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510 results on '"Thomas, K. J."'

1. On the half life of $^{71}$Ge and the Gallium Anomaly

Author

Norman, E. B., Drobizhev, A., Gharibyan, N., Gregorich, K. E., Kolomensky, Yu. G., Sammis, B. N., Scielzo, N. D., Shusterman, J. A., and Thomas, K. J.

Subjects
Nuclear Experiment
Abstract

Recent discussions about the origin of the Gallium Anomaly have motivated a remeasurement of the half life of $^{71}$Ge. We have conducted three separate measurements using dedicated planar Ge detectors: one with $^{55}$Fe as a standard, one with $^{57}$Co as a standard, and one stand alone 71Ge measurement. Our results yield a half life of 11.468 +- 0.008 days, which is consistent with but significantly more precise than the currently accepted value. With this experiment, the potential explanation of the Gallium Anomaly being due to an unexpectedly long $^{71}$Ge half life has been ruled out, leaving the origin of the anomaly as an open question., Comment: 9 pages, 4 figures

Published
2024

2. First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

Author

Aalbers, J., Akerib, D. S., Akerlof, C. W., Musalhi, A. K. Al, Alder, F., Alqahtani, A., Alsum, S. K., Amarasinghe, C. S., Ames, A., Anderson, T. J., Angelides, N., Araújo, H. M., Armstrong, J. E., Arthurs, M., Azadi, S., Bailey, A. J., Baker, A., Balajthy, J., Balashov, S., Bang, J., Bargemann, J. W., Barry, M. J., Barthel, J., Bauer, D., Baxter, A., Beattie, K., Belle, J., Beltrame, P., Bensinger, J., Benson, T., Bernard, E. P., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birch, H. J., Birrittella, B., Blockinger, G. M., Boast, K. E., Boxer, B., Bramante, R., Brew, C. A. J., Brás, P., Buckley, J. H., Bugaev, V. V., Burdin, S., Busenitz, J. K., Buuck, M., Cabrita, R., Carels, C., Carlsmith, D. L., Carlson, B., Carmona-Benitez, M. C., Cascella, M., Chan, C., Chawla, A., Chen, H., Cherwinka, J. J., Chott, N. I., Cole, A., Coleman, J., Converse, M. V., Cottle, A., Cox, G., Craddock, W. W., Creaner, O., Curran, D., Currie, A., Cutter, J. E., Dahl, C. E., David, A., Davis, J., Davison, T. J. R., Delgaudio, J., Dey, S., de Viveiros, L., Dobi, A., Dobson, J. E. Y., Druszkiewicz, E., Dushkin, A., Edberg, T. K., Edwards, W. R., Elnimr, M. M., Emmet, W. T., Eriksen, S. R., Faham, C. H., Fan, A., Fayer, S., Fearon, N. M., Fiorucci, S., Flaecher, H., Ford, P., Francis, V. B., Fraser, E. D., Fruth, T., Gaitskell, R. J., Gantos, N. J., Garcia, D., Geffre, A., Gehman, V. M., Genovesi, J., Ghag, C., Gibbons, R., Gibson, E., Gilchriese, M. G. D., Gokhale, S., Gomber, B., Green, J., Greenall, A., Greenwood, S., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Hans, S., Hanzel, K., Harrison, A., Hartigan-O'Connor, E., Haselschwardt, S. J., Hertel, S. A., Heuermann, G., Hjemfelt, C., Hoff, M. D., Holtom, E., Hor, J. Y-K., Horn, M., Huang, D. Q., Hunt, D., Ignarra, C. M., Jacobsen, R. G., Jahangir, O., James, R. S., Jeffery, S. N., Ji, W., Johnson, J., Kaboth, A. C., Kamaha, A. C., Kamdin, K., Kasey, V., Kazkaz, K., Keefner, J., Khaitan, D., Khaleeq, M., Khazov, A., Khurana, I., Kim, Y. D., Kocher, C. D., Kodroff, D., Korley, L., Korolkova, E. V., Kras, J., Kraus, H., Kravitz, S., Krebs, H. J., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Kyre, S., Landerud, B., Leason, E. A., Lee, C., Lee, J., Leonard, D. S., Leonard, R., Lesko, K. T., Levy, C., Li, J., Liao, F. -T., Liao, J., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, R., Liu, X., Liu, Y., Loniewski, C., Lopes, M. I., Asamar, E. Lopez, Paredes, B. López, Lorenzon, W., Lucero, D., Luitz, S., Lyle, J. M., Majewski, P. A., Makkinje, J., Malling, D. C., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., Marzioni, M. F., Maupin, C., McCarthy, M. E., McConnell, C. T., McKinsey, D. N., McLaughlin, J., Meng, Y., Migneault, J., Miller, E. H., Mizrachi, E., Mock, J. A., Monte, A., Monzani, M. E., Morad, J. A., Mendoza, J. D. Morales, Morrison, E., Mount, B. J., Murdy, M., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nehrkorn, C., Neves, F., Nguyen, A., Nikoleyczik, J. A., Nilima, A., O'Dell, J., O'Neill, F. G., O'Sullivan, K., Olcina, I., Olevitch, M. A., Oliver-Mallory, K. C., Orpwood, J., Pagenkopf, D., Pal, S., Palladino, K. J., Palmer, J., Pangilinan, M., Parveen, N., Patton, S. J., Pease, E. K., Penning, B., Pereira, C., Pereira, G., Perry, E., Pershing, T., Peterson, I. B., Piepke, A., Podczerwinski, J., Porzio, D., Powell, S., Preece, R. M., Pushkin, K., Qie, Y., Ratcliff, B. N., Reichenbacher, J., Reichhart, L., Rhyne, C. A., Richards, A., Riffard, Q., Rischbieter, G. R. C., Rodrigues, J. P., Rodriguez, A., Rose, H. J., Rosero, R., Rossiter, P., Rushton, T., Rutherford, G., Rynders, D., Saba, J. S., Santone, D., Sazzad, A. B. M. R., Schnee, R. W., Scovell, P. R., Seymour, D., Shaw, S., Shutt, T., Silk, J. J., Silva, C., Sinev, G., Skarpaas, K., Skulski, W., Smith, R., Solmaz, M., Solovov, V. N., Sorensen, P., Soria, J., Stancu, I., Stark, M. R., Stevens, A., Stiegler, T. M., Stifter, K., Studley, R., Suerfu, B., Sumner, T. J., Sutcliffe, P., Swanson, N., Szydagis, M., Tan, M., Taylor, D. J., Taylor, R., Taylor, W. C., Temples, D. J., Tennyson, B. P., Terman, P. A., Thomas, K. J., Tiedt, D. R., Timalsina, M., To, W. H., Tomás, A., Tong, Z., Tovey, D. R., Tranter, J., Trask, M., Tripathi, M., Tronstad, D. R., Tull, C. E., Turner, W., Tvrznikova, L., Utku, U., Va'vra, J., Vacheret, A., Vaitkus, A. C., Verbus, J. R., Voirin, E., Waldron, W. L., Wang, A., Wang, B., Wang, J. J., Wang, W., Wang, Y., Watson, J. R., Webb, R. C., White, A., White, D. T., White, J. T., White, R. G., Whitis, T. J., Williams, M., Wisniewski, W. J., Witherell, M. S., Wolfs, F. L. H., Wolfs, J. D., Woodford, S., Woodward, D., Worm, S. D., Wright, C. J., Xia, Q., Xiang, X., Xiao, Q., Xu, J., Yeh, M., Yin, J., Young, I., Zarzhitsky, P., Zuckerman, A., and Zweig, E. A.

Subjects
High Energy Physics - Experiment, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60~live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c$^2$. The most stringent limit is set for spin-independent scattering at 36 GeV/c$^2$, rejecting cross sections above 9.2$\times 10^{-48}$ cm$^2$ at the 90% confidence level., Comment: 9 pages, 8 figures. See https://doi.org/10.1103/PhysRevLett.131.041002 for a data release related to this paper

Published
2022
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4. The LUX-ZEPLIN (LZ) radioactivity and cleanliness control programs

Author

Akerib, D. S., Akerlof, C. W., Akimov, D. Yu., Alquahtani, A., Alsum, S. K., Anderson, T. J., Angelides, N., Araújo, H. M., Arbuckle, A., Armstrong, J. E., Arthurs, M., Auyeung, H., Aviles, S., Bai, X., Bailey, A. J., Balajthy, J., Balashov, S., Bang, J., Barry, M. J., Bauer, D., Bauer, P., Baxter, A., Belle, J., Beltrame, P., Bensinger, J., Benson, T., Bernard, E. P., Bernstein, A., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birch, H. J., Birrittella, B., Boast, K. E., Bolozdynya, A. I., Boulton, E. M., Boxer, B., Bramante, R., Branson, S., Brás, P., Breidenbach, M., Brew, C. A. J., Buckley, J. H., Bugaev, V. V., Bunker, R., Burdin, S., Busenitz, J. K., Cabrita, R., Campbell, J. S., Carels, C., Carlsmith, D. L., Carlson, B., Carmona-Benitez, M. C., Cascella, M., Chan, C., Cherwinka, J. J., Chiller, A. A., Chiller, C., Chott, N. I., Cole, A., Coleman, J., Colling, D., Conley, R. A., Cottle, A., Coughlen, R., Cox, G., Craddock, W. W., Curran, D., Currie, A., Cutter, J. E., da Cunhaw, J. P., Dahl, C. E., Dardin, S., Dasu, S., Davis, J., Davison, T. J. R., de Viveiros, L., Decheine, N., Dobi, A., Dobson, J. E. Y., Druszkiewicz, E., Dushkin, A., Edberg, T. K., Edwards, W. R., Edwards, B. N., Edwards, J., Elnimr, M. M., Emmet, W. T., Eriksen, S. R., Faham, C. H., Fan, A., Fayer, S., Fiorucci, S., Flaecher, H., Florang, I. M. Fogarty, Ford, P., Francis, V. B., Fraser, E. D., Froborg, F., Fruth, T., Gaitskell, R. J., Gantos, N. J., Garcia, D., Gehman, V. M., Gelfand, R., Genovesi, J., Gerhard, R. M., Ghag, C., Gibson, E., Gilchriese, M. G. D., Gokhale, S., Gomber, B., Gonda, T. G., Greenall, A., Greenwood, S., Gregerson, G., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Hamilton, D., Hans, S., Hanzel, K., Harrington, T., Harrison, A., Harrison, J., Hasselkus, C., Haselschwardt, S. J., Hemer, D., Hertel, S. A., Heise, J., Hillbrand, S., Hitchcock, O., Hjemfelt, C., Hoff, M. D., Holbrook, B., Holtom, E., Hor, J. Y-K., Horn, M., Huang, D. Q., Hurteau, T. W., Ignarra, C. M., Irving, M. N., Jacobsen, R. G., Jahangir, O., Jeffery, S. N., Ji, W., Johnson, M., Johnson, J., Johnson, P., Jones, W. G., Kaboth, A. C., Kamaha, A., Kamdin, K., Kasey, V., Kazkaz, K., Keefner, J., Khaitan, D., Khaleeq, M., Khazov, A., Khromov, A. V., Khurana, I., Kim, Y. D., Kim, W. T., Kocher, C. D., Kodroff, D., Konovalov, A. M., Korley, L., Korolkova, E. V., Koyuncu, M., Kras, J., Kraus, H., Kravitz, S. W., Krebs, H. J., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Kumpan, A. V., Kyre, S., Lambert, A. R., Landerud, B., Larsen, N. A., Laundrie, A., Leason, E. A., Lee, H. S., Lee, J., Lee, C., Lenardo, B. G., Leonard, D. S., Leonard, R., Lesko, K. T., Levy, C., Li, J., Liu, Y., Liao, J., Liao, F. -T., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, R., Liu, X., Loniewski, C., Lopes, M. I., Lopez-Asamar, E., Paredes, B. López, Lorenzon, W., Lucero, D., Luitz, S., Lyle, J. M., Lynch, C., Majewski, P. A., Makkinje, J., Malling, D. C., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., Markley, D. J., MarrLaundrie, P., Martin, T. J., Marzioni, M. F., Maupin, C., McConnell, C. T., McKinsey, D. N., McLaughlin, J., Mei, D. -M., Meng, Y., Miller, E. H., Minaker, Z. J., Mizrachi, E., Mock, J., Molash, D., Monte, A., Monzani, M. E., Morad, J. A., Morrison, E., Mount, B. J., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nehrkorn, C., Nelson, H. N., Nesbit, J., Neves, F., Nikkel, J. A., Nikoleyczik, J. A., Nilima, A., O'Dell, J., Oh, H., O'Neill, F. G., O'Sullivan, K., Olcina, I., Olevitch, M. A., Oliver-Mallory, K. C., Oxborough, L., Pagac, A., Pagenkopf, D., Pal, S., Palladino, K. J., Palmaccio, V. M., Palmer, J., Pangilinan, M., Parveen, N., Patton, S. J., Pease, E. K., Penning, B. P., Pereira, G., Pereira, C., Peterson, I. B., Piepke, A., Pierson, S., Powell, S., Preece, R. M., Pushkin, K., Qie, Y., Racine, M., Ratcliff, B. N., Reichenbacher, J., Reichhart, L., Rhyne, C. A., Richards, A., Riffard, Q., Rischbieter, G. R. C., Rodrigues, J. P., Rose, H. J., Rosero, R., Rossiter, P., Rucinski, R., Rutherford, G., Saba, J. S., Sabarots, L., Santone, D., Sarychev, M., Sazzad, A. B. M. R., Schnee, R. W., Schubnell, M., Scovell, P. R., Severson, M., Seymour, D., Shaw, S., Shutt, G. W., Shutt, T. A., Silk, J. J., Silva, C., Skarpaas, K., Skulski, W., Smith, A. R., Smith, R. J., Smith, R. E., So, J., Solmaz, M., Solovov, V. N., Sorensen, P., Sosnovtsev, V. V., Stancu, I., Stark, M. R., Stephenson, S., Stern, N., Stevens, A., Stiegler, T. M., Stifter, K., Studley, R., Sumner, T. J., Sundarnath, K., Sutcliffe, P., Swanson, N., Szydagis, M., Tan, M., Taylor, W. C., Taylor, R., Taylor, D. J., Temples, D., Tennyson, B. P., Terman, P. A., Thomas, K. J., Thomson, J. A., Tiedt, D. R., Timalsina, M., To, W. H., Tomás, A., Tope, T. E., Tripathi, M., Tronstad, D. R., Tull, C. E., Turner, W., Tvrznikova, L., Utes, M., Utku, U., Uvarov, S., Va'vra, J., Vacheret, A., Vaitkus, A., Verbus, J. R., Vietanen, T., Voirin, E., Vuosalo, C. O., Walcott, S., Waldron, W. L., Walker, K., Wang, J. J., Wang, R., Wang, L., Wang, W., Wang, Y., Watson, J. R., Migneault, J., Weatherly, S., Webb, R. C., Wei, W. -Z., While, M., White, R. G., White, J. T., White, D. T., Whitis, T. J., Wisniewski, W. J., Wilson, K., Witherell, M. S., Wolfs, F. L. H., Wolfs, J. D., Woodward, D., Worm, S. D., Xiang, X., Xiao, Q., Xu, J., Yeh, M., Yin, J., Young, I., Zhang, C., and Zarzhitsky, P.

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

LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above $1.4 \times 10^{-48}$ cm$^{2}$ for a WIMP mass of 40 GeV/c$^{2}$ and a 1000 d exposure. LZ achieves this sensitivity through a combination of a large 5.6 t fiducial volume, active inner and outer veto systems, and radio-pure construction using materials with inherently low radioactivity content. The LZ collaboration performed an extensive radioassay campaign over a period of six years to inform material selection for construction and provide an input to the experimental background model against which any possible signal excess may be evaluated. The campaign and its results are described in this paper. We present assays of dust and radon daughters depositing on the surface of components as well as cleanliness controls necessary to maintain background expectations through detector construction and assembly. Finally, examples from the campaign to highlight fixed contaminant radioassays for the LZ photomultiplier tubes, quality control and quality assurance procedures through fabrication, radon emanation measurements of major sub-systems, and bespoke detector systems to assay scintillator are presented., Comment: 45 pages (79 inc. tables), 7 figures, 9 tables

Published
2020
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5. Absolute Decay Counting of 146147Sm and 146147Sm for Early Solar System Chronology

Author

Kim, G. B., Borg, L. E., Boyd, S. T. P., Cantor, R. H., Despotopulos, J. D., Drury, O. B., Friedrich, S., Gallant, A., Hines, N. R., Jacobs, A., Jovanovic, I., Kmak, K. N., Kavner, A. R. L., Kim, Y. H., Kunz, P., Kwiatkowski, A., Kwon, D. H., Lee, D., Murböck, T., Scielzo, N. D., Shollenberger, Q. R., Sio, C. K. I., Thomas, K. J., Wooddy, T., and Walls, C.

Published
2022
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6. The LUX-ZEPLIN (LZ) Experiment

Author

The LZ Collaboration, Akerib, D. S., Akerlof, C. W., Akimov, D. Yu., Alquahtani, A., Alsum, S. K., Anderson, T. J., Angelides, N., Araújo, H. M., Arbuckle, A., Armstrong, J. E., Arthurs, M., Auyeung, H., Bai, X., Bailey, A. J., Balajthy, J., Balashov, S., Bang, J., Barry, M. J., Barthel, J., Bauer, D., Bauer, P., Baxter, A., Belle, J., Beltrame, P., Bensinger, J., Benson, T., Bernard, E. P., Bernstein, A., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birrittella, B., Boast, K. E., Bolozdynya, A. I., Boulton, E. M., Boxer, B., Bramante, R., Branson, S., Brás, P., Breidenbach, M., Buckley, J. H., Bugaev, V. V., Bunker, R., Burdin, S., Busenitz, J. K., Campbell, J. S., Carels, C., Carlsmith, D. L., Carlson, B., Carmona-Benitez, M. C., Cascella, M., Chan, C., Cherwinka, J. J., Chiller, A. A., Chiller, C., Chott, N. I., Cole, A., Coleman, J., Colling, D., Conley, R. A., Cottle, A., Coughlen, R., Craddock, W. W., Curran, D., Currie, A., Cutter, J. E., da Cunha, J. P., Dahl, C. E., Dardin, S., Dasu, S., Davis, J., Davison, T. J. R., de Viveiros, L., Decheine, N., Dobi, A., Dobson, J. E. Y., Druszkiewicz, E., Dushkin, A., Edberg, T. K., Edwards, W. R., Edwards, B. N., Edwards, J., Elnimr, M. M., Emmet, W. T., Eriksen, S. R., Faham, C. H., Fan, A., Fayer, S., Fiorucci, S., Flaecher, H., Florang, I. M. Fogarty, Ford, P., Francis, V. B., Froborg, F., Fruth, T., Gaitskell, R. J., Gantos, N. J., Garcia, D., Geffre, A., Gehman, V. M., Gelfand, R., Genovesi, J., Gerhard, R. M., Ghag, C., Gibson, E., Gilchriese, M. G. D., Gokhale, S., Gomber, B., Gonda, T. G., Greenall, A., Greenwood, S., Gregerson, G., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Hamilton, D., Hans, S., Hanzel, K., Harrington, T., Harrison, A., Hasselkus, C., Haselschwardt, S. J., Hemer, D., Hertel, S. A., Heise, J., Hillbrand, S., Hitchcock, O., Hjemfelt, C., Hoff, M. D., Holbrook, B., Holtom, E., Hor, J. Y-K., Horn, M., Huang, D. Q., Hurteau, T. W., Ignarra, C. M., Irving, M. N., Jacobsen, R. G., Jahangir, O., Jeffery, S. N., Ji, W., Johnson, M., Johnson, J., Johnson, P., Jones, W. G., Kaboth, A. C., Kamaha, A., Kamdin, K., Kasey, V., Kazkaz, K., Keefner, J., Khaitan, D., Khaleeq, M., Khazov, A., Khromov, A. V., Khurana, I., Kim, Y. D., Kim, W. T., Kocher, C. D., Konovalov, A. M., Korley, L., Korolkova, E. V., Koyuncu, M., Kras, J., Kraus, H., Kravitz, S. W., Krebs, H. J., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Kumpan, A. V., Kyre, S., Lambert, A. R., Landerud, B., Larsen, N. A., Laundrie, A., Leason, E. A., Lee, H. S., Lee, J., Lee, C., Lenardo, B. G., Leonard, D. S., Leonard, R., Lesko, K. T., Levy, C., Li, J., Liu, Y., Liao, J., Liao, F. -T., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, R., Liu, X., Loniewski, C., Lopes, M. I., Paredes, B. López, Lorenzon, W., Lucero, D., Luitz, S., Lyle, J. M., Lynch, C., Majewski, P. A., Makkinje, J., Malling, D. C., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., Markley, D. J., MarrLaundrie, P., Martin, T. J., Marzioni, M. F., Maupin, C., McConnell, C. T., McKinsey, D. N., McLaughlin, J., Mei, D. -M., Meng, Y., Miller, E. H., Minaker, Z. J., Mizrachi, E., Mock, J., Molash, D., Monte, A., Monzani, M. E., Morad, J. A., Morrison, E., Mount, B. J., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nehrkorn, C., Nelson, H. N., Nesbit, J., Neves, F., Nikkel, J. A., Nikoleyczik, J. A., Nilima, A., O'Dell, J., Oh, H., O'Neill, F. G., O'Sullivan, K., Olcina, I., Olevitch, M. A., Oliver-Mallory, K. C., Oxborough, L., Pagac, A., Pagenkopf, D., Pal, S., Palladino, K. J., Palmaccio, V. M., Palmer, J., Pangilinan, M., Patton, S. J., Pease, E. K., Penning, B. P., Pereira, G., Pereira, C., Peterson, I. B., Piepke, A., Pierson, S., Powell, S., Preece, R. M., Pushkin, K., Qie, Y., Racine, M., Ratcliff, B. N., Reichenbacher, J., Reichhart, L., Rhyne, C. A., Richards, A., Riffard, Q., Rischbieter, G. R. C., Rodrigues, J. P., Rose, H. J., Rosero, R., Rossiter, P., Rucinski, R., Rutherford, G., Rynders, D., Saba, J. S., Sabarots, L., Santone, D., Sarychev, M., Sazzad, A. B. M. R., Schnee, R. W., Schubnell, M., Scovell, P. R., Severson, M., Seymour, D., Shaw, S., Shutt, G. W., Shutt, T. A., Silk, J. J., Silva, C., Skarpaas, K., Skulski, W., Smith, A. R., Smith, R. J., Smith, R. E., So, J., Solmaz, M., Solovov, V. N., Sorensen, P., Sosnovtsev, V. V., Stancu, I., Stark, M. R., Stephenson, S., Stern, N., Stevens, A., Stiegler, T. M., Stifter, K., Studley, R., Sumner, T. J., Sundarnath, K., Sutcliffe, P., Swanson, N., Szydagis, M., Tan, M., Taylor, W. C., Taylor, R., Taylor, D. J., Temples, D., Tennyson, B. P., Terman, P. A., Thomas, K. J., Thomson, J. A., Tiedt, D. R., Timalsina, M., To, W. H., Tomás, A., Tope, T. E., Tripathi, M., Tronstad, D. R., Tull, C. E., Turner, W., Tvrznikova, L., Utes, M., Utku, U., Uvarov, S., Va'vra, J., Vacheret, A., Vaitkus, A., Verbus, J. R., Vietanen, T., Voirin, E., Vuosalo, C. O., Walcott, S., Waldron, W. L., Walker, K., Wang, J. J., Wang, R., Wang, L., Wang, Y., Watson, J. R., Migneault, J., Weatherly, S., Webb, R. C., Wei, W. -Z., While, M., White, R. G., White, J. T., White, D. T., Whitis, T. J., Wisniewski, W. J., Wilson, K., Witherell, M. S., Wolfs, F. L. H., Wolfs, J. D., Woodward, D., Worm, S. D., Xiang, X., Xiao, Q., Xu, J., Yeh, M., Yin, J., Young, I., and Zhang, C.

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment
Abstract

We describe the design and assembly of the LUX-ZEPLIN experiment, a direct detection search for cosmic WIMP dark matter particles. The centerpiece of the experiment is a large liquid xenon time projection chamber sensitive to low energy nuclear recoils. Rejection of backgrounds is enhanced by a Xe skin veto detector and by a liquid scintillator Outer Detector loaded with gadolinium for efficient neutron capture and tagging. LZ is located in the Davis Cavern at the 4850' level of the Sanford Underground Research Facility in Lead, South Dakota, USA. We describe the major subsystems of the experiment and its key design features and requirements.

Published
2019
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7. The voice characterisation checklist: psychometric properties of a brief clinical assessment of voices as social agents

Author

Clementine J. Edwards, Oliver Owrid, Lucy Miller, Hassan Jafari, Richard Emsley, Mar Rus-Calafell, Thomas K. J. Craig, Moya Clancy, Hamish McLeod, Miriam Fornells-Ambrojo, Jeffrey McDonnell, Alice Montague, Mark Huckvale, Sandra Bucci, Gillian Haddock, Philippa Garety, and Thomas Ward

Subjects
psychosis, voice-hearing, characterisation, phenomenology, auditory hallucination, Psychiatry, RC435-571
Abstract

AimThere is growing interest in tailoring psychological interventions for distressing voices and a need for reliable tools to assess phenomenological features which might influence treatment response. This study examines the reliability and internal consistency of the Voice Characterisation Checklist (VoCC), a novel 10-item tool which assesses degree of voice characterisation, identified as relevant to a new wave of relational approaches.MethodsThe sample comprised participants experiencing distressing voices, recruited at baseline on the AVATAR2 trial between January 2021 and July 2022 (n = 170). Inter-rater reliability (IRR) and internal consistency analyses (Cronbach’s alpha) were conducted.ResultsThe majority of participants reported some degree of voice personification (94%) with high endorsement of voices as distinct auditory experiences (87%) with basic attributes of gender and age (82%). While most identified a voice intention (75%) and personality (76%), attribution of mental states (35%) to the voice (‘What are they thinking?’) and a known historical relationship (36%) were less common. The internal consistency of the VoCC was acceptable (10 items, α = 0.71). IRR analysis indicated acceptable to excellent reliability at the item-level for 9/10 items and moderate agreement between raters’ global (binary) classification of more vs. less highly characterised voices, κ = 0.549 (95% CI, 0.240–0.859), p

Published
2023
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8. On the frontlines

Author

Daniel Vila and Thomas K. J. McDermott

Subjects
COVID-19, Air quality, Race, Inequality, Public aspects of medicine, RA1-1270
Abstract

Abstract Recent literature has suggested a link between poor air quality and worse COVID-19 outcomes. In the United States, this link is particularly noteworthy because of residential sorting along ethnic lines within the US population; minorities are disproportionately exposed to health hazards, including air pollution. The impacts of the COVID-19 pandemic have also been disproportionately concentrated amongst minorities. We explore the association between air quality and COVID-19 outcomes, using county level data for the United States from the first wave of the pandemic in 2020, and test whether exposure to more polluted air can account for some of the observed disparities in COVID-19 outcomes among minorities.

Published
2022
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10. Projected WIMP sensitivity of the LUX-ZEPLIN (LZ) dark matter experiment

Author

Akerib, D. S., Akerlof, C. W., Alsum, S. K., Araújo, H. M., Arthurs, M., Bai, X., Bailey, A. J., Balajthy, J., Balashov, S., Bauer, D., Belle, J., Beltrame, P., Benson, T., Bernard, E. P., Biesiadzinski, T. P., Boast, K. E., Boxer, B., Brás, P., Buckley, J. H., Bugaev, V. V., Burdin, S., Busenitz, J. K., Carels, C., Carlsmith, D. L., Carlson, B., Carmona-Benitez, M. C., Chan, C., Cherwinka, J. J., Cole, A., Cottle, A., Craddock, W. W., Currie, A., Cutter, J. E., Dahl, C. E., de Viveiros, L., Dobi, A., Dobson, J. E. Y., Druszkiewicz, E., Edberg, T. K., Edwards, W. R., Fan, A., Fayer, S., Fiorucci, S., Fruth, T., Gaitskell, R. J., Genovesi, J., Ghag, C., Gilchriese, M. G. D., van der Grinten, M. G. D., Hall, C. R., Hans, S., Hanzel, K., Haselschwardt, S. J., Hertel, S. A., Hillbrand, S., Hjemfelt, C., Hoff, M. D., Hor, J. Y-K., Huang, D. Q., Ignarra, C. M., Ji, W., Kaboth, A. C., Kamdin, K., Keefner, J., Khaitan, D., Khazov, A., Kim, Y. D., Kocher, C. D., Korolkova, E. V., Kraus, H., Krebs, H. J., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Kyre, S., Lee, J., Lenardo, B. G., Leonard, D. S., Lesko, K. T., Levy, C., Li, J., Liao, J., Liao, F. -T., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, X., Lopes, M. I., Paredes, B. López, Lorenzon, W., Luitz, S., Lyle, J. M., Majewski, P., Manalaysay, A., Mannino, R. L., Maupin, C., McKinsey, D. N., Meng, Y., Miller, E. H., Mock, J., Monzani, M. E., Morad, J. A., Morrison, E., Mount, B. J., Murphy, A. St. J., Nelson, H. N., Neves, F., Nikoleyczik, J., O'Sullivan, K., Olcina, I., Olevitch, M. A., Oliver-Mallory, K. C., Palladino, K. J., Patton, S. J., Pease, E. K., Penning, B., Piepke, A., Powell, S., Preece, R. M., Pushkin, K., Ratcliff, B. N., Reichenbacher, J., Rhyne, C. A., Richards, A., Rodrigues, J. P., Rosero, R., Rossiter, P., Saba, J. S., Sarychev, M., Schnee, R. W., Schubnell, M., Scovell, P. R., Shaw, S., Shutt, T. A., Silk, J. J., Silva, C., Skarpaas, K., Skulski, W., Solmaz, M., Solovov, V. N., Sorensen, P., Stancu, I., Stark, M. R., Stiegler, T. M., Stifter, K., Szydagis, M., Taylor, W. C., Taylor, R., Taylor, D. J., Temples, D., Terman, P. A., Thomas, K. J., Timalsina, M., To, W. H., Tomás, A., Tope, T. E., Tripathi, M., Tull, C. E., Tvrznikova, L., Utku, U., Va'vra, J., Vacheret, A., Verbus, J. R., Voirin, E., Waldron, W. L., Watson, J. R., Webb, R. C., White, D. T., Whitis, T. J., Wisniewski, W. J., Witherell, M. S., Wolfs, F. L. H., Woodward, D., Worm, S. D., Yeh, M., Yin, J., and Young, I.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

LUX-ZEPLIN (LZ) is a next generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7~tonnes, LZ will search primarily for low-energy interactions with Weakly Interacting Massive Particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000~live day run using a 5.6~tonne fiducial mass, LZ is projected to exclude at 90\% confidence level spin-independent WIMP-nucleon cross sections above $1.4 \times 10^{-48}$~cm$^{2}$ for a 40~$\mathrm{GeV}/c^{2}$ mass WIMP. Additionally, a $5\sigma$ discovery potential is projected reaching cross sections below the exclusion limits of recent experiments. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of $2.3 \times 10^{-43}$~cm$^{2}$ ($7.1 \times 10^{-42}$~cm$^{2}$) for a 40~$\mathrm{GeV}/c^{2}$ mass WIMP is expected. With underground installation well underway, LZ is on track for commissioning at SURF in 2020., Comment: 14 pages, 11 figures

Published
2018
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11. Global exposure to flood risk and poverty

Author

Thomas K. J. McDermott

Subjects
Science
Abstract

Flooding is a pervasive natural hazard, with new research demonstrating that more than one in five people around the world live in areas directly exposed to 1-in-100 year flood risk. Exposure to such flood risk is particularly concentrated amongst lower income households worldwide.

Published
2022
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12. LUX-ZEPLIN (LZ) Technical Design Report

Author

Mount, B. J., Hans, S., Rosero, R., Yeh, M., Chan, C., Gaitskell, R. J., Huang, D. Q., Makkinje, J., Malling, D. C., Pangilinan, M., Rhyne, C. A., Taylor, W. C., Verbus, J. R., Kim, Y. D., Lee, H. S., Lee, J., Leonard, D. S., Li, J., Belle, J., Cottle, A., Lippincott, W. H., Markley, D. J., Martin, T. J., Sarychev, M., Tope, T. E., Utes, M., Wang, R., Young, I., Araújo, H. M., Bailey, A. J., Bauer, D., Colling, D., Currie, A., Fayer, S., Froborg, F., Greenwood, S., Jones, W. G., Kasey, V., Khaleeq, M., Olcina, I., Paredes, B. López, Richards, A., Sumner, T. J., Tomás, A., Vacheret, A., Brás, P., Lindote, A., Lopes, M. I., Neves, F., Rodrigues, J. P., Silva, C., Solovov, V. N., Barry, M. J., Cole, A., Dobi, A., Edwards, W. R., Faham, C. H., Fiorucci, S., Gantos, N. J., Gehman, V. M., Gilchriese, M. G. D., Hanzel, K., Hoff, M. D., Kamdin, K., Lesko, K. T., McConnell, C. T., O'Sullivan, K., Oliver-Mallory, K. C., Patton, S. J., Saba, J. S., Sorensen, P., Thomas, K. J., Tull, C. E., Waldron, W. L., Witherell, M. S., Bernstein, A., Kazkaz, K., Xu, J., Akimov, D. Yu., Bolozdynya, A. I., Khromov, A. V., Konovalov, A. M., Kumpan, A. V., Sosnovtsev, V. V., Dahl, C. E., Temples, D., Carmona-Benitez, M. C., de Viveiros, L., Akerib, D. S., Auyeung, H., Biesiadzinski, T. P., Breidenbach, M., Bramante, R., Conley, R., Craddock, W. W., Fan, A., Hau, A., Ignarra, C. M., Ji, W., Krebs, H. J., Linehan, R., Lee, C., Luitz, S., Mizrachi, E., Monzani, M. E., O'Neill, F. G., Pierson, S., Racine, M., Ratcliff, B. N., Shutt, G. W., Shutt, T. A., Skarpaas, K., Stifter, K., To, W. H., Va'vra, J., Whitis, T. J., Wisniewski, W. J., Bai, X., Bunker, R., Coughlen, R., Hjemfelt, C., Leonard, R., Miller, E. H., Morrison, E., Reichenbacher, J., Schnee, R. W., Stark, M. R., Sundarnath, K., Tiedt, D. R., Timalsina, M., Bauer, P., Carlson, B., Horn, M., Johnson, M., Keefner, J., Maupin, C., Taylor, D. J., Balashov, S., Ford, P., Francis, V., Holtom, E., Khazov, A., Kaboth, A., Majewski, P., Nikkel, J. A., O'Dell, J., Preece, R. M., van der Grinten, M. G. D., Worm, S. D., Mannino, R. L., Stiegler, T. M., Terman, P. A., Webb, R. C., Levy, C., Mock, J., Szydagis, M., Busenitz, J. K., Elnimr, M., Hor, J. Y-K., Meng, Y., Piepke, A., Stancu, I., Kreczko, L., Krikler, B., Penning, B., Bernard, E. P., Jacobsen, R. G., McKinsey, D. N., Watson, R., Cutter, J. E., El-Jurf, S., Gerhard, R. M., Hemer, D., Hillbrand, S., Holbrook, B., Lenardo, B. G., Manalaysay, A. G., Morad, J. A., Stephenson, S., Thomson, J. A., Tripathi, M., Uvarov, S., Haselschwardt, S. J., Kyre, S., Nehrkorn, C., Nelson, H. N., Solmaz, M., White, D. T., Cascella, M., Dobson, J. E. Y., Ghag, C., Liu, X., Manenti, L., Reichhart, L., Shaw, S., Utku, U., Beltrame, P., Davison, T. J. R., Marzioni, M. F., Murphy, A. St. J., Nilima, A., Boxer, B., Burdin, S., Greenall, A., Powell, S., Rose, H. J., Sutcliffe, P., Balajthy, J., Edberg, T. K., Hall, C. R., Silk, J. S., Hertel, S., Akerlof, C. W., Arthurs, M., Lorenzon, W., Pushkin, K., Schubnell, M., Boast, K. E., Carels, C., Fruth, T., Kraus, H., Liao, F. -T., Lin, J., Scovell, P. R., Druszkiewicz, E., Khaitan, D., Koyuncu, M., Skulski, W., Wolfs, F. L. H., Yin, J., Korolkova, E. V., Kudryavtsev, V. A., Rossiter, P., Woodward, D., Chiller, A. A., Chiller, C., Mei, D. -M., Wang, L., Wei, W. -Z., While, M., Zhang, C., Alsum, S. K., Benson, T., Carlsmith, D. L., Cherwinka, J. J., Dasu, S., Gregerson, G., Gomber, B., Pagac, A., Palladino, K. J., Vuosalo, C. O., Xiao, Q., Buckley, J. H., Bugaev, V. V., Olevitch, M. A., Boulton, E. M., Emmet, W. T., Hurteau, T. W., Larsen, N. A., Pease, E. K., Tennyson, B. P., and Tvrznikova, L.

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment
Abstract

In this Technical Design Report (TDR) we describe the LZ detector to be built at the Sanford Underground Research Facility (SURF). The LZ dark matter experiment is designed to achieve sensitivity to a WIMP-nucleon spin-independent cross section of three times ten to the negative forty-eighth square centimeters., Comment: 392 pages. Submitted to the Department of Energy as part of the documentation for the Critical Decision Numbers Two and Three (CD-2 and CD-3) management processes. Report also available by chapter at this URL

Published
2017

13. Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches

Author

Akerib, D. S., Akerlof, C. W., Akimov, D. Yu., Alsum, S. K., Araújo, H. M., Arnquist, I. J., Arthurs, M., Bai, X., Bailey, A. J., Balajthy, J., Balashov, S., Barry, M. J., Belle, J., Beltrame, P., Benson, T., Bernard, E. P., Bernstein, A., Biesiadzinski, T. P., Boast, K. E., Bolozdynya, A., Boxer, B., Bramante, R., Brás, P., Buckley, J. H., Bugaev, V. V., Bunker, R., Burdin, S., Busenitz, J. K., Carels, C., Carlsmith, D. L., Carlson, B., Carmona-Benitez, M. C., Chan, C., Cherwinka, J. J., Chiller, A. A., Chiller, C., Cottle, A., Coughlen, R., Craddock, W. W., Currie, A., Dahl, C. E., Davison, T. J. R., Dobi, A., Dobson, J. E. Y., Druszkiewicz, E., Edberg, T. K., Edwards, W. R., Emmet, W. T., Faham, C. H., Fiorucci, S., Fruth, T., Gaitskell, R. J., Gantos, N. J., Gehman, V. M., Gerhard, R. M., Ghag, C., Gilchriese, M. G. D., Gomber, B., Hall, C. R., Hans, S., Hanzel, K., Haselschwardt, S. J., Hertel, S. A., Hillbrand, S., Hjemfelt, C., Hoff, M. D., Holbrook, B., Holtom, E., Hoppe, E. W., Hor, J. Y-K., Horn, M., Huang, D. Q., Hurteau, T. W., Ignarra, C. M., Jacobsen, R. G., Ji, W., Kaboth, A., Kamdin, K., Kazkaz, K., Khaitan, D., Khazov, A., Khromov, A. V., Konovalov, A. M., Korolkova, E. V., Koyuncu, M., Kraus, H., Krebs, H. J., Kudryavtsev, V. A., Kumpan, A. V., Kyre, S., Lee, C., Lee, H. S., Lee, J., Leonard, D. S., Leonard, R., Lesko, K. T., Levy, C., Liao, F. -T., Lin, J., Lindote, A., Linehan, R. E., Lippincott, W. H., Liu, X., Lopes, M. I., Paredes, B. Lopez, Lorenzon, W., Luitz, S., Majewski, P., Manalaysay, A., Manenti, L., Mannino, R. L., Markley, D. J., Martin, T. J., Marzioni, M. F., McConnell, C. T., McKinsey, D. N., Mei, D. -M., Meng, Y., Miller, E. H., Mizrachi, E., Mock, J., Monzani, M. E., Morad, J. A., Mount, B. J., Murphy, A. St. J., Nehrkorn, C., Nelson, H. N., Neves, F., Nikkel, J. A., O'Dell, J., O'Sullivan, K., Olcina, I., Olevitch, M. A., Oliver-Mallory, K. C., Palladino, K. J., Pease, E. K., Piepke, A., Powell, S., Preece, R. M., Pushkin, K., Ratcliff, B. N., Reichenbacher, J., Reichhart, L., Rhyne, C. A., Richards, A., Rodrigues, J. P., Rose, H. J., Rosero, R., Rossiter, P., Saba, J. S., Sarychev, M., Schnee, R. W., Schubnell, M., Scovell, P. R., Shaw, S., Shutt, T. A., Silva, C., Skarpaas, K., Skulski, W., Solmaz, M., Solovov, V. N., Sorensen, P., Sosnovtsev, V. V., Stancu, I., Stark, M. R., Stephenson, S., Stiegler, T. M., Stifter, K., Sumner, T. J., Szydagis, M., Taylor, D. J., Taylor, W. C., Temples, D., Terman, P. A., Thomas, K. J., Thomson, J. A., Tiedt, D. R., Timalsina, M., To, W. H., Tomás, A., Tope, T. E., Tripathi, M., Tvrznikova, L., Va'vra, J., Vacheret, A., van der Grinten, M. G. D., Verbus, J. R., Vuosalo, C. O., Waldron, W. L., Wang, R., Watson, R., Webb, R. C., Wei, W. -Z., While, M., White, D. T., Whitis, T. J., Wisniewski, W. J., Witherell, M. S., Wolfs, F. L. H., Woodward, D., Worm, S., Xu, J., Yeh, M., Yin, J., and Zhang, C.

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

The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of $^{238}$U$_{e}$~$<$1.6~mBq/kg, $^{238}$U$_{l}$~$<$0.09~mBq/kg, $^{232}$Th$_{e}$~$=0.28\pm 0.03$~mBq/kg, $^{232}$Th$_{l}$~$=0.25\pm 0.02$~mBq/kg, $^{40}$K~$<$0.54~mBq/kg, and $^{60}$Co~$<$0.02~mBq/kg (68\% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of $0.160\pm0.001$(stat)$\pm0.030$(sys) counts., Comment: 13 pages, 3 figures, accepted for publication in Astroparticle Physics

Published
2017
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15. Flooded Cities

Author

Kocornik-Mina, Adriana, McDermott, Thomas K. J., Michaels, Guy, and Rauch, Ferdinand

Published
2020

16. LUX-ZEPLIN (LZ) Conceptual Design Report

Author

The LZ Collaboration, Akerib, D. S., Akerlof, C. W., Akimov, D. Yu., Alsum, S. K., Araújo, H. M., Bai, X., Bailey, A. J., Balajthy, J., Balashov, S., Barry, M. J., Bauer, P., Beltrame, P., Bernard, E. P., Bernstein, A., Biesiadzinski, T. P., Boast, K. E., Bolozdynya, A. I., Boulton, E. M., Bramante, R., Buckley, J. H., Bugaev, V. V., Bunker, R., Burdin, S., Busenitz, J. K., Carels, C., Carlsmith, D. L., Carlson, B., Carmona-Benitez, M. C., Cascella, M., Chan, C., Cherwinka, J. J., Chiller, A. A., Chiller, C., Craddock, W. W., Currie, A., Cutter, J. E., da Cunha, J. P., Dahl, C. E., Dasu, S., Davison, T. J. R., de Viveiros, L., Dobi, A., Dobson, J. E. Y., Druszkiewicz, E., Edberg, T. K., Edwards, B. N., Edwards, W. R., Elnimr, M. M., Emmet, W. T., Faham, C. H., Fiorucci, S., Ford, P., Francis, V. B., Fu, C., Gaitskell, R. J., Gantos, N. J., Gehman, V. M., Gerhard, R. M., Ghag, C., Gilchriese, M. G. D., Gomber, B., Hall, C. R., Harris, A., Haselschwardt, S. J., Hertel, S. A., Hoff, M. D., Holbrook, B., Holtom, E., Huang, D. Q., Hurteau, T. W., Ignarra, C. M., Jacobsen, R. G., Ji, W., Ji, X., Johnson, M., Ju, Y., Kamdin, K., Kazkaz, K., Khaitan, D., Khazov, A., Khromov, A. V., Konovalov, A. M., Korolkova, E. V., Kraus, H., Krebs, H. J., Kudryavtsev, V. A., Kumpan, A. V., Kyre, S., Larsen, N. A., Lee, C., Lenardo, B. G., Lesko, K. T., Liao, F. -T., Lin, J., Lindote, A., Lippincott, W. H., Liu, J., Liu, X., Lopes, M. I., Lorenzon, W., Luitz, S., Majewski, P., Malling, D. C., Manalaysay, A. G., Manenti, L., Mannino, R. L., Markley, D. J., Martin, T. J., Marzioni, M. F., McKinsey, D. N., Mei, D. -M., Meng, Y., Miller, E. H., Mock, J., Monzani, M. E., Morad, J. A., Murphy, A. St. J., Nelson, H. N., Neves, F., Nikkel, J. A., O'Neill, F. G., O'Dell, J., O'Sullivan, K., Olevitch, M. A., Oliver-Mallory, K. C., Palladino, K. J., Pangilinan, M., Patton, S. J., Pease, E. K., Piepke, A., Powell, S., Preece, R. M., Pushkin, K., Ratcliff, B. N., Reichenbacher, J., Reichhart, L., Rhyne, C., Rodrigues, J. P., Rose, H. J., Rosero, R., Saba, J. S., Sarychev, M., Schnee, R. W., Schubnell, M. S. G., Scovell, P. R., Shaw, S., Shutt, T. A., Silva, C., Skarpaas, K., Skulski, W., Solovov, V. N., Sorensen, P., Sosnovtsev, V. V., Stancu, I., Stark, M. R., Stephenson, S., Stiegler, T. M., Sumner, T. J., Sundarnath, K., Szydagis, M., Taylor, D. J., Taylor, W., Tennyson, B. P., Terman, P. A., Thomas, K. J., Thomson, J. A., Tiedt, D. R., To, W. H., Tomás, A., Tripathi, M., Tull, C. E., Tvrznikova, L., Uvarov, S., Va'vra, J., van der Grinten, M. G. D., Verbus, J. R., Vuosalo, C. O., Waldron, W. L., Wang, L., Webb, R. C., Wei, W. -Z., While, M., White, D. T., Whitis, T. J., Wisniewski, W. J., Witherell, M. S., Wolfs, F. L. H., Woods, E., Woodward, D., Worm, S. D., Yeh, M., Yin, J., Young, S. K., and Zhang, C.

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment
Abstract

The design and performance of the LUX-ZEPLIN (LZ) detector is described as of March 2015 in this Conceptual Design Report. LZ is a second-generation dark-matter detector with the potential for unprecedented sensitivity to weakly interacting massive particles (WIMPs) of masses from a few GeV/c2 to hundreds of TeV/c2. With total liquid xenon mass of about 10 tonnes, LZ will be the most sensitive experiment for WIMPs in this mass region by the end of the decade. This report describes in detail the design of the LZ technical systems. Expected backgrounds are quantified and the performance of the experiment is presented. The LZ detector will be located at the Sanford Underground Research Facility in South Dakota. The organization of the LZ Project and a summary of the expected cost and current schedule are given., Comment: 278 pages. Submitted to the Department of Energy as part of the documentation for the Critical Decision Number One (CD-1) management process. Report also available by chapter at http://hep.ucsb.edu/LZ/CDR. This version includes corrections of minor typographic errors

Published
2015

17. Erratum to: The LUX-ZEPLIN (LZ) radioactivity and cleanliness control programs

Author

Akerib, D. S., Akerlof, C. W., Akimov, D. Yu., Alquahtani, A., Alsum, S. K., Anderson, T. J., Angelides, N., Araújo, H. M., Arbuckle, A., Armstrong, J. E., Arthurs, M., Auyeung, H., Aviles, S., Bai, X., Bailey, A. J., Balajthy, J., Balashov, S., Bang, J., Barry, M. J., Bauer, D., Bauer, P., Baxter, A., Belle, J., Beltrame, P., Bensinger, J., Benson, T., Bernard, E. P., Bernstein, A., Bhatti, A., Biekert, A., Biesiadzinski, T. P., Birch, H. J., Birrittella, B., Boast, K. E., Bolozdynya, A. I., Boulton, E. M., Boxer, B., Bramante, R., Branson, S., Brás, P., Breidenbach, M., Brew, C. A. J., Buckley, J. H., Bugaev, V. V., Bunker, R., Burdin, S., Busenitz, J. K., Cabrita, R., Campbell, J. S., Carels, C., Carlsmith, D. L., Carlson, B., Carmona-Benitez, M. C., Cascella, M., Chan, C., Cherwinka, J. J., Chiller, A. A., Chiller, C., Chott, N. I., Cole, A., Coleman, J., Colling, D., Conley, R. A., Cottle, A., Coughlen, R., Cox, G., Craddock, W. W., Curran, D., Currie, A., Cutter, J. E., da Cunha, J. P., Dahl, C. E., Dardin, S., Dasu, S., Davis, J., Davison, T. J. R., de Viveiros, L., Decheine, N., Dobi, A., Dobson, J. E. Y., Druszkiewicz, E., Dushkin, A., Edberg, T. K., Edwards, W. R., Edwards, B. N., Edwards, J., Elnimr, M. M., Emmet, W. T., Eriksen, S. R., Faham, C. H., Fan, A., Fayer, S., Fiorucci, S., Flaecher, H., Florang, I. M. Fogarty, Ford, P., Francis, V. B., Fraser, E. D., Froborg, F., Fruth, T., Gaitskell, R. J., Gantos, N. J., Garcia, D., Gehman, V. M., Gelfand, R., Genovesi, J., Gerhard, R. M., Ghag, C., Gibson, E., Gilchriese, M. G. D., Gokhale, S., Gomber, B., Gonda, T. G., Greenall, A., Greenwood, S., Gregerson, G., van der Grinten, M. G. D., Gwilliam, C. B., Hall, C. R., Hamilton, D., Hans, S., Hanzel, K., Harrington, T., Harrison, A., Harrison, J., Hasselkus, C., Haselschwardt, S. J., Hemer, D., Hertel, S. A., Heise, J., Hillbrand, S., Hitchcock, O., Hjemfelt, C., Hoff, M. D., Holbrook, B., Holtom, E., Hor, J. Y-K., Horn, M., Huang, D. Q., Hurteau, T. W., Ignarra, C. M., Irving, M. N., Jacobsen, R. G., Jahangir, O., Jeffery, S. N., Ji, W., Johnson, M., Johnson, J., Johnson, P., Jones, W. G., Kaboth, A. C., Kamaha, A., Kamdin, K., Kasey, V., Kazkaz, K., Keefner, J., Khaitan, D., Khaleeq, M., Khazov, A., Khromov, A. V., Khurana, I., Kim, Y. D., Kim, W. T., Kocher, C. D., Kodroff, D., Konovalov, A. M., Korley, L., Korolkova, E. V., Koyuncu, M., Kras, J., Kraus, H., Kravitz, S. W., Krebs, H. J., Kreczko, L., Krikler, B., Kudryavtsev, V. A., Kumpan, A. V., Kyre, S., Lambert, A. R., Landerud, B., Larsen, N. A., Laundrie, A., Leason, E. A., Lee, H. S., Lee, J., Lee, C., Lenardo, B. G., Leonard, D. S., Leonard, R., Lesko, K. T., Levy, C., Li, J., Liu, Y., Liao, J., Liao, F.-T., Lin, J., Lindote, A., Linehan, R., Lippincott, W. H., Liu, R., Liu, X., Loniewski, C., Lopes, M. I., Lopez-Asamar, E., Paredes, B. López, Lorenzon, W., Lucero, D., Luitz, S., Lyle, J. M., Lynch, C., Majewski, P. A., Makkinje, J., Malling, D. C., Manalaysay, A., Manenti, L., Mannino, R. L., Marangou, N., Markley, D. J., MarrLaundrie, P., Martin, T. J., Marzioni, M. F., Maupin, C., McConnell, C. T., McKinsey, D. N., McLaughlin, J., Mei, D.-M., Meng, Y., Miller, E. H., Minaker, Z. J., Mizrachi, E., Mock, J., Molash, D., Monte, A., Monzani, M. E., Morad, J. A., Morrison, E., Mount, B. J., Murphy, A. St. J., Naim, D., Naylor, A., Nedlik, C., Nehrkorn, C., Nelson, H. N., Nesbit, J., Neves, F., Nikkel, J. A., Nikoleyczik, J. A., Nilima, A., O’Dell, J., Oh, H., O’Neill, F. G., O’Sullivan, K., Olcina, I., Olevitch, M. A., Oliver-Mallory, K. C., Oxborough, L., Pagac, A., Pagenkopf, D., Pal, S., Palladino, K. J., Palmaccio, V. M., Palmer, J., Pangilinan, M., Parveen, N., Patton, S. J., Pease, E. K., Penning, B. P., Pereira, G., Pereira, C., Peterson, I. B., Piepke, A., Pierson, S., Powell, S., Preece, R. M., Pushkin, K., Qie, Y., Racine, M., Ratcliff, B. N., Reichenbacher, J., Reichhart, L., Rhyne, C. A., Richards, A., Riffard, Q., Rischbieter, G. R. C., Rodrigues, J. P., Rose, H. J., Rosero, R., Rossiter, P., Rucinski, R., Rutherford, G., Saba, J. S., Sabarots, L., Santone, D., Sarychev, M., Sazzad, A. B. M. R., Schnee, R. W., Schubnell, M., Scovell, P. R., Severson, M., Seymour, D., Shaw, S., Shutt, G. W., Shutt, T. A., Silk, J. J., Silva, C., Skarpaas, K., Skulski, W., Smith, A. R., Smith, R. J., Smith, R. E., So, J., Solmaz, M., Solovov, V. N., Sorensen, P., Sosnovtsev, V. V., Stancu, I., Stark, M. R., Stephenson, S., Stern, N., Stevens, A., Stiegler, T. M., Stifter, K., Studley, R., Sumner, T. J., Sundarnath, K., Sutcliffe, P., Swanson, N., Szydagis, M., Tan, M., Taylor, W. C., Taylor, R., Taylor, D. J., Temples, D., Tennyson, B. P., Terman, P. A., Thomas, K. J., Thomson, J. A., Tiedt, D. R., Timalsina, M., To, W. H., Tomás, A., Tope, T. E., Tripathi, M., Tronstad, D. R., Tull, C. E., Turner, W., Tvrznikova, L., Utes, M., Utku, U., Uvarov, S., Va’vra, J., Vacheret, A., Vaitkus, A., Verbus, J. R., Vietanen, T., Voirin, E., Vuosalo, C. O., Walcott, S., Waldron, W. L., Walker, K., Wang, J. J., Wang, R., Wang, L., Wang, W., Wang, Y., Watson, J. R., Migneault, J., Weatherly, S., Webb, R. C., Wei, W.-Z., While, M., White, R. G., White, J. T., White, D. T., Whitis, T. J., Wisniewski, W. J., Wilson, K., Witherell, M. S., Wolfs, F. L. H., Wolfs, J. D., Woodward, D., Worm, S. D., Xiang, X., Xiao, Q., Xu, J., Yeh, M., Yin, J., Young, I., Zhang, C., and Zarzhitsky, P.

Published
2022
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18. MBE growth of Ge1− x Sn x devices with intrinsic disorder.

Author

Holmes, S N, Gul, Y, Pullen, I, Gough, J, Thomas, K J, Jia, H, Tang, M, Liu, H, and Pepper, M

Subjects
QUANTUM well devices, MOLECULAR beam epitaxy, PLANCK'S constant, QUANTUM wells, CARRIER density, HALL effect, EPITAXY, SURFACE segregation
Abstract

We discuss the electrical properties of molecular beam epitaxy (MBE) grown, modulation doped, Ge1− x Sn x quantum well devices. A consequence of the epitaxial growth process is that electronic disorder is introduced even in modulation doped quantum well structures and electrical transport properties that are characteristic of a high level of disorder are apparent. MBE growth of this material also results in the surface segregation of elemental β -Sn in the way that has been observed utilizing other epitaxial growth methods. A thermally activated, p-type mobility is a clear feature of the electrical properties with generally temperature independent hole densities ∼1012 cm−2 from the measured Hall effect and coming from the modulation doping. We present a discussion of Hall effect measurements in this disordered regime. The percolation carrier density in MBE modulation doped GeSn is in the region of ∼1 × 1012 cm−2 although Hall measurements in this regime are difficult to quantify when the resistivity >(h / e 2). In this notation h is Planck's constant and e is the unit of charge. Conductivities (σ) as low as ∼0.028 × (e 2/ h) × square can be measured in the four-contact ac configuration and the temperature dependence indicates a mobility edge in these p-type devices below ∼2 × 1012 cm−2. At lower temperatures (<∼1 K) the presence of a Coulomb gap can be determined using dc transport, constant voltage measurements where small ac current excitation is not available experimentally. This two-contact configuration can determine σ down to ∼10−6 × (e 2/ h), deep into the localization regime, revealing a hopping conductivity dominated system. We discuss the relevance of these electrical properties for MBE grown GeSn devices. [ABSTRACT FROM AUTHOR]

Published
2024
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19. The effect of split gate size on the electrostatic potential and 0.7 anomaly within one-dimensional quantum wires on a modulation doped GaAs/AlGaAs heterostructure

Author

Smith, L. W., Al-Taie, H., Lesage, A. A. J., Thomas, K. J., Sfigakis, F., See, P., Griffiths, J. P., Farrer, I., Jones, G. A. C., Ritchie, D. A., Kelly, M. J., and Smith, C. G.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We study 95 split gates of different size on a single chip using a multiplexing technique. Each split gate defines a one-dimensional channel on a modulation-doped GaAs/AlGaAs heterostructure, through which the conductance is quantized. The yield of devices showing good quantization decreases rapidly as the length of the split gates increases. However, for the subset of devices showing good quantization, there is no correlation between the electrostatic length of the one dimensional channel (estimated using a saddle point model), and the gate length. The variation in electrostatic length and the one-dimensional subband spacing for devices of the same gate length exceeds the variation in the average values between devices of different length. There is a clear correlation between the curvature of the potential barrier in the transport direction and the strength of the "0.7 anomaly": the conductance value of the 0.7 anomaly reduces as the barrier curvature becomes shallower. These results highlight the key role of the electrostatic environment in one-dimensional systems. Even in devices with clean conductance plateaus, random fluctuations in the background potential are crucial in determining the potential landscape in the active device area such that nominally identical gate structures have different characteristics.

Published
2015
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20. Measurements of Fission Products from the Fukushima Daiichi Incident in San Francisco Bay Area Air Filters, Automobile Filters, Rainwater, and Food

Author

Smith, A. R., Thomas, K. J., Norman, E. B., Hurley, D. L., Lo, B. T., Chan, Y. D., Guillaumon, P. V., and Harvey, B. G.

Subjects
Nuclear Experiment
Abstract

A variety of environmental media were analyzed for fallout radionuclides resulting from the Fukushima nuclear accident by the Low Background Facility (LBF) at the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, CA. Monitoring activities in air and rainwater began soon after the onset of the March 11, 2011 tsunami and are reported here through the end of 2012. Observed fallout isotopes include $^{131}$I, $^{132}$I,$^{132}$Te,$^{134}$Cs, $^{136}$Cs, and $^{137}$Cs. Isotopes were measured on environmental air filters, automobile filters, and in rainwater. An additional analysis of rainwater in search of $^{90}$Sr is also presented. Last, a series of food measurements conducted in September of 2013 are included due to extended media concerns of $^{134, 137}$Cs in fish. Similar measurements of fallout from the Chernobyl disaster at LBNL, previously unpublished publicly, are also presented here as a comparison with the Fukushima incident. All measurements presented also include natural radionuclides found in the environment to provide a basis for comparison., Comment: 11 pages

Published
2013

21. Compressibility measurements of quasi-one-dimensional quantum wires

Author

Smith, L. W., Hamilton, A. R., Thomas, K. J., Pepper, M., Farrer, I., Griffiths, J. P., Jones, G. A. C., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We report measurements of the compressibility of a one-dimensional (1D) quantum wire, defined in the upper well of a GaAs/AlGaAs double quantum well heterostructure. A wire defined simultaneously in the lower well probes the ability of the upper wire to screen the electric field from a biased surface gate. The technique is sensitive enough to resolve spin-splitting of the subbands in the presence of an in-plane magnetic field. We measure a compressibility signal due to the 0.7 structure and study its evolution with increasing temperature and magnetic field. We see no evidence of the formation of the quasibound state predicted by the Kondo model, instead our data are consistent with theories which predict that the 0.7 structure arises as a result of spontaneous spin polarization.

Published
2011
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22. Row coupling in an interacting quasi-one-dimensional quantum wire investigated using transport measurements

Author

Smith, L. W., Hew, W. K., Thomas, K. J., Pepper, M., Farrer, I., Anderson, D., Jones, G. A. C., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Strongly Correlated Electrons
Abstract

We study electron transport in quasi-one-dimensional wires at relatively weak electrostatic confinements, where the Coulomb interaction distorts the ground state, leading to the bifurcation of the electronic system into two rows. Evidence of finite coupling between the rows, resulting in bonding and antibonding states, is observed. At high dc source-drain bias, a structure is observed at 0.5(2e^2/h) due to parallel double-row transport, along with a structure at 0.25(2e^2/h), providing further evidence of coupling between the two rows., Comment: 4 pages, 3 figures

Published
2009
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23. Incipient Formation of an Electron Lattice in a Weakly-Confined Quantum Wire

Author

Hew, W. K., Thomas, K. J., Pepper, M., Farrer, I., Anderson, D., Jones, G. A. C., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Strongly Correlated Electrons
Abstract

We study the low-temperature transport properties of 1D quantum wires as the confinement strength V_conf and the carrier density n_1D are varied using a combination of split gates and a top gate in GaAs/AlGaAs heterostructures. At intermediate V_conf and n_1D, we observe a jump in conductance to 4e^2/h, suggesting a double wire. On further reducing n_1D, plateau at 2e^2/h returns. Our results show beginnings of the formation of an electron lattice in an interacting quasi-1D quantum wire. In the presence of an in-plane magnetic field, mixing of spin-aligned levels of the two wires gives rise to more complex states., Comment: 4 pages, 4 figures

Published
2009
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24. The voice characterisation checklist: psychometric properties of a brief clinical assessment of voices as social agents

Author

Edwards, Clementine J., primary, Owrid, Oliver, additional, Miller, Lucy, additional, Jafari, Hassan, additional, Emsley, Richard, additional, Rus-Calafell, Mar, additional, Craig, Thomas K. J., additional, Clancy, Moya, additional, McLeod, Hamish, additional, Fornells-Ambrojo, Miriam, additional, McDonnell, Jeffrey, additional, Montague, Alice, additional, Huckvale, Mark, additional, Bucci, Sandra, additional, Haddock, Gillian, additional, Garety, Philippa, additional, and Ward, Thomas, additional

Published
2023
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25. Spin-Incoherent Transport in Quantum Wires

Author

Hew, W. K., Thomas, K. J., Pepper, M., Farrer, I., Anderson, D., Jones, G. A. C., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

When a quantum wire is weakly confined, a conductance plateau appears at e^2/h with decreasing carrier density in zero magnetic field accompanied by a gradual suppression of the 2e^2/h plateau. Applying an in-plane magnetic field B|| does not alter the value of this quantization; however, the e^2/h plateau weakens with increasing B|| up to 9 T, and then strengthens on further increasing B||, which also restores the 2e^2/h plateau. Our results are consistent with spin-incoherent transport in a one-dimensional wire., Comment: 4 pages, 6 figures

Published
2008
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26. Colossal Positive Magnetoresistance in a Doped Nearly Magnetic Semiconductor

Author

Hu, Rongwei, Thomas, K. J., Lee, Y., Vogt, T., Choi, E. S., Mitrovic, V. F., Hermann, R. P., Grandjean, F., Canfield, P. C., Kim, J. W., Goldman, A. I., and Petrovic, C.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Materials Science
Abstract

We report on a positive colossal magnetoresistance (MR) induced by metallization of FeSb$_{2}$, a nearly magnetic or "Kondo" semiconductor with 3d ions. We discuss contribution of orbital MR and quantum interference to enhanced magnetic field response of electrical resistivity., Comment: 5 pages, 5 figures

Published
2008
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27. Orbital Domain Dynamics in a Doped Manganite

Author

Turner, J. J., Thomas, K. J., Hill, J. P., Pfeifer, M., Chesnel, K., Tomioka, Y., Tokura, Y., and Kevan, S. D.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The coupling of multiple degrees of freedom - charge, spin, and lattice - in manganites has mostly been considered at the microscopic level. However, on larger length scales, these correlations may be affected by strain and disorder, which can lead to short range order in these phases and affect the coupling between them. To better understand these effects, we explore the dynamics of orbitally ordered domains in a half-doped manganite near the orbital ordering phase transition. Our results suggest that the domains are largely static, and exhibit only slow fluctuations near domain boundaries., Comment: 10 pages, 4 figures

Published
2007

28. Direct observation of oxygen superstructures in manganites

Author

Grenier, S., Thomas, K. J., Hill, J. P., Staub, U., Bodenthin, Y., García-Fernández, M., Scagnoli, V., Kiryukhin, V., Cheong, S-W., Kim, B. G., and Tonnerre, J. M.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We report the observation of superstructures associated with the oxygen 2p-states in two prototypical manganites using x-ray diffraction at the oxygen K-edge. We determine the nature of the orderings and discuss our picture with respect to novel theoretical models. In the stripe order system Bi0.31 Ca0.69 MnO3, hole-doped O states are found to be orbitally ordered, at the same propagation vector as the Mn orbital ordering, but no evidence is found to support a picture of oxygen charge stripes at this periodicity. In La 7/8 Sr 1/8 MnO3, we observe a 2p charge ordering described by alternating hole-poor and hole-rich MnO planes that is consistent with recent predictions., Comment: 5 pages

Published
2007
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29. Hyperfine effects in quantum wires

Author

Sawkey, D. L., Thomas, K. J., Pepper, M., Tripathi, V., Khmelnitskii, D. E., Graham, A. C., Farrer, I., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Strongly Correlated Electrons
Abstract

This paper has been removed., Comment: Withdrawn

Published
2005

30. Temperature dependent d-d excitations in manganites probed by resonant inelastic x-ray scattering

Author

Grenier, S., Hill, J. P., Kiryukhin, V., Ku, W., Kim, Y. -J., Thomas, K. J., Cheong, S-W., Tokura, Y., Tomioka, Y., Casa, D., and Gog, T.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We report the observation of temperature dependent electronic excitations in various manganites utilizing resonant inelastic x-ray scattering (RIXS) at the Mn K-edge. Excitations were observed between 1.5 and 16 eV with temperature dependence found as high as 10 eV. The change in spectral weight between 1.5 and 5 eV was found to be related to the magnetic order and independent of the conductivity. On the basis of LDA+U and Wannier function calculations, this dependence is associated with intersite d-d excitations. Finally, the connection between the RIXS cross-section and the loss function is addressed., Comment: 5 pages, 5 figures

Published
2004
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31. Fano factor reduction on the 0.7 structure in a ballistic one-dimensional wire

Author

Roche, P., Segala, J., Glattli, D. C., Nicholls, J. T., Pepper, M., Graham, A. C., Thomas, K. J., Simmons, M. Y., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We have measured the non-equilibrium current noise in a ballisticone-dimensional wire which exhibits an additional conductanceplateau at $0.7\times2e^2/h$. The Fano factor shows a clearreduction on the 0.7 structure, and eventually vanishes uponapplying a strong parallel magnetic field. These results provideexperimental evidence that the 0.7 structure is associated withtwo conduction channels which have different transmissionprobabilities.

Published
2004
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32. Soft x-ray resonant diffraction study of magnetic and orbital correlations in a manganite near half-doping

Author

Thomas, K. J., Hill, J. P., Kim, Y-J., Grenier, S., Abbamonte, P., Venema, L., Rusydi, A., Tomioka, Y., Tokura, Y., McMorrow, D. F., and van Veenendaal, M.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We have utilized the resonant x-ray diffraction technique at the Mn L-edge in order to directly compare magnetic and orbital correlations in the Mn sub-lattice of Pr0.6Ca0.4MnO3. The resonant line shape is measured below T_OO ~ 240 K at the orbital ordering wave vector (0,1/2,0), and below T_N ~ 175 K at the antiferromagnetic wave vector (1/2,0,0). Comparing the width of the super-lattice peaks at the two wavevectors, we find that the correlation length of the magnetism exceeds that of the orbital order by nearly a factor of two. Furthermore, we observe a large (~ 3 eV) shift in spectral weight between the magnetic and orbital line shapes, which cannot be explained within the classic Goodenough picture of a charge-ordered ground state. To explain the large shift, we calculate the resonant line shapes for orbital and magnetic diffraction based on a relaxed charge-ordered model., Comment: 5 pages, 4 figures

Published
2003
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33. Interaction Effects at Crossings of Spin-Polarised One-Dimensional Subbands

Author

Graham, A. C., Thomas, K. J., Pepper, M., Cooper, N. R., Simmons, M. Y., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We report conductance measurements of ballistic one-dimensional (1D) wires defined in GaAs/AlGaAs heterostructures in an in-plane magnetic field, B. When the Zeeman energy is equal to the 1D subband energy spacing, the spin-split subband N(up-spin) intersects (N+1)(down-spin), where N is the index of the spin-degenerate 1D subband. At the crossing of N=1(up-spin) and N=2(down-spin) subbands, there is a spontaneous splitting giving rise to an additional conductance structure evolving from the 1.5(2e^2/h) plateau. With further increase in B, the structure develops into a plateau and lowers to 2e^2/h. With increasing temperature and magnetic field the structure shows characteristics of the 0.7 structure. Our results suggest that at low densities a spontaneous spin splitting occurs whenever two 1D subbands of opposite spins cross., Comment: 4 pages, 4 figures, to be published in Physical Review Letters

Published
2003

34. Resonant x-ray diffraction study of the magnetoresistant perovskite Pr0.6Ca0.4MnO3

Author

Grenier, S., Hill, J. P., Gibbs, Doon, Thomas, K. J., Zimmermann, M. v., Nelson, C. S., Kiryukhin, V., Tokura, Y., Casa, D., Gog, T., and Venkataraman, C.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We report a x-ray resonant diffraction study of the perovskite Pr0.6Ca0.4MnO3. At the Mn K-edge, this technique is sensitive to details of the electronic structure of the Mn atoms. We discuss the resonant x-ray spectra measured above and below the charge and orbital ordering phase transition temperature (TCOO = 232 K), and present a detailed analysis of the energy and polarization dependence of the resonant scattering. The analysis confirms that the structural transition is a transition to an orbitally ordered phase in which inequivalent Mn atoms are ordered in a CE-type pattern. The Mn atoms differ mostly by their 3d orbital occupation. We find that the charge disproportionation is incomplete, 3d^{3.5-\delta} and 3d^{3.5+\delta} with \delta\ll0.5 . A revised CE-type model is considered in which there are two Mn sublattices, each with partial e_{g} occupancy. One sublattice consists of Mn atoms with the 3x^{2}-r^{2} or 3y^{2}-r^{2} orbitals partially occupied, the other sublattice with the x^{2}-y^{2} orbital partially occupied., Comment: 15 pages, 15 figures

Published
2003
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35. Effects of accidental microconstriction on the quantized conductance in long wires

Author

Starikov, A. A., Yakimenko, I. I., Berggren, K. -F., Graham, A. C., Thomas, K. J., Pepper, M., and Simmons, M. Y.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We have investigated the conductance of long quantum wires formed in GaAs/AlGaAs heterostructures. Using realistic fluctuation potentials from donor layers we have simulated numerically the conductance of four different kinds of wires. While ideal wires show perfect quantization, potential fluctuations from random donors may give rise to strong conductance oscillations and degradation of the quantization plateaux. Statistically there is always the possibility of having large fluctuations in a sample that may effectively act as a microconstriction. We therefore introduce microconstrictions in the wires by occasional clustering of donors. These microconstrictions are found to restore the quantized plateaux. A similar effect is found for accidental lithographic inaccuracies., Comment: 4 pages, 2 figures, paper for NANO2002 symposium, will appear in SPIE proceedings

Published
2002
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36. Enhancement of long-range magnetic order by magnetic field in superconducting La2CuO(4+y)

Author

Khaykovich, B., Lee, Y. S., Erwin, R., Lee, S. -H., Wakimoto, S., Thomas, K. J., Kastner, M. A., and Birgeneau, R. J.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Strongly Correlated Electrons
Abstract

We report a detailed study, using neutron scattering, transport and magnetization measurements, of the interplay between superconducting (SC) and spin density wave (SDW) order in La2CuO(4+y). Both kinds of order set in below the same critical temperature. However, the SDW order grows with applied magnetic field, whereas SC order is suppressed. Most importantly, the field dependence of the SDW Bragg peak intensity has a cusp at zero field, as predicted by a recent theory of competing SDW and SC order. This leads us to conclude that there is a repulsive coupling between the two order parameters. The question of whether the two kinds of order coexist or microscopically phase separate is discussed., Comment: Version accepted for publication in Phys. Rev. B. Improved discussion in connection with the muSR results

Published
2001
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38. Magnetic properties of the S=1/2 quasi-one-dimensional antiferromagnet CaCu2O3

Author

Kiryukhin, V., Kim, Y. J., Thomas, K. J., Chow, F. C., Erwin, R. W., Huang, Q., Kastner, M. A., and Birgeneau, R. J.

Subjects
Condensed Matter
Abstract

We report single crystal growth and magnetic susceptibility and neutron diffraction studies of the S=1/2 quasi-1D antiferromagnet CaCu2O3. The structure of this material is similar to that of the prototype two-leg spin-ladder compound SrCu2O3. However, the Cu-O-Cu bond angle in the ladder rungs in CaCu2O3 is equal to 123 deg, and therefore the magnetic interaction along the rungs is expected to be much weaker in this material. At high temperatures, the magnetic susceptibility of CaCu2O3 can be decomposed into a contribution from 1D antiferromagnetic chains of finite-size chain segments together with a weak Curie contribution. The intrachain magnetic exchange constant, determined from the magnetic susceptibility measurements, is 2000 K. CaCu2O3 undergoes a Neel transition at T_N=25 K with ordering wavevector of (0.429(5), 0.5, 0.5). The magnetic structure is incommensurate in the direction of the frustrated interchain interaction. Weak commensurate (0.5, 0.5, 0.5) magnetic peaks are also observed below T_N. Application of a magnetic field induces a metamagnetic transition at which the incommensurability of the magnetic structure is substantially reduced. The material possesses only short-range magnetic order above the transition field., Comment: 12 pages, 10 embedded figures

Published
2000
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39. Spin Properties of Low Density One-Dimensional Wires

Author

Thomas, K. J., Nicholls, J. T., Pepper, M., Tribe, W. R., Simmons, M. Y., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We report conductance measurements of a ballistic one-dimensional (1D) wire defined in the lower two-dimensional electron gas of a GaAs/AlGaAs double quantum well. At low temperatures there is an additional structure at $0.7(2e^2/h)$ in the conductance, which tends to $e^2/h$ as the electron density is decreased. We find evidence for complete spin polarization in a weakly disorderd 1D wire at zero magnetic field through the observation of a conductance plateau at $e^2/h$, which strengthens in an in-plane magnetic field and disappears with increasing electron density. In all cases studied, with increasing temperature structure occurs at $0.6(2e^2/h)$. We suggest that the 0.7 structure is a many-body spin state excited out of, either the spin-polarized electron gas at low densities, or the spin-degenerate electron gas at high densities., Comment: 5 pages, 4 fugures, to appear in Phys. Rev. B (Rapid) 15 May 2000 issue

Published
2000
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40. Controlled Wavefunction Mixing in a Strongly Coupled One-Dimensional Wire

Author

Thomas, K. J., Nicholls, J. T., Simmons, M. Y., Tribe, W. R., Davies, A. G., and Pepper, M.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We investigate the transport properties of two strongly coupled ballistic one-dimensional (1D) wires, defined by a split-gate structure deposited on a GaAs/AlGaAs double quantum well. Matching the widths and electron densities of the two wires brings them into resonance, forming symmetric and antisymmetric 1D subbands separated by energy gaps that are measured to be larger than their two-dimensional counterpart. Applying a magnetic field parallel to the wire axes enhances wavefunction mixing at low fields, whereas at high fields the wires become completely decoupled., Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. B

Published
1999
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42. Interaction Effects in a One-Dimensional Constriction

Author

Thomas, K. J., Nicholls, J. T., Appleyard, N. J., Pepper, M., Simmons, M. Y., Mace, D. R., Tribe, W. R., and Ritchie, D. A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We have investigated the transport properties of one-dimensional (1D) constrictions defined by split-gates in high quality GaAs/AlGaAs heterostructures. In addition to the usual quantized conductance plateaus, the equilibrium conductance shows a structure close to $0.7(2e^2/h)$, and in consolidating our previous work [K.~J. Thomas et al., Phys. Rev. Lett. 77, 135 (1996)] this 0.7 structure has been investigated in a wide range of samples as a function of temperature, carrier density, in-plane magnetic field $B_{\parallel}$ and source-drain voltage $V_{sd}$. We show that the 0.7 structure is not due to transmission or resonance effects, nor does it arise from the asymmetry of the heterojunction in the growth direction. All the 1D subbands show Zeeman splitting at high $B_{\parallel}$, and in the wide channel limit the $g$-factor is $\mid g \mid \approx 0.4$, close to that of bulk GaAs. As the channel is progressively narrowed we measure an exchange-enhanced $g$-factor. The measurements establish that the 0.7 structure is related to spin, and that electron-electron interactions become important for the last few conducting 1D subbands., Comment: 8 pages, 7 figures (accepted in Phys. Rev. B)

Published
1998
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43. Possible Spin Polarization in a One-Dimensional Electron Gas

Author

Thomas, K. J., Nicholls, J. T., Simmons, M. Y., Pepper, M., Mace, D. R., and Ritchie, D. A.

Subjects
Condensed Matter
Abstract

In zero magnetic field, conductance measurements of clean one-dimensional (1D) constrictions defined in GaAs/AlGaAs heterostructures show twenty-six quantized ballistic plateaux, as well as a structure close to $0.7(2e^2/h)$. In an in-plane magnetic field all the 1D subbands show Zeeman splitting and in the wide channel limit the $g$-factor is $\mid g \mid = 0.4$, close to that of bulk GaAs. For the last subband spin-splitting originates from the structure at $0.7(2e^2/h)$, indicating spin polarization at $B=0$. The measured enhancement of the $g$-factor as the subbands are depopulated suggests that the ``0.7 structure'' is induced by electron-electron interactions., Comment: Ten pages with four ps figures. Accepted for publication in Phys. Rev. Lett. (17. June 1996)

Published
1996
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48. Social psychiatry in a rapidly changing world

Author

Thomas K. J. Craig

Subjects
society, psychosis, common mental disorder, childhood, Psychiatry, RC435-571
Abstract

Many societies around the world are experiencing a period of unprecedented change in traditional social roles and customs. Globalisation has contributed to materialism and a me-first individualism that heightens awareness of income inequality that itself is one of the most robust markers of unhappiness in society. Ever increasing urbanisation has driven an erosion of large ‘joint’ family arrangements to be replaced by smaller and relatively isolated nuclear families and single parent living. Mass migration has unmasked deep seated fear and prejudice towards the outsider in society. These global changes are fertile ground for the social conditions that have long been known to be risks for mental illness – poverty, poor quality child care, social isolation and the active discrimination and exclusion of the alien, the physically disabled and mentally ill. While there is little we can do to reverse global change, there is much a social psychiatrist can do to mitigate the effect, ensuring his/her voice is added to other calls for reducing discriminatory practice, promoting evidence-based social interventions such as parenting advice and peer support and ensuring that the success of a treatment is measured not just in terms of symptomatic improvement but in whether it results in an outcome that is valued by the patient.

Published
2016
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