence on the effective SOL collisionality and thus may raise issues on the control of plasma-material interactions in low collisionality plasmas in which the blob-induced transport is reduced. A linear simulation using BOUT++ with a 5-field reduced model is performed and compared with experimental observations. In simulation results, an interchange-like density perturbation can be driven by the SOL density gradient, and its peak location and the radial width of the density perturbation are in agreement with the experimental observations.

Published
2020
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11. Search for Majoron-emitting modes of Xe136 double beta decay with the complete EXO-200 dataset

Author

Al Kharusi, S, Anton, G, Badhrees, I, Barbeau, PS, Beck, D, Belov, V, Bhatta, T, Breidenbach, M, Brunner, T, Cao, GF, Cen, WR, Chambers, C, Cleveland, B, Coon, M, Craycraft, A, Daniels, T, Darroch, L, Daugherty, SJ, Davis, J, Delaquis, S, Der Mesrobian-Kabakian, A, DeVoe, R, Dilling, J, Dolgolenko, A, Dolinski, MJ, Echevers, J, Fairbank, W, Fairbank, D, Farine, J, Feyzbakhsh, S, Fierlinger, P, Fudenberg, D, Gautam, P, Gornea, R, Gratta, G, Hall, C, Hansen, EV, Hoessl, J, Hufschmidt, P, Hughes, M, Iverson, A, Jamil, A, Jessiman, C, Jewell, MJ, Johnson, A, Karelin, A, Kaufman, LJ, Koffas, T, Krücken, R, Kuchenkov, A, Kumar, KS, Lan, Y, Larson, A, Lenardo, BG, Leonard, DS, Li, GS, Li, S, Li, Z, Licciardi, C, Lin, YH, MacLellan, R, McElroy, T, Michel, T, Mong, B, Moore, DC, Murray, K, Njoya, O, Nusair, O, Odian, A, Ostrovskiy, I, Perna, A, Piepke, A, Pocar, A, Retière, F, Robinson, AL, Rowson, PC, Ruddell, D, Runge, J, Schmidt, S, Sinclair, D, Skarpaas, K, Soma, AK, Stekhanov, V, Tarka, M, Thibado, S, Todd, J, Tolba, T, Totev, TI, Tsang, R, Veenstra, B, Veeraraghavan, V, Vogel, P, Vuilleumier, J-L, Wagenpfeil, M, Watkins, J, Weber, M, Wen, LJ, Wichoski, U, Wrede, G, and Wu, SX

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences
Abstract

A search for Majoron-emitting modes of the neutrinoless double beta decay of Xe136 is performed with the full EXO-200 dataset. This dataset consists of a total Xe136 exposure of 234.1 kg·yr, and includes data with detector upgrades that have improved the energy threshold relative to previous searches. A lower limit of T1/2Xe136>4.3×1024 yr at 90% C.L. on the half-life of the spectral index n=1 Majoron decay was obtained, a factor of 3.6 more stringent than the previous limit from EXO-200 and a factor of 1.6 more stringent than the previous best limit from KamLAND-Zen. This limit corresponds to a constraint on the Majoron-neutrino coupling constant of |geeM|

Published
2021

12. Measurement of the Spectral Shape of the beta-decay of 137Xe to the Ground State of 137Cs in EXO-200 and Comparison with Theory

Author

Kharusi, S. Al, Anton, G., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Breidenbach, M., Brunner, T., Cao, G. F., Cen, W. R., Chambers, C., Cleveland, B., Coon, M., Craycraft, A., Daniels, T., Darroch, L., Daugherty, S. J., Davis, J., Delaquis, S., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Dolgolenko, A., Dolinski, M. J., Echevers, J., Fairbank Jr., W., Fairbank, D., Farine, J., Feyzbakhsh, S., Fierlinger, P., Fudenberg, D., Gautam, P., Gornea, R., Gratta, G., Hall, C., Hansen, E. V., Hoessl, J., Hufschmidt, P., Hughes, M., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Johnson, A., Karelin, A., Kaufman, L. J., Koffas, T., Kostensalo, J., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Lenardo, B. G., Leonard, D. S., Li, G. S., Li, S., Li, Z., Licciardi, C., Lin, Y. H., MacLellan, R., McElroy, T., Michel, T., Mong, B., Moore, D. C., Murray, K., Nakarmi, P., Njoya, O., Nusair, O., Odian, A., Ostrovskiy, I., Piepke, A., Pocar, A., Retière, F., Robinson, A. L., Rowson, P. C., Ruddell, D., Runge, J., Schmidt, S., Sinclair, D., Skarpaas, K., Soma, A. K., Stekhanov, V., Suhonen, J., Tarka, M., Thibado, S., Todd, J., Tolba, T., Totev, T. I., Tsang, R., Veenstra, B., Veeraraghavan, V., Vogel, P., Vuilleumier, J. -L., Wagenpfeil, M., Watkins, J., Weber, M., Wen, L. J., Wichoski, U., Wrede, G., Wu, S. X., Xia, Q., Yahne, D. R., Yang, L., Yen, Y. -R., Zeldovich, O. Ya., and Ziegler, T.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We report on a comparison between the theoretically predicted and experimentally measured spectra of the first-forbidden non-unique $\beta$-decay transition $^{137}\textrm{Xe}(7/2^-)\to\,^{137}\textrm{Cs}(7/2^+)$. The experimental data were acquired by the EXO-200 experiment during a deployment of an AmBe neutron source. The ultra-low background environment of EXO-200, together with dedicated source deployment and analysis procedures, allowed for collection of a pure sample of the decays, with an estimated signal-to-background ratio of more than 99-to-1 in the energy range from 1075 to 4175 keV. In addition to providing a rare and accurate measurement of the first-forbidden non-unique $\beta$-decay shape, this work constitutes a novel test of the calculated electron spectral shapes in the context of the reactor antineutrino anomaly and spectral bump., Comment: Version as accepted by PRL

Published
2020
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13. Reflectance of Silicon Photomultipliers at Vacuum Ultraviolet Wavelengths

Author

Lv, P., Cao, G. F., Wen, L. J., Kharusi, S. Al, Anton, G., Arnquist, I. J., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Breur, P. A., Brodsky, J. P., Brown, E., Brunner, T., Mamahit, S. Byrne, Caden, E., Cao, L., Chambers, C., Chana, B., Charlebois, S. A., Chiu, M., Cleveland, B., Coon, M., Craycraft, A., Dalmasson, J., Daniels, T., Darroch, L., Croix, A. De St., Der Mesrobian-Kabakian, A., Deslandes, K., DeVoe, R., Di Vacri, M. L., Dilling, J., Ding, Y. Y., Dolinski, M. J., Doria, L., Dragone, A., Echevers, J., Edaltafar, F., Elbeltagi, M., Fabris, L., Fairbank, D., Fairbank, W., Farine, J., Ferrara, S., Feyzbakhsh, S., Fucarino, A., Gallina, G., Gautam, P., Giacomini, G., Goeldi, D., Gornea, R., Gratta, G., Hansen, E. V., Heffner, M., Hoppe, E. W., Hößl, J., House, A., Hughes, M., Iverson, A., Jamil, A., Jewell, M. J., Jiang, X. S., Karelin, A., Kaufman, L. J., Koffas, T., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Leach, K. G., Lenardo, B. G., Leonard, D. S., Li, G., Li, S., Li, Z., Licciardi, C., MacLellan, R., Massacret, N., McElroy, T., Medina-Peregrina, M., Michel, T., Mong, B., Moore, D. C., Murray, K., Nakarmi, P., Natzke, C. R., Newby, R. J., Ning, Z., Njoya, O., Nolet, F., Nusair, O., Odgers, K., Odian, A., Oriunno, M., Orrell, J. L., Ortega, G. S., Ostrovskiy, I., Overman, C. T., Parent, S., Piepke, A., Pocar, A., Pratte, J. -F., Radeka, V., Raguzin, E., Rescia, S., Retière, F., Richman, M., Robinson, A., Rossignol, T., Rowson, P. C., Roy, N., Runge, J., Saldanha, R., Sangiorgio, S., VIII, K. Skarpaas, Soma, A. K., St-Hilaire, G., Stekhanov, V., Stiegler, T., Sun, X. L., Tarka, M., Todd, J., Totev, T. I., Tsang, R., Tsang, T., Vachon, F., Veeraraghavan, V., Viel, S., Visser, G., Vivo-Vilches, C., Vuilleumier, J. -L., Wagenpfeil, M., Wager, T., Walent, M., Wang, Q., Watkins, J., Wei, W., Wichoski, U., Wu, S. X., Wu, W. H., Wu, X., Xia, Q., Yang, H., Yang, L., Zeldovich, O., Zhao, J., Zhou, Y., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Characterization of the vacuum ultraviolet (VUV) reflectance of silicon photomultipliers (SiPMs) is important for large-scale SiPM-based photodetector systems. We report the angular dependence of the specular reflectance in a vacuum of SiPMs manufactured by Fondazionc Bruno Kessler (FBK) and Hamamatsu Photonics K.K. (HPK) over wavelengths ranging from 120 nm to 280 nm. Refractive index and extinction coefficient of the thin silicon-dioxide film deposited on the surface of the FBK SiPMs are derived from reflectance data of a FBK silicon wafer with the same deposited oxide film as SiPMs. The diffuse reflectance of SiPMs is also measured at 193 nm. We use the VUV spectral dependence of the optical constants to predict the reflectance of the FBK silicon wafer and FBK SiPMs in liquid xenon.

Published
2019
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14. Measurements of electron transport in liquid and gas Xenon using a laser-driven photocathode

Author

Njoya, O., Tsang, T., Tarka, M., Fairbank, W., Kumar, K. S., Rao, T., Wager, T., Kharusi, S. Al, Anton, G., Arnquist, I. J., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Brodsky, J. P., Brown, E., Brunner, T., Caden, E., Cao, G. F., Cao, L., Cen, W. R., Chambers, C., Chana, B., Charlebois, S. A., Chiu, M., Cleveland, B., Coon, M., Craycraft, A., Dalmasson, J., Daniels, T., Darroch, L., Daugherty, S. J., Croix, A. De St., Der Mesrobian-Kabakian, A., DeVoe, R., Di Vacri, M. L., Dilling, J., Ding, Y. Y., Dolinski, M. J., Dragone, A., Echevers, J., Elbeltagi, M., Fabris, L., Fairbank, D., Farine, J., Ferrara, S., Feyzbakhsh, S., Fontaine, R., Fucarino, A., Gallina, G., Gautam, P., Giacomini, G., Goeldi, D., Gornea, R., Gratta, G., Hansen, E. V., Heffner, M., Hoppe, E. W., Hossl, J., House, A., Hughes, M., Iverson, A., Jamil, A., Jewell, M. J., Jiang, X. S., Karelin, A., Kaufman, L. J., Kodroff, D., Koffas, T., Krucken, R., Kuchenkov, A., Lan, Y., Larson, A., Leach, K. G., Lenardo, B. G., Leonard, D. S., Li, G., Li, S., Li, Z., Licciardi, C., Lin, Y. H., Lv, P., MacLellan, R., McElroy, T., Medina-Peregrina, M., Michel, T., Mong, B., Moore, D. C., Murray, K., Nakarmi, P., Natzke, C. R., Newby, R. J., Ning, Z., Nolet, F., Nusair, O., Odgers, K., Odian, A., Oriunno, M., Orrell, J. L., Ortega, G. S., Ostrovskiy, I., Overman, C. T., Parent, S., Piepke, A., Pocar, A., Pratte, J. -F., Radeka, V., Raguzin, E., Rescia, S., Retiere, F., Richman, M., Robinson, A., Rossignol, T., Rowson, P. C., Roy, N., Runge, J., Saldanha, R., Sangiorgio, S., VIII, K. Skarpaas, Soma, A. K., St-Hilaire, G., Stekhanov, V., Stiegler, T., Sun, X. L., Todd, J., Tolba, T., Totev, T. I., Tsang, R., Vachon, F., Veeraraghavan, V., Viel, S., Visser, G., Vivo-Vilches, C., Vuilleumier, J. -L., Wagenpfeil, M., Walent, M., Wang, Q., Ward, M., Watkins, J., Weber, M., Wei, W., Wen, L. J., Wichoski, U., Wu, S. X., Wu, W. H., Wu, X., Xia, Q., Yang, H., Yang, L., Yen, Y. -R., Zeldovich, O., Zhao, J., Zhou, Y., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

Measurements of electron drift properties in liquid and gaseous xenon are reported. The electrons are generated by the photoelectric effect in a semi-transparent gold photocathode driven in transmission mode with a pulsed ultraviolet laser. The charges drift and diffuse in a small chamber at various electric fields and a fixed drift distance of 2.0 cm. At an electric field of 0.5 kV/cm, the measured drift velocities and corresponding temperature coefficients respectively are $1.97 \pm 0.04$ mm/$\mu$s and $(-0.69\pm0.05)$\%/K for liquid xenon, and $1.42 \pm 0.03$ mm/$\mu$s and $(+0.11\pm0.01)$\%/K for gaseous xenon at 1.5 bar. In addition, we measure longitudinal diffusion coefficients of $25.7 \pm 4.6$ cm$^2$/s and $149 \pm 23$ cm$^2$/s, for liquid and gas, respectively. The quantum efficiency of the gold photocathode is studied at the photon energy of 4.73 eV in liquid and gaseous xenon, and vacuum. These charge transport properties and the behavior of photocathodes in a xenon environment are important in designing and calibrating future large scale noble liquid detectors.

Published
2019
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15. Reflectivity and PDE of VUV4 Hamamatsu SiPMs in Liquid Xenon

Author

Nakarmi, P., Ostrovskiy, I., Soma, A. K., Retiere, F., Kharusi, S. Al, Alfaris, M., Anton, G., Arnquist, I. J., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Blatchford, J., Breur, P. A., Brodsky, J. P., Brown, E., Brunner, T., Mamahit, S. Byrne, Caden, E., Cao, G. F., Cao, L., Chambers, C., Chana, B., Charlebois, S. A., Chiu, M., Cleveland, B., Coon, M., Craycraft, A., Dalmasson, J., Daniels, T., Darroch, L., Croix, A. De St., Der Mesrobian-Kabakian, A., DeVoe, R., Di Vacri, M. L., Dilling, J., Ding, Y. Y., Dolinski, M. J., Doria, L., Dragone, A., Echevers, J., Edaltafar, F., Elbeltagi, M., Fabris, L., Fairbank, D., Fairbank, W., Farine, J., Ferrara, S., Feyzbakhsh, S., Fontaine, R., Fucarino, A., Gallina, G., Gautam, P., Giacomini, G., Goeldi, D., Gornea, R., Gratta, G., Hansen, E. V., Heffner, M., Hoppe, E. W., Hößle, J., House, A., Hughes, M., Iverson, A., Jamil, A., Jewell, M. J., Jiang, X. S., Karelin, A., Kaufman, L. J., Koffas, T., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Leach, K. G., Lenardo, B. G., Leonard, D. S., Li, G., Li, S., Li, Z., Licciardi, C., Lv, P., MacLellan, R., Massacret, N., McElroy, T., Medina-Peregrina, M., Michel, T., Mong, B., Moore, D. C., Murray, K., Natzke, C. R., Newby, R. J., Ning, Z., Njoya, O., Nolet, F., Nusair, O., Odgers, K., Odian, A., Oriunno, M., Orrell, l J. L., Ortega, G. S., Overman, C. T., Parent, S., Piepke, A., Pocar, A., Pratte, J. -F., Radeka, V., Raguzin, E., Rescia, S., Richman, M., Robinson, A., Rossignol, T., Rowson, P. C., Roy, N., Runge, J., Saldanha, R., Sangiorgio, S., VIII, K. Skarpaas, St-Hilaire, G., Stekhanov, r V., Stiegler, T., Sun, X. L., Tarka, M., Todd, J., Totev, T. I., Tsang, R., Tsang, T., Vachon, F., Veeraraghavan, V., Viel, S., Visser, G., Vivo-Vilches, C., Vuilleumier, J. -L., Wagenpfeil, M., Wager, T., Walent, M., Wang, Q., Ward, M., Watkins, J., Weber, M., Wei, W., Wen, L. J., Wichoski, U., Wu, S. X., Wu, W. H., Wu, X., Xia, Q., Yang, H., Yang, L., Zeldovich, O., Zhao, J., Zhou, Y., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Understanding reflective properties of materials and photodetection efficiency (PDE) of photodetectors is important for optimizing energy resolution and sensitivity of the next generation neutrinoless double beta decay, direct detection dark matter, and neutrino oscillation experiments that will use noble liquid gases, such as nEXO, DARWIN, DarkSide-20k, and DUNE. Little information is currently available about reflectivity and PDE in liquid noble gases, because such measurements are difficult to conduct in a cryogenic environment and at short enough wavelengths. Here we report a measurement of specular reflectivity and relative PDE of Hamamatsu VUV4 silicon photomultipliers (SiPMs) with 50 micrometer micro-cells conducted with xenon scintillation light (~175 nm) in liquid xenon. The specular reflectivity at 15 deg. incidence of three samples of VUV4 SiPMs is found to be 30.4+/-1.4%, 28.6+/-1.3%, and 28.0+/-1.3%, respectively. The PDE at normal incidence differs by +/-8% (standard deviation) among the three devices. The angular dependence of the reflectivity and PDE was also measured for one of the SiPMs. Both the reflectivity and PDE decrease as the angle of incidence increases. This is the first measurement of an angular dependence of PDE and reflectivity of a SiPM in liquid xenon., Comment: 21 pages, 15 figures, 6 tables. As accepted by JINST

Published
2019
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16. Measurement of the scintillation and ionization response of liquid xenon at MeV energies in the EXO-200 experiment

Author

Collaboration, EXO-200, Anton, G., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Breidenbach, M., Brunner, T., Cao, G. F., Cen, W. R., Chambers, C., Cleveland, B., Coon, M., Craycraft, A., Daniels, T., Darroch, L., Daugherty, S. J., Davis, J., Delaquis, S., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Dolgolenko, A., Dolinski, M. J., Echevers, J., Fairbank Jr., W., Fairbank, D., Farine, J., Feyzbakhsh, S., Fierlinger, P., Fudenberg, D., Gautam, P., Gornea, R., Gratta, G., Hall, C., Hansen, E. V., Hoessl, J., Hufschmidt, P., Hughes, M., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Johnson, A., Karelin, A., Kaufman, L. J., Koffas, T., Krucken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Lenardo, B. G., Leonard, D. S., Li, G. S., Li, S., Li, Z., Licciardi, C., Lin, Y. H., MacLellan, R., McElroy, T., Michel, T., Mong, B., Moore, D. C., Murray, K., Neilson, R., Njoya, O., Nusair, O., Odian, A., Ostrovskiy, I., Piepke, A., Pocar, A., Retiere, F., Robinson, A. L., Rowson, P. C., Runge, J., Schmidt, S., Sinclair, D., Soma, A. K., Stekhanov, V., Tarka, M., Todd, J., Tolba, T., Tosi, D., Totev, T. I., Veenstra, B., Veeraraghavan, V., Vuilleumier, J. -L., Wagenpfeil, M., Watkins, J., Weber, M., Wen, L. J., Wichoski, U., Wrede, G., Wu, S. X., Xia, Q., Yahne, D. R., Yang, L., Yen, Y. -R., Zeldovich, O. Ya., and Ziegle, T.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

Liquid xenon (LXe) is employed in a number of current and future detectors for rare event searches. We use the EXO-200 experimental data to measure the absolute scintillation and ionization yields generated by $\gamma$ interactions from $^{228}$Th (2615~keV), $^{226}$Ra (1764~keV) and $^{60}$Co (1332~keV and 1173~keV) calibration sources, over a range of electric fields. The $W$-value that defines the recombination-independent energy scale is measured to be $11.5~\pm~0.5$~(syst.)~$\pm~0.1$~(stat.) eV. These data are also used to measure the recombination fluctuations in the number of electrons and photons produced by the calibration sources at the MeV-scale, which deviate from extrapolations of lower-energy data. Additionally, a semi-empirical model for the energy resolution of the detector is developed, which is used to constrain the recombination efficiency, i.e., the fraction of recombined electrons that result in the emission of a detectable photon. Detailed measurements of the absolute charge and light yields for MeV-scale electron recoils are important for predicting the performance of future neutrinoless double beta decay detectors.

Published
2019
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17. Simulation of charge readout with segmented tiles in nEXO

Author

Li, Z., Cen, W. R., Robinson, A., Moore, D. C., Wen, L. J., Odian, A., Kharusi, S. Al, Anton, G., Arnquist, I. J., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Brodsky, J. P., Brown, E., Brunner, T., Caden, E., Cao, G. F., Cao, L., Chambers, C., Chana, B., Charlebois, S. A., Chiu, M., Cleveland, B., Coon, M., Craycraft, A., Dalmasson, J., Daniels, T., Darroch, L., Daugherty, S. J., Croix, A. De St., Der Mesrobian-Kabakian, A., DeVoe, R., Di Vacri, M. L., Dilling, J., Ding, Y. Y., Dolinski, M. J., Dragone, A., Echevers, J., Elbeltagi, M., Fabris, L., Fairbank, D., Fairbank, W., Farine, J., Ferrara, S., Feyzbakhsh, S., Fontaine, R., Fucarino, A., Gallina, G., Gautam, P., Giacomini, G., Goeldi, D., Gornea, R., Gratta, G., Hansen, E. V., Heffner, M., Hoppe, E. W., Hößl, J., House, A., Hughes, M., Iverson, A., Jamil, A., Jewell, M. J., Jiang, X. S., Karelin, A., Kaufman, L. J., Kodroff, D., Koffas, T., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Leach, K. G., Lenardo, B. G., Leonard, D. S., Li, G., Li, S., Licciardi, C., Lin, Y. H., Lv, P., MacLellan, R., McElroy, T., Medina-Peregrina, M., Michel, T., Mong, B., Murray, K., Nakarmi, P., Natzke, C. R., Newby, R. J., Ning, Z., Njoya, O., Nolet, F., Nusair, O., Odgers, K., Oriunno, M., Orrell, J. L., Ortega, G. S., Ostrovskiy, I., Overman, C. T., Parent, S., Piepke, A., Pocar, A., Pratte, J. -F., Radeka, V., Raguzin, E., Rescia, S., Retière, F., Richman, M., Rossignol, T., Rowson, P. C., Roy, N., Runge, J., Saldanha, R., Sangiorgio, S., VIII, K. Skarpaas, Soma, A. K., St-Hilaire, G., Stekhanov, V., Stiegler, T., Sun, X. L., Tarka, M., Todd, J., Tolba, T., Totev, T. I., Tsang, R., Tsang, T., Vachon, F., Veeraraghavan, V., Viel, S., Visser, G., Vivo-Vilches, C., Vuilleumier, J. -L., Wagenpfeil, M., Walent, M., Wang, Q., Ward, M., Watkins, J., Weber, M., Wei, W., Wichoski, U., Wu, S. X., Wu, W. H., Wu, X., Xia, Q., Yang, H., Yang, L., Yen, Y. -R., Zeldovich, O., Zhao, J., Zhou, Y., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

nEXO is a proposed experiment to search for the neutrino-less double beta decay ($0\nu\beta\beta$) of $^{136}$Xe in a tonne-scale liquid xenon time projection chamber (TPC). The nEXO TPC will be equipped with charge collection tiles to form the anode. In this work, the charge reconstruction performance of this anode design is studied with a dedicated simulation package. A multi-variate method and a deep neural network are developed to distinguish simulated $0\nu\beta\beta$ signals from backgrounds arising from trace levels of natural radioactivity in the detector materials. These simulations indicate that the nEXO TPC with charge-collection tiles shows promising capability to discriminate the $0\nu\beta\beta$ signal from backgrounds. The estimated half-life sensitivity for $0\nu\beta\beta$ decay is improved by $\sim$20$~(32)\%$ with the multi-variate~(deep neural network) methods considered here, relative to the sensitivity estimated in the nEXO pre-conceptual design report.

Published
2019
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18. Search for Neutrinoless Double-Beta Decay with the Complete EXO-200 Dataset

Author

Anton, G., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Breidenbach, M., Brunner, T., Cao, G. F., Cen, W. R., Chambers, C., Cleveland, B., Coon, M., Craycraft, A., Daniels, T., Danilov, M., Darroch, L., Daugherty, S. J., Davis, J., Delaquis, S., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Dolgolenko, A., Dolinski, M. J., Echevers, J., Fairbank Jr., W., Fairbank, D., Farine, J., Feyzbakhsh, S., Fierlinger, P., Fudenberg, D., Gautam, P., Gornea, R., Gratta, G., Hall, C., Hansen, E. V., Hoessl, J., Hufschmidt, P., Hughes, M., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Johnson, A., Karelin, A., Kaufman, L. J., Koffas, T., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Lenardo, B. G., Leonard, D. S., Li, G. S., Li, S., Li, Z., Licciardi, C., Lin, Y. H., MacLellan, R., McElroy, T., Michel, T., Mong, B., Moore, D. C., Murray, K., Njoya, O., Nusair, O., Odian, A., Ostrovskiy, I., Piepke, A., Pocar, A., Retière, F., Robinson, A. L., Rowson, P. C., Ruddell, D., Runge, J., Schmidt, S., Sinclair, D., Soma, A. K., Stekhanov, V., Tarka, M., Todd, J., Tolba, T., Totev, T. I., Veenstra, B., Veeraraghavan, V., Vogel, P., Vuilleumier, J. -L., Wagenpfeil, M., Watkins, J., Weber, M., Wen, L. J., Wichoski, U., Wrede, G., Wu, S. X., Xia, Q., Yahne, D. R., Yang, L., Yen, Y. -R., Zeldovich, O. Ya., and Ziegler, T.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

A search for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{136}$Xe is performed with the full EXO-200 dataset using a deep neural network to discriminate between $0\nu\beta\beta$ and background events. Relative to previous analyses, the signal detection efficiency has been raised from 80.8% to 96.4$\pm$3.0% and the energy resolution of the detector at the Q-value of $^{136}$Xe $0\nu\beta\beta$ has been improved from $\sigma/E=1.23\%$ to $1.15\pm0.02\%$ with the upgraded detector. Accounting for the new data, the median 90% confidence level $0\nu\beta\beta$ half-life sensitivity for this analysis is $5.0 \cdot 10^{25}$ yr with a total $^{136}$Xe exposure of 234.1 kg$\cdot$yr. No statistically significant evidence for $0\nu\beta\beta$ is observed, leading to a lower limit on the $0\nu\beta\beta$ half-life of $3.5\cdot10^{25}$ yr at the 90% confidence level., Comment: v1, 7 pages, 5 figures; v2, fix references; v3, update to accepted version

Published
2019
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19. Ground State Electromagnetic Moments of $^{37}$Ca

Author

Klose, A., Minamisono, K., Miller, A. J., Brown, B. A., Garand, D., Holt, J. D., Lantis, J. D., Liu, Y., Maaß, B., Nörtershäuser, W., Pineda, S. V., Rossi, D. M., Schwenk, A., Sommer, F., Sumithrarachchi, C., Teigelhöfer, A., and Watkins, J.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The hyperfine coupling constants of neutron deficient $^{37}$Ca were deduced from the atomic hyperfine spectrum of the $4s~^2S_{1/2}$ $\leftrightarrow$ $4p~^2P_{3/2}$ transition in Ca II, measured using the collinear laser spectroscopy technique. The ground-state magnetic-dipole and spectroscopic electric-quadrupole moments were determined for the first time as $\mu = +0.7453(72) \mu_N$ and $Q = -15(11)$ $e^2$fm$^2$, respectively. The experimental values agree well with nuclear shell model calculations using the universal sd model-space Hamiltonians versions A and B (USDA/B) in the $sd$-model space with a 95\% probability of the canonical nucleon configuration. It is shown that the magnetic moment of $^{39}$Ca requires a larger non-$sd$-shell component than that of $^{37}$Ca for good agreement with the shell-model calculation, indicating a more robust closed sub-shell structure of $^{36}$Ca at the neutron number $N$ = 16 than $^{40}$Ca. The results are also compared to valence-space in-medium similarity renormalization group calculations based on chiral two- and three-nucleon interactions.

Published
2019
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21. Risk of Bowel Obstruction in Patients Undergoing Neoadjuvant Chemotherapy for High-risk Colon Cancer: A Nested Case-control Matched Analysis of an International, Multi-centre, Randomised Controlled Trial (FOxTROT)

Author

Glasbey, James, Glasbey, James, Beggs, Andrew, Glimelius, Bengt, Gray, Richard, Handley, Kelly, Laurberg, Søren, Magill, Laura, Murakami, Keigo, Palmer, Andy, Quirke, Philip, Seligman, Jenny, Seymour, Matt, Sinha, Yash, West, Nick, Morton, Dion, Glasbey, James, Handley, Kelly, Palmer, Andy, Morton, Dion, Crosby, T., Olliff, J., Peto (Chair), R., Brown, Gina, Ferry, David, Glimelius, Bengt, Gray, Richard, Handley, Kelly, Ismail, Tariq, Laurberg, Søren, Magill, Laura, Morton, Dion, Oliver, Alf, Quirke, Phil, Seymour, Matt, Scott, Nigel, Seligman, Jenny, Swift, Ian, Warren, Bryan, West, Nick, Northover, J., Parmar (Chair), M., Slevin, M., Magill, Laura, Gray, Richard, Handley, Kelly, Wilcockson, Adrian, Gray, Zoe, Lancaster, Dominic, Brown, James, Palmer, Andrew, Adie, Ladan, Kennedy, Georgia, Eld, M., Holt, G., Yilmaz, M., Spendler, K. Garm, Hansen, F., Laurberg, S., Rosenkilde, M., Ahlstrom, H., Glimelius, B., Abgamu, D., Day, N., Walsh, C., Bannister, J., Furniss, D., Morgan, S., Walkington, L., Yates, S., Branagan, G., Mustajab, A., O’Neil, H., Rees, C., Geh, I., Hendrickse, C., Langman, G., Pallan, A., Conn, A., Lowe, A., Ostrowski, J., Steward, M., Callaway, M., Falk, S., Thomas, M., Wong, N., Cast, J., Hartley, J., Roy, R., Tiam, R., Blunt, D., Cleator, S., Dawson, P., Goldin, R., Gujral, D., Lowdell, C., Ziprin, P., Clenton, S., Dewdney, A., Euinton, H., Furniss, D., Gupta, R., Tarapowewalla, D., Wilshaw, V., Braun, M., Chakrabarty, B., Hill, J., Laasch, H., Saunders, M., Cruickshank, N., Davies, M., Muzaffar, S., Orme, A., Punia, P., Rea, D., Campbell, F., Hughes, M., Palmer, D., Rooney, P., Abbott, G., Hamid, B., Vimalachandran, D., Berry, J., Hinson, F., Maarouf, Z., Nicoll, J., Adams, C., Denson, J., Jackson, S., Sherriff, D., Kweka, E., McAdam, G., Peters, M., Roy, R., Khaira, M., Kurien, G., Robinson, J., Wadsley, J., White, D., Young, R., Dega, R., Lamparelli, M., Orbell, J., Osborne, R., Taylor, P., Thomas, T., Gopalakrishnan, K., Jadhav, V., Scott-Brown, M., Baijal, S., Chapman, M., Glaholm, J., Nelson, C., Singh, R., Harrison, J., Last, K., Scott, D., Scullion, D., Lind, P., Milosavljevic, Z., Dent, J., Ilsley, D., Littleford, S., Roberts, C., Crabtree, M., Orrell, J., Sherwin, E., Smith, S., Soomal, R., Braun, M., De, A., Khan, A., Khan, U., Lavin, V., McBain, C., Radharkrishna, G., Sil, R., Weerasinghe, S., Hill, J., Lee, S., Wright, P., Church, R., Holland, C., Kunene, V., Thompson, A., Glynne-Jones, R., Goh, V., Livingstone, J., Richman, P., Barlow, C., Burn, P., Geraghty, J., Walther, J., Grumett, S., Mangalika, S., Qaiyum, M., Williams, G., Borgstein, R., Bridgewater, J., Melville, D., Rees, J., Coxon, F., Hainsworth, P., Needham, S., Scott, J., Asmussen, J., Hansen, T., Jensen, K., Pfeiffer, P., Alkhaldi, A., Brittenden, J., Jackson, A., Kamposioras, K., Kumaran, G., Macklin, C., Alexander, J., Harle, A., Hickish, T., Talbot, R., Tarver, D., Bridgewater, J., Partridge, W., Sundaresan, V., Vivekanandan, S., Agrawal, N., Higginson, A., Muthuramalingam, S., O’Leary, D., Devarajan, G., Gulati, M., Kerwat, R., Maisey, N., Mikhaeel, G., Ismail, T., Middleton, G., Page, A., Steven, N., Taniere, P., Gutmann, J., Huang, J., Raouf, S., Dunn, W., Escola, C. Lopez, Potter, V., Scholefield, J., Walker, G., Zaitoun, A., Eason, D., McPhail, N., Mmeka, W., Stenhouse, G., Watson, A., Fozard, B., Hickish, T., Snape, S., Ellis, R., Faux, W., Jenkins, R., Maskell, G., Kulkarni, R., Lund, J., Menon, S., Singh, R., Chandler, I., Daniels, I., Harries, S., Osborne, M., Bell, J., Krell, D., Mayer, A., Ogunbiyi, O., Watkins, J., Bronder, C., Eaton, D., Taylor, A., Brown, G., Cunningham, D., Tekkis, P., Wotherspoon, A., Dobson, M., Mitchell, P., Pitt, M., Scott, N., Susnerwala, S., Adab, F., Britton, I., Ghiridaran, S., Howitt, C., Kirby, R., Biddlestone, L., Dalton, S., De Winton, E., Phillips, A., Ferry, D., Grumett, S., Kawesha, A., Maleki, K., Momtahan, N., Burnett, H., Hayes, S., Soop, M., Branagan, G., Cook, I., Cook, S., Iveson, T., Shablak, A., Coup, A., Hamid, A., Moore, P., O’Toole, L., Pai, D., Bateman, A., Bateman, A., Blaquiere, R., Nichols, P., Chappell, M., Dworkin, M., Jain, S., Tsang, D., Hopkins, K., Loveday, E., Lyons, A., Rooney, N., Ali, N., Chatterjee, M., Chiphang, A., Dundas, S., Myint, A. Sun, Zeiderman, M., Beharry, N., Chong, H., Lofts, F., Melville, D., Finan, P., Seymour, M., Tolan, D., West, N., Anyamene, N., Burling, D., Kennedy, R., Moorghen, M., Agrawal, S., Hasan, J., Mehta, S., Saeed, M., Burgess, P., John, L., Lowndes, S., Planner, A., Campbell, F., Hughes, M., Rooney, P., Smith, D., Hochhauser, D., Obichere, A., Rodriguez-Justo, M., Shiu, K., Taylor, S., Correa, P., James, S., Shatwell, W., Williams, N., Brady, J., Lanaspre, E., Mikhaeel, G., Ahmad, M., Gill, T., Wilson, D., Adams, R., Beehen, R., Morgan, M., Lindh, B., Adams, R., Morgan, M., Ford, A., Gopal, K., Pranesh, N., Shareef, D., Tighe, M., Busby, K., Correa, P., Sanders, S., Sinha, R., Ahmad, R., Desai, S., Ramesh, S., Hilman, S., Lott, M., O’Brien, J., Radstone, D., West, D., Amin, S., Hampton, J., Hornbuckle, J., Kitsanta, P., Ali, M., Desai, A., Hadaki, M., Hall, M., Arul, D., Hochhauser, D., Leonard, P., Mukhtar, H., Murray, D., Baxter, A., Churn, M., Farrugia, D., Lake, S., Smith, G., Bansal, A., Chandran, P., Corr, C., Gollins, S., Davenport, A., Saunders, M., Sukumar, S., Bathurst, N., Beaumont, E., Cooper, E., Francis, N., Sephton, M., Sparrow, G., Clarke, A., Haselden, J., Last, K., Woodcock, N., Atkinson, M., Gollins, S., Gupta, M., Maw, A., Abdullah, N., Bale, C., and Lord, M.

Published
2023
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22. Characterization of the Hamamatsu VUV4 MPPCs for nEXO

Author

Gallina, G., Giampa, P., Retiere, F., Kroeger, J., Zhang, G., Ward, M., Margetak, P., Lic, G., Tsang, T., Doria, L., Kharusi, S. Al, Alfaris, M., Anton, G., Arnquist, I. J., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Blatchford, J., Brodsky, J. P., Brown, E., Brunner, T., Cao, G. F., Cao, L., Cen, W. R., Chambers, C., Charlebois, S. A., Chiu, M., Cleveland, B., Coon, M., Craycraft, A., Dalmasson, J., Daniels, T., Darroch, L., Daugherty, S. J., Croix, A. De St., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Ding, Y. Y., Dolinski, M. J., Dragone, A., Echevers, J., Elbeltagi, M., Fabris, L., Fairbank, D., Fairbank, W., Farine, J., Feyzbakhsh, S., Fontaine, R., Gautam, P., Giacomini, G., Gornea, R., Gratta, G., Hansen, E. V., Heffner, M., Hoppe, E. W., Hoßl, J., House, A., Hughes, M., Ito, Y., Iverson, A., Jamil, A., Jewell, M. J., Jiang, X. S., Karelin, A., Kaufman, L. J., Kodroff, D., Koffas, T., Krucken, R., Kuchenkov, A., Kumar, K. S., Lana, Y., Larson, A., Lenardo, B. G., Leonarda, D. S., Lik, S., Li, Z., Licciardi, C., Linw, Y. H., Lv, P., MacLellan, R., McElroy, T., Medina-Peregrina, M., Michel, T., Mong, B., Moore, D. C., Murray, K., Nakarmi, P., Newby, R. J., Ning, Z., Njoya, O., Nolet, F., Nusair, O., Odgers, K., Odian, A., Oriunno, M., Orrell, J. L., Ortega, G. S., Ostrovskiy, I., Overman, C. T., Parent, S., Piepkez, A., Pocar, A., Pratte, J. -F., Qiu, D., Radeka, V., Raguzin, E., Rescia, S., Richman, M., Robinson, A., Rossignol, T., Rowson, P. C., Roy, N., Saldanha, R., Sangiorgio, S., VIII, K. Skarpaas, Soma, A. K., St-Hilaire, G., Stekhanov, V., Stiegler, T., Sun, X. L., Tarka, M., Todd, J., Tolba, T., Totev, T. I., Tsang, R., Vachon, F., Veeraraghavan, V., Visser, G., Vuilleumier, J. -L., Wagenpfeil, M., Walent, M., Wang, Q., Watkins, J., Weber, M., Wei, W., Wen, L. J., Wichoski, U., Wu, S. X., Wu, W. H., Wu, X., Xia, Q., Yang, H., Yang, L., Yen, Y. -R., Zeldovich, O., Zhao, J., Zhou, Y., and Ziegler, T.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract

In this paper we report on the characterization of the Hamamatsu VUV4 (S/N: S13370-6152) Vacuum Ultra-Violet (VUV) sensitive Silicon Photo-Multipliers (SiPMs) as part of the development of a solution for the detection of liquid xenon scintillation light for the nEXO experiment. Various SiPM features, such as: dark noise, gain, correlated avalanches, direct crosstalk and Photon Detection Efficiency (PDE) were measured in a dedicated setup at TRIUMF. SiPMs were characterized in the range $163 \text{ } \text{K} \leq \text{T}\leq 233 \text{ } \text{K}$. At an over voltage of $3.1\pm0.2$ V and at $\text{T}=163 \text{ }\text{K}$ we report a number of Correlated Avalanches (CAs) per pulse in the $1 \upmu\text{s}$ interval following the trigger pulse of $0.161\pm0.005$. At the same settings the Dark-Noise (DN) rate is $0.137\pm0.002 \text{ Hz/mm}^{2}$. Both the number of CAs and the DN rate are within nEXO specifications. The PDE of the Hamamatsu VUV4 was measured for two different devices at $\text{T}=233 \text{ }\text{K}$ for a mean wavelength of $189\pm7\text{ nm}$. At $3.6\pm0.2$ V and $3.5\pm0.2$ V of over voltage we report a PDE of $13.4\pm2.6\text{ }\%$ and $11\pm2\%$, corresponding to a saturation PDE of $14.8\pm2.8\text{ }\%$ and $12.2\pm2.3\%$, respectively. Both values are well below the $24\text{ }\%$ saturation PDE advertised by Hamamatsu. More generally, the second device tested at $3.5\pm0.2$ V of over voltage is below the nEXO PDE requirement. The first one instead yields a PDE that is marginally close to meeting the nEXO specifications. This suggests that with modest improvements the Hamamatsu VUV4 MPPCs could be considered as an alternative to the FBK-LF SiPMs for the final design of the nEXO detector.

Published
2019
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23. Study of Silicon Photomultiplier Performance in External Electric Fields

Author

Sun, X. L., Tolba, T., Cao, G. F., Lv, P., Wen, L. J., Odian, A., Vachon, F., Alamre, A., Albert, J. B., Anton, G., Arnquist, I. J., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Bourque, F., Brodsky, J. P., Brown, E., Brunner, T., Burenkov, A., Cao, L., Cen, W. R., Chambers, C., Charlebois, S. A., Chiu, M., Cleveland, B., Coon, M., Côté, M., Craycraft, A., Cree, W., Dalmasson, J., Daniels, T., Darroch, L., Daugherty, S. J., Daughhetee, J., Delaquis, S., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Ding, Y. Y., Dolinski, M. J., Dragone, A., Echevers, J., Fabris, L., Fairbank, D., Fairbank, W., Farine, J., Feyzbakhsh, S., Fierlinger, P., Fontaine, R., Fudenberg, D., Gallina, G., Giacomini, G., Gornea, R., Gratta, G., Hansen, E. V., Harris, D., Heffner, M., Hoppe, E. W., Hößl, J., House, A., Hufschmidt, P., Hughes, M., Ito, Y., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Jiang, X. S., Karelin, A., Kaufman, L. J., Kodroff, D., Koffas, T., Kravitz, S., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Leonard, D. S., Li, G., Li, S., Li, Z., Licciardi, C., Lin, Y. H., MacLellan, R., Michel, T., Moe, M., Mong, B., Moore, D. C., Murray, K., Newby, R. J., Ning, Z., Njoya, O., Nolet, F., Nusair, O., Odgers, K., Oriunno, M., Orrell, J. L., Ortega, G. S., Ostrovskiy, I., Overman, C. T., Parent, S., Piepke, A., Pocar, A., Pratte, J. -F., Qiu, D., Radeka, V., Raguzin, E., Rao, T., Rescia, S., Retière, F., Robinson, A., Rossignol, T., Rowson, P. C., Roy, N., Saldanha, R., Sangiorgio, S., Schmidt, S., Schneider, J., Sinclair, D., VIII, K. Skarpaas, Soma, A. K., St-Hilaire, G., Stekhanov, V., Stiegler, T., Tarka, M., Todd, J., Totev, T. I., Tsang, R., Tsang, T., Veenstra, B., Veeraraghavan, V., Visser, G., Vuilleumier, J. -L., Wagenpfeil, M., Wang, Q., Watkins, J., Weber, M., Wei, W., Wichoski, U., Wrede, G., Wu, S. X., Wu, W. H., Xia, Q., Yang, L., Yen, Y. -R., Zeldovich, O., Zhao, J., Zhou, Y., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors
Abstract

We report on the performance of silicon photomultiplier (SiPM) light sensors operating in electric field strength up to 30 kV/cm and at a temperature of 149K, relative to their performance in the absence of an external electric field. The SiPM devices used in this study show stable gain, photon detection efficiency, and rates of correlated pulses, when exposed to external fields, within the estimated uncertainties. No observable physical damage to the bulk or surface of the devices was caused by the exposure., Comment: 16 pages, 12 figures, 2 tables and two conferences (INPC2016 and TIPP2017)

Published
2018
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24. Imaging individual barium atoms in solid xenon for barium tagging in nEXO

Author

Chambers, C., Walton, T., Fairbank, D., Craycraft, A., Yahne, D. R., Todd, J., Iverson, A., Fairbank, W., Alamare, A., Albert, J. B., Anton, G., Arnquist, I. J., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Bourque, F., Brodsky, J. P., Brown, E., Brunner, T., Burenkov, A., Cao, G. F., Cao, L., Cen, W. R., Charlebois, S. A., Chiu, M., Cleveland, B., Coon, M., Cree, W., Côté, M., Dalmasson, J., Daniels, T., Darroch, L., Daugherty, S. J., Daughhetee, J., Delaquis, S., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Ding, Y. Y., Dolinski, M. J., Dragone, A., Echevers, J., Fabris, L., Farine, J., Feyzbakhsh, S., Fontaine, R., Fudenberg, D., Giacomini, G., Gornea, R., Gratta, G., Hansen, E. V., Heffner, M., Hoppe, E. W., Hößl, J., House, A., Hufschmidt, P., Hughes, M., Ito, Y., Jamil, A., Jessiman, C., Jewell, M. J., Jiang, X. S., Karelin, A., Kaufman, L. J., Kodroff, D., Koffas, T., Kravitz, S., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Leonard, D. S., Li, G., Li, S., Li, Z., Licciardi, C., Lin, Y. H., Lv, P., MacLellan, R., Michel, T., Mong, B., Moore, D. C., Murray, K., Newby, R. J., Ning, Z., Njoya, O., Nolet, F., Nusair, O., Odgers, K., Odian, A., Oriunno, M., Orrell, J. L., Ortega, G. S., Ostrovskiy, I., Overman, C. T., Parent, S., Piepke, A., Pocar, A., Pratte, J. -F., Qiu, D., Radeka, V., Raguzin, E., Rao, T., Rescia, S., Retière, F., Robinson, A., Rossignol, T., Rowson, P. C., Roy, N., Saldanha, R., Sangiorgio, S., Schmidt, S., Schneider, J., Schubert, A., Sinclair, D., VIII, K. Skarpaas, Soma, A. K., St-Hilaire, G., Stekhanov, V., Stiegler, T., Sun, X. L., Tarka, M., Tolba, T., Tsang, T. I. Totev. R., Tsang, T., Vachon, F., Veenstra, B., Veeraraghavan, V., Visser, G., Vuilleumier, J. -L., Wagenpfeil, M., Wang, Q., Watkins, J., Weber, M., Wei, W., Wen, L. J., Wichoski, U., Wrede, G., Wu, S. X., Wu, W. H., Xia, Q., Yang, L., Yen, Y. -R., Zeldovich, O., Zhang, X., Zhao, J., Zhou, Y., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

The search for neutrinoless double beta decay probes the fundamental properties of neutrinos, including whether or not the neutrino and antineutrino are distinct. Double beta detectors are large and expensive, so background reduction is essential for extracting the highest sensitivity. The identification, or 'tagging', of the $^{136}$Ba daughter atom from double beta decay of $^{136}$Xe provides a technique for eliminating backgrounds in the nEXO neutrinoless double beta decay experiment. The tagging scheme studied in this work utilizes a cryogenic probe to trap the barium atom in solid xenon, where the barium atom is tagged via fluorescence imaging in the solid xenon matrix. Here we demonstrate imaging and counting of individual atoms of barium in solid xenon by scanning a focused laser across a solid xenon matrix deposited on a sapphire window. When the laser sits on an individual atom, the fluorescence persists for $\sim$30~s before dropping abruptly to the background level, a clear confirmation of one-atom imaging. No barium fluorescence persists following evaporation of a barium deposit to a limit of $\leq$0.16\%. This is the first time that single atoms have been imaged in solid noble element. It establishes the basic principle of a barium tagging technique for nEXO.

Published
2018

25. nEXO Pre-Conceptual Design Report

Author

nEXO Collaboration, Kharusi, S. Al, Alamre, A., Albert, J. B., Alfaris, M., Anton, G., Arnquist, I. J., Badhrees, I., Barbeau, P. S., Beck, D., Belov, V., Bhatta, T., Bourque, F., Brodsky, J. P., Brown, E., Brunner, T., Burenkov, A., Cao, G. F., Cao, L., Cen, W. R., Chambers, C., Charlebois, S. A., Chiu, M., Cleveland, B., Conley, R., Coon, M., Côté, M., Craycraft, A., Cree, W., Dalmasson, J., Daniels, T., Danovitch, D., Darroch, L., Daugherty, S. J., Daughhetee, J., DeVoe, R., Delaquis, S., Der Mesrobian-Kabakian, A., Di Vacri, M. L., Dilling, J., Ding, Y. Y., Dolinski, M. J., Dragone, A., Echevers, J., Fabris, L., Fairbank, D., Fairbank, W., Farine, J., Ferrara, S., Feyzbakhsh, S., Fierlinger, P., Fontaine, R., Fudenberg, D., Gallina, G., Giacomini, G., Gornea, R., Gratta, G., Haller, G., Hansen, E. V., Harris, D., Hasi, J., Heffner, M., Hoppe, E. W., Hößl, J., House, A., Hufschmidt, P., Hughes, M., Ito, Y., Iverson, A., Jamil, A., Jessiman, C., Jewell, M. J., Jiang, X. S., Karelin, A., Kaufman, L. J., Kenney, C., Killick, R., Kodroff, D., Koffas, T., Kravitz, S., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Larson, A., Lenardo, B. G., Leonard, D. S., Lewis, C. M., Li, G., Li, S., Li, Z., Licciardi, C., Lin, Y. H., Lv, P., MacLellan, R., McFarlane, K., Michel, T., Mong, B., Moore, D. C., Murray, K., Newby, R. J., Nguyen, T., Ning, Z., Njoya, O., Nolet, F., Nusair, O., Odgers, K., Odian, A., Oriunno, M., Orrell, J. L., Ortega, G. S., Ostrovskiy, I., Overman, C. T., Parent, S., Patel, M., Peña-Perez, A., Piepke, A., Pocar, A., Pratte, J. -F., Qiu, D., Radeka, V., Raguzin, E., Rao, T., Rescia, S., Retière, F., Robinson, A., Rossignol, T., Rowson, P. C., Roy, N., Runge, J., Saldanha, R., Sangiorgio, S., Schmidt, S., Schneider, J., Schubert, A., Segal, J., Skarpaas~VIII, K., Soma, A. K., Spitaels, K., St-Hilaire, G., Stekhanov, V., Stiegler, T., Sun, X. L., Tarka, M., Todd, J., Tolba, T., Totev, T. I., Tsang, R., Tsang, T., Vachon, F., Veenstra, B., Veeraraghavan, V., Visser, G., Vogel, P., Vuilleumier, J. -L., Wagenpfeil, M., Wang, Q., Ward, M., Watkins, J., Weber, M., Wei, W., Wen, L. J., Wichoski, U., Wrede, G., Wu, S. X., Wu, W. H., Xia, Q., Yang, L., Yen, Y. -R., Zeldovich, O., Zhang, X., Zhao, J., Zhou, Y., and Ziegler, T.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

The projected performance and detector configuration of nEXO are described in this pre-Conceptual Design Report (pCDR). nEXO is a tonne-scale neutrinoless double beta ($0\nu\beta\beta$) decay search in $^{136}$Xe, based on the ultra-low background liquid xenon technology validated by EXO-200. With $\simeq$ 5000 kg of xenon enriched to 90% in the isotope 136, nEXO has a projected half-life sensitivity of approximately $10^{28}$ years. This represents an improvement in sensitivity of about two orders of magnitude with respect to current results. Based on the experience gained from EXO-200 and the effectiveness of xenon purification techniques, we expect the background to be dominated by external sources of radiation. The sensitivity increase is, therefore, entirely derived from the increase of active mass in a monolithic and homogeneous detector, along with some technical advances perfected in the course of a dedicated R&D program. Hence the risk which is inherent to the construction of a large, ultra-low background detector is reduced, as the intrinsic radioactive contamination requirements are generally not beyond those demonstrated with the present generation $0\nu\beta\beta$ decay experiments. Indeed, most of the required materials have been already assayed or reasonable estimates of their properties are at hand. The details described herein represent the base design of the detector configuration as of early 2018. Where potential design improvements are possible, alternatives are discussed. This design for nEXO presents a compelling path towards a next generation search for $0\nu\beta\beta$, with a substantial possibility to discover physics beyond the Standard Model., Comment: 182 pages, minor revisions

Published
2018

26. Deep Neural Networks for Energy and Position Reconstruction in EXO-200

Author

Delaquis, S., Jewell, M. J., Ostrovskiy, I., Weber, M., Ziegler, T., Dalmasson, J., Kaufman, L. J., Richards, T., Albert, J. B., Anton, G., Badhrees, I., Barbeau, P. S., Bayerlein, R., Beck, D., Belov, V., Breidenbach, M., Brunner, T., Cao, G. F., Cen, W. R., Chambers, C., Cleveland, B., Coon, M., Craycraft, A., Cree, W., Daniels, T., Danilov, M., Daugherty, S. J., Daughhetee, J., Davis, J., Der Mesrobian-Kabakian, A., DeVoe, R., Dilling, J., Dolgolenko, A., Dolinski, M. J., Fairbank Jr., W., Farine, J., Feyzbakhsh, S., Fierlinger, P., Fudenberg, D., Gornea, R., Gratta, G., Hall, C., Hansen, E. V., Harris, D., Hoessl, J., Hufschmidt, P., Hughes, M., Iverson, A., Jamil, A., Johnson, A., Karelin, A., Koffas, T., Kravitz, S., Krücken, R., Kuchenkov, A., Kumar, K. S., Lan, Y., Leonard, D. S., Li, G. S., Li, S., Licciardi, C., Lin, Y. H., MacLellan, R., Michel, T., Mong, B., Moore, D., Murray, K., Njoya, O., Odian, A., Piepke, A., Pocar, A., Retière, F., Robinson, A. L., Rowson, P. C., Schmidt, S., Schubert, A., Sinclair, D., Soma, A. K., Stekhanov, V., Tarka, M., Todd, J., Tolba, T., Veeraraghavan, V., Vuilleumier, J. -L., Wagenpfeil, M., Waite, A., Watkins, J., Wen, L. J., Wichoski, U., Wrede, G., Xia, Q., Yang, L., Yen, Y. -R., and Zeldovich, O. Ya.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract

We apply deep neural networks (DNN) to data from the EXO-200 experiment. In the studied cases, the DNN is able to reconstruct the relevant parameters - total energy and position - directly from raw digitized waveforms, with minimal exceptions. For the first time, the developed algorithms are evaluated on real detector calibration data. The accuracy of reconstruction either reaches or exceeds what was achieved by the conventional approaches developed by EXO-200 over the course of the experiment. Most existing DNN approaches to event reconstruction and classification in particle physics are trained on Monte Carlo simulated events. Such algorithms are inherently limited by the accuracy of the simulation. We describe a unique approach that, in an experiment such as EXO-200, allows to successfully perform certain reconstruction and analysis tasks by training the network on waveforms from experimental data, either reducing or eliminating the reliance on the Monte Carlo., Comment: Accepted version. 33 pages, 28 figures

Published
2018
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28. Research on Leadership: Running in Place or Fermenting Old Wine in a New Bottle?

Author

Watkins, J. Foster and Watkins, Sally R.

Abstract

A retired professor of educational leadership/higher education looks back to the literature review in his dissertations (1966) and moves forward over some 50 years of his personal research and his collaboration with his colleagues and doctoral students. The resulting document from the reflective process is shared in this submission. As reflected in the title, the position is taken that the leadership research has been "running in place" and the summary position is advanced that "we have been fermenting old wine in a new bottle". A bibliography is included.

Published
2015

32. The Public Schools Cannot Do It Alone

Author

Watkins, J. Foster

Abstract

The longstanding concerns of the author relative to society's tendency to make the public schools "responsible for all of society's problems" is addressed. The concerns as updated in this article have been expressed over the years as the author moved around the southeast in several letters to editors along the way.

Published
2014

33. Reflections on Dean Truman Pierce as Educator, Boss, Mentor and Friend

Author

Watkins, J. Foster

Abstract

The author was invited to submit a reflective piece relative to his relationships with Dean Truman Pierce over the years to be presented on "The 30th Anniversary Celebration of the Truman Pierce Institute" at Auburn University. It was included in the program for the event.

Published
2012

37. NEOWISE Studies of Asteroids with Sloan Photometry: Preliminary Results

Author

Mainzer, A., Masiero, J., Grav, T., Bauer, J., Tholen, D. J., McMillan, R. S., Wright, E., Spahr, T., Cutri, R. M., Walker, R., Mo, W., Watkins, J., Hand, E., and Maleszewski, C.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We have combined the NEOWISE and Sloan Digital Sky Survey data to study the albedos of 24,353 asteroids with candidate taxonomic classifications derived using Sloan photometry. We find a wide range of moderate to high albedos for candidate S-type asteroids that are analogous to the S-complex defined by previous spectrophotometrically-based taxonomic systems. The candidate C-type asteroids, while generally very dark, have a tail of higher albedos that overlaps the S types. The albedo distribution for asteroids with a photometrically derived Q classification is extremely similar to those of the S types. Asteroids with similar colors to (4) Vesta have higher albedos than the S types, and most have orbital elements similar to known Vesta family members. Finally, we show that the relative reflectance at 3.4 and 4.6 $\mu$m is higher for D-type asteroids and suggest that their red visible and near-infrared spectral slope extends out to these wavelengths. Understanding the relationship between size, albedo, and taxonomic classification is complicated by the fact that the objects with classifications were selected from the visible/near-infrared Sloan Moving Object Catalog, which is biased against fainter asteroids, including those with lower albedos., Comment: ApJ accepted

Published
2011
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38. NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results

Author

Mainzer, A., Grav, T., Masiero, J., Bauer, J., Hand, E., Tholen, D., McMillan, R. S., Spahr, T., Cutri, R. M., Wright, E., Watkins, J., Mo, W., and Maleszewski, C.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The NEOWISE dataset offers the opportunity to study the variations in albedo for asteroid classification schemes based on visible and near-infrared observations for a large sample of minor planets. We have determined the albedos for nearly 1900 asteroids classified by the Tholen, Bus and Bus-DeMeo taxonomic classification schemes. We find that the S-complex spans a broad range of bright albedos, partially overlapping the low albedo C-complex at small sizes. As expected, the X-complex covers a wide range of albedos. The multi-wavelength infrared coverage provided by NEOWISE allows determination of the reflectivity at 3.4 and 4.6 $\mu$m relative to the visible albedo. The direct computation of the reflectivity at 3.4 and 4.6 $\mu$m enables a new means of comparing the various taxonomic classes. Although C, B, D and T asteroids all have similarly low visible albedos, the D and T types can be distinguished from the C and B types by examining their relative reflectance at 3.4 and 4.6 $\mu$m. All of the albedo distributions are strongly affected by selection biases against small, low albedo objects, as all objects selected for taxonomic classification were chosen according to their visible light brightness. Due to these strong selection biases, we are unable to determine whether or not there are correlations between size, albedo and space weathering. We argue that the current set of classified asteroids makes any such correlations difficult to verify. A sample of taxonomically classified asteroids drawn without significant albedo bias is needed in order to perform such an analysis., Comment: Accepted to ApJ

Published
2011
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39. NEOWISE Observations of Near-Earth Objects: Preliminary Results

Author

Mainzer, A., Grav, T., Bauer, J., Masiero, J., McMillan, R. S., Cutri, R. M., Walker, R., Wright, E., Eisenhardt, P., Tholen, D. J., Spahr, T., Jedicke, R., Denneau, L., DeBaun, E., Elsbury, D., Gautier, T., Gomillion, S., Hand, E., Mo, W., Watkins, J., Wilkins, A., Bryngelson, G. L., Molina, A. Del Pino, Desai, S., Camus, M. Go'mez, Hidalgo, S. L., Konstantopoulos, I., Larsen, J. A., Maleszewski, C., Malkan, M. A., Mauduit, J. -C., Mullan, B. L., Olszewski, E. W., Pforr, J., Saro, A., Scotti, J. V., and Wasserman, L. H.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

With the NEOWISE portion of the \emph{Wide-field Infrared Survey Explorer} (WISE) project, we have carried out a highly uniform survey of the near-Earth object (NEO) population at thermal infrared wavelengths ranging from 3 to 22 $\mu$m, allowing us to refine estimates of their numbers, sizes, and albedos. The NEOWISE survey detected NEOs the same way whether they were previously known or not, subject to the availability of ground-based follow-up observations, resulting in the discovery of more than 130 new NEOs. The survey's uniformity in sensitivity, observing cadence, and image quality have permitted extrapolation of the 428 near-Earth asteroids (NEAs) detected by NEOWISE during the fully cryogenic portion of the WISE mission to the larger population. We find that there are 981$\pm$19 NEAs larger than 1 km and 20,500$\pm$3000 NEAs larger than 100 m. We show that the Spaceguard goal of detecting 90% of all 1 km NEAs has been met, and that the cumulative size distribution is best represented by a broken power law with a slope of 1.32$\pm$0.14 below 1.5 km. This power law slope produces $\sim13,200\pm$1,900 NEAs with $D>$140 m. Although previous studies predict another break in the cumulative size distribution below $D\sim$50-100 m, resulting in an increase in the number of NEOs in this size range and smaller, we did not detect enough objects to comment on this increase. The overall number for the NEA population between 100-1000 m are lower than previous estimates. The numbers of near-Earth comets will be the subject of future work., Comment: Accepted to ApJ

Published
2011
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41. Collector probe analysis of tungsten transport to the far-SOL from the DIII-D SAS-VW divertor experiment

Author

Messer, S.H., primary, Mateja, J.D., additional, Nichols, J.H., additional, Cacheris, A., additional, Duran, J.D., additional, Zamperini, S.A., additional, Sinclair, G., additional, Donovan, D., additional, Abrams, T., additional, Odstrcil, T., additional, Ren, J., additional, Garcia, W., additional, Unterberg, E.A., additional, Stangeby, P.C., additional, Rudakov, D.L., additional, Elder, J.D., additional, and Watkins, J., additional

Published
2024
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47. NEOWISE OBSERVATIONS OF NEAR-EARTH OBJECTS: PRELIMINARY RESULTS

Author

Mainzer, A, Grav, T, Bauer, J, Masiero, J, McMillan, RS, Cutri, RM, Walker, R, Wright, E, Eisenhardt, P, Tholen, DJ, Spahr, T, Jedicke, R, Denneau, L, DeBaun, E, Elsbury, D, Gautier, T, Gomillion, S, Hand, E, Mo, W, Watkins, J, Wilkins, A, Bryngelson, GL, Del Pino Molina, A, Desai, S, Camus, M Gómez, Hidalgo, SL, Konstantopoulos, I, Larsen, JA, Maleszewski, C, Malkan, MA, Mauduit, J-C, Mullan, BL, Olszewski, EW, Pforr, J, Saro, A, Scotti, JV, and Wasserman, LH

Subjects
infrared: planetary systems, minor planets, asteroids: general, planets and satellites: general, surveys, astro-ph.EP, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

With the NEOWISE portion of the Wide-field Infrared Survey Explorer (WISE) project, we have carried out a highly uniform survey of the near-Earth object (NEO) population at thermal infrared wavelengths ranging from 3 to 22 μm, allowing us to refine estimates of their numbers, sizes, and albedos. The NEOWISE survey detected NEOs the same way whether they were previously known or not, subject to the availability of ground-based follow-up observations, resulting in the discovery of more than 130 new NEOs. The survey's uniform sensitivity, observing cadence, and image quality have permitted extrapolation of the 428 near-Earth asteroids (NEAs) detected by NEOWISE during the fully cryogenic portion of the WISEmission to the larger population. We find that there are 981 19 NEAs larger than 1km and 20,500 3000 NEAs larger than 100m. We show that the Spaceguard goal of detecting 90% of all 1km NEAs has been met, and that the cumulative size distribution is best represented by a broken power law with a slope of 1.32 0.14 below 1.5km. This power-law slope produces 13, 200 1900 NEAs with D > 140m. Although previous studies predict another break in the cumulative size distribution below D 50-100m, resulting in an increase in the number of NEOs in this size range and smaller, we did not detect enough objects to comment on this increase. The overall number for the NEA population between 100 and 1000m is lower than previous estimates. The numbers of near-Earth comets and potentially hazardous NEOs will be the subject of future work. © 2011. The American Astronomical Society. All rights reserved.

Published
2011

49. A Viable Partnership for School Renewal

Author

Watkins, J. Foster

Abstract

In a foreword introducing a book edited by Carson and Smith (1993), the position is taken that a viable partnership in school renewal should be considered by the principal and the library media specialist. Key elements are discussed in the foreword, and developed further in the book, that must be considered in developing such a team approach. The emerging definition of the role of the library media specialist is advanced as having potential for assisting the principal in his instructional leadership responsibilities. Such a team approach has significant implications for improving classroom instruction. [This article was printed as the Foreword in: "Renewal at the Schoolhouse: Management Ideas for Library Media Specialists and Administrators" edited by Ben B. Carson and Jane Brady Smith (Englewood, CO: Libraries Unlimited, Inc., 1993), ix-xi.]

Published
1993

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