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1,753 results on '"Barlow, D."'

2. Storage of ultracold neutrons in the UCN$\tau$ magneto-gravitational trap

Author

Salvat, D. J., Adamek, E. R., Barlow, D., Broussard, L. J., Bowman, J. D., Callahan, N. B., Clayton, S. M., Cude-Woods, C., Currie, S., Dees, E. B., Fox, W., Geltenbort, P., Hickerson, K. P., Holley, A. T., Liu, C. -Y., Makela, M., Medina, J., Morley, D. J., Morris, C. L., Penttila, S. I., Ramsey, J., Saunders, A., Seestrom, S. J., Sjue, S. K. L., Slaughter, B. A., Sharapov, E. I., Vanderwerp, J., VornDick, B., Walstrom, P. L., Wang, Z., Womack, T. L., and Young, A. R.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

The UCN$\tau$ experiment is designed to measure the lifetime $\tau_{n}$ of the free neutron by trapping ultracold neutrons (UCN) in a magneto-gravitational trap. An asymmetric bowl-shaped NdFeB magnet Halbach array confines low-field-seeking UCN within the apparatus, and a set of electromagnetic coils in a toroidal geometry provide a background "holding" field to eliminate depolarization-induced UCN loss caused by magnetic field nodes. We present a measurement of the storage time $\tau_{store}$ of the trap by storing UCN for various times, and counting the survivors. The data are consistent with a single exponential decay, and we find $\tau_{store}=860\pm19$ s: within $1 \sigma$ of current global averages for $\tau_{n}$. The storage time with the holding field deactiveated is found to be $\tau_{store}=470 \pm 160$ s; this decreased storage time is due to the loss of UCN which undergo Majorana spin-flips while being stored. We discuss plans to increase the statistical sensitivity of the measurement and investigate potential systematic effects., Comment: 6 pages, 5 figures

Published
2013
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7. Status of the UCNτ experiment

Author

Pattie R.W., Callahan N.B., Cude-Woods C., Adamek E.R., Adams M., Barlow D., Blatnik M., D. Bowman, Broussard L.J., Clayton S., Currie S., Dees E.B., Ding X., Fellers D., Fox W., Fries E., Gonzalez F., Geltenbort P., Hickerson K.P., Hoffbauer M.A., Hoffman K., Holley A.T., Howard D., Ito T.M., Komives A., Liu C.Y., M. Makela, Medina J., Morley D., Morris C.L., O'Connor T., Penttilä S.I., Ramsey J.C., Roberts A., Salvat D., Saunders A., Seestrom S.J., Sharapov E.I., Sjue S.K.L., Snow W.M., Sprow A., Vanderwerp J., Vogelaar B., P.L. Walstrom, Wang Z., Weaver H., Wexler J., Womack T.L., Young A.R., and Zeck B.A.

Subjects
Physics, QC1-999
Abstract

The neutron is the simplest nuclear system that can be used to probe the structure of the weak interaction and search for physics beyond the standard model. Measurements of neutron lifetime and β-decay correlation coefficients with precisions of 0.02% and 0.1%, respectively, would allow for stringent constraints on new physics. The UCNτ experiment uses an asymmetric magneto-gravitational UCN trap with in situ counting of surviving neutrons to measure the neutron lifetime, τn = 877.7s (0.7s)stat (+0.4/−0.2s)sys. We discuss the recent result from UCNτ, the status of ongoing data collection and analysis, and the path toward a 0.25 s measurement of the neutron lifetime with UCNτ.

Published
2019
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8. Role of hot electrons in shock ignition constrained by experiment at the National Ignition Facility

Author

Barlow, D., primary, Goffrey, T., additional, Bennett, K., additional, Scott, R. H. H., additional, Glize, K., additional, Theobald, W., additional, Anderson, K., additional, Solodov, A. A., additional, Rosenberg, M. J., additional, Hohenberger, M., additional, Woolsey, N. C., additional, Bradford, P., additional, Khan, M., additional, and Arber, T. D., additional

Published
2022
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10. Seasonal, Annual, and Decadal Distribution of Three Rorqual Whale Species Relative to Dynamic Ocean Conditions Off Oregon, USA

Author

Derville, S., Barlow, D. R., Hayslip, C., Torres, L. G., Derville, S., Barlow, D. R., Hayslip, C., and Torres, L. G.

Abstract

Whale populations recovering from historical whaling are particularly vulnerable to incidental mortality and disturbance caused by growing ocean industrialization. Several distinct populations of rorqual whales (including humpback, blue, and fin whales) migrate and feed off the coast of Oregon, USA where spatial overlap with human activities are on the rise. Effective mitigation of conflicts requires better foundational understanding of spatial and temporal habitat use patterns to inform conservation management. Based on a year-round, multi-platform distance sampling dataset (2016-2021, 177 survey days, 754 groups observed), this study generated density models to describe and predict seasonal distribution of rorqual whales in Oregon. Phenology analysis of sightings revealed a peak of humpback whale and blue whale density over the Oregon continental shelf in August and September respectively, and higher fin whale density in the winter (December). Additionally, we compared rorqual sighting rates across three decades of survey effort (since 1989) and demonstrate that rorqual whales are strikingly more prevalent in the current dataset, including distinct increases of blue and fin whales. Finally, density surface models relating whale densities to static and dynamic environmental variables acquired from data-assimilative ocean models revealed that summer and spring rorqual distribution were influenced by dynamic oceanographic features indicative of active upwelling and frontal zones (respectively 27% and 40% deviance explained). On the continental shelf, blue whales were predicted to occur closer to shore than humpback whales and in the more southern waters off Oregon. Summer and spring rorqual models, and humpback whale models, showed predictive performance suitable for management purposes, assessed through internal cross-validation and comparison to an external dataset (388 groups observed). Indeed, monthly hotspots of high predicted rorqual whale density across multip

Published
2022
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14. Elastic and Inelastic Pion Scattering on 3H and 3He

Author

Berman, B. L., Dhuga, K. S., Briscoe, W. J., Matthews, S. K., Barlow, D. B., Nefkens, B. M. K., Pillai, C., Isenhower, L. D., Sadler, M. E., Greene, S. J., Slaus, I., Mitter, H., editor, Plessas, W., editor, Adam, J., editor, Dobeš, J., editor, Mach, R., editor, Sotona, M., editor, and Dolejší, J., editor

Published
1996
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29. Shock Ignition Laser-Plasma Interactions in Ignition-Scale Plasmas

Author

Scott, R. H. H., primary, Glize, K., additional, Antonelli, L., additional, Khan, M., additional, Theobald, W., additional, Wei, M., additional, Betti, R., additional, Stoeckl, C., additional, Seaton, A. G., additional, Arber, T. D., additional, Barlow, D., additional, Goffrey, T., additional, Bennett, K., additional, Garbett, W., additional, Atzeni, S., additional, Casner, A., additional, Batani, D., additional, Li, C., additional, and Woolsey, N., additional

Published
2021
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41. Effectiveness of the Unified Protocol for transdiagnostic treatment of emotional disorders in group format in Spain: Results from a randomized controlled trial with 6-months follow-up.

Author

Osma, J., Peris-Baquero, O., Suso-Ribera, C., Farchione, T. J., and Barlow, D. H.

Subjects
RANDOMIZED controlled trials, COGNITIVE therapy, MEDICAL protocols, MENTAL depression, MENTAL health
Abstract

The present study aims to investigate the effectiveness of the Unified Protocol (UP), a transdiagnostic treatment of emotional disorders (EDs), when applied in a group format in the public mental health system in Spain. 488 participants with a primary diagnosis of ED were randomized to the UP group or to the treatment as usual (TAU; individual, disorder-specific cognitive behavioral therapy). Personality, depression and anxiety symptoms, affect, and quality of life were assessed at pre-treatment, 3 months after treatment onset (coinciding with the end of the UP treatment), and 6 and 9 months after treatment onset (follow-ups). The moderating effect of the treatment condition and the number of sessions received in the evolution of study outcomes was investigated with a linear mixed model analysis. A significant improvement in outcomes occurred in both conditions, except for extraversion in the TAU. Improvements in depression, anxiety and quality of life were larger in the UP condition. After the treatment, improvements were maintained at follow-ups in all study outcomes. An interaction between Time*Condition*Sessions was found for depression. The results add to the existing evidence on the effectiveness of the UP and may be important for implementation purposes in the Spanish or other similar public mental health systems. Trial registration number NCT03064477 (March 10, 2017). [ABSTRACT FROM AUTHOR]

Published
2022
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