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1. Optically accessible long-lived electronic biexcitons at room temperature in strongly coupled H- aggregates

Author

Siddhartha Sohoni, Indranil Ghosh, Geoffrey T. Nash, Claire A. Jones, Lawson T. Lloyd, Beiye C. Li, Karen L. Ji, Zitong Wang, Wenbin Lin, and Gregory S. Engel

Subjects
Science
Abstract

Abstract Photon absorption is the first process in light harvesting. Upon absorption, the photon redistributes electrons in the materials to create a Coulombically bound electron-hole pair called an exciton. The exciton subsequently separates into free charges to conclude light harvesting. When two excitons are in each other’s proximity, they can interact and undergo a two-particle process called exciton-exciton annihilation. In this process, one electron-hole pair spontaneously recombines: its energy is lost and cannot be harnessed for applications. In this work, we demonstrate the creation of two long-lived excitons on the same chromophore site (biexcitons) at room temperature in a strongly coupled H-aggregated zinc phthalocyanine material. We show that exciton-exciton annihilation is suppressed in these H- aggregated chromophores at fluences many orders of magnitudes higher than solar light. When we chemically connect the same aggregated chromophores to allow exciton diffusion, we observe that exciton-exciton annihilation is switched on. Our findings demonstrate a chemical strategy, to toggle on and off the exciton-exciton annihilation process that limits the dynamic range of photovoltaic devices.

Published
2024
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2. Gas adsorption and framework flexibility of CALF-20 explored via experiments and simulations

Author

Rama Oktavian, Ruben Goeminne, Lawson T. Glasby, Ping Song, Racheal Huynh, Omid Taheri Qazvini, Omid Ghaffari-Nik, Nima Masoumifard, Joan L. Cordiner, Pierre Hovington, Veronique Van Speybroeck, and Peyman Z. Moghadam

Subjects
Science
Abstract

Abstract In 2021, Svante, in collaboration with BASF, reported successful scale up of CALF-20 production, a stable MOF with high capacity for post-combustion CO2 capture which exhibits remarkable stability towards water. CALF-20’s success story in the MOF commercialisation space provides new thinking about appropriate structural and adsorptive metrics important for CO2 capture. Here, we combine atomistic-level simulations with experiments to study adsorptive properties of CALF-20 and shed light on its flexible crystal structure. We compare measured and predicted CO2 and water adsorption isotherms and explain the role of water-framework interactions and hydrogen bonding networks in CALF-20’s hydrophobic behaviour. Furthermore, regular and enhanced sampling molecular dynamics simulations are performed with both density-functional theory (DFT) and machine learning potentials (MLPs) trained to DFT energies and forces. From these simulations, the effects of adsorption-induced flexibility in CALF-20 are uncovered. We envisage this work would encourage development of other MOF materials useful for CO2 capture applications in humid conditions.

Published
2024
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3. Hydrogen storage in MOFs: Machine learning for finding a needle in a haystack

Author

Lawson T. Glasby and Peyman Z. Moghadam

Subjects
Computer software, QA76.75-76.765
Abstract

In recent years, machine learning (ML) has grown exponentially within the field of structure property predictions in materials science. In this issue of Patterns, Ahmed and Siegel scrutinize several redeveloped ML techniques for systematic investigations of over 900,000 metal-organic framework (MOF) structures, taken from 19 databases, to discover new, potentially record-breaking, hydrogen-storage materials.

Published
2021
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7. Evaluation of the $^{13}$N($\alpha$,p)$^{16}$O thermonuclear reaction rate and its impact on the isotopic composition of supernova grains

Author

Meyer, A., de Séréville, N., Laird, A. M., Hammache, F., Longland, R., Lawson, T., Pignatari, M., Audouin, L., Beaumel, D., Fortier, S., Kiener, J., Lefebvre-Schuhl, A., Pellegriti, M. G., Stanoiu, M., and Tatischeff, V.

Subjects
Nuclear Experiment, Astrophysics - Solar and Stellar Astrophysics
Abstract

It has been suggested that hydrogen ingestion into the helium shell of massive stars could lead to high $^{13}$C and $^{15}$N excesses when the shock of a core-collapse supernova passes through its helium shell. This prediction questions the origin of extremely high $^{13}$C and $^{15}$N abundances observed in rare presolar SiC grains which is usually attributed to classical novae. In this context $^{13}$N($\alpha$,p)$^{16}$O the reaction plays an important role since it is in competition with $^{13}$N $\beta^+$-decay to $^{13}$C. The $^{13}$N($\alpha$,p)$^{16}$O reaction rate used in stellar evolution calculations comes from the CF88 compilation with very scarce information on the origin of this rate. The goal of this work is to provide a recommended $^{13}$N($\alpha$,p)$^{16}$O reaction rate, based on available experimental data. Unbound nuclear states in the $^{17}$F compound nucleus were studied using the spectroscopic information of the analog states in $^{17}$O nucleus that were measured at the Alto facility using the $^{13}$C($^7$Li,t)$^{17}$O alpha-transfer reaction, and spectroscopic factors were derived using a DWBA analysis. This spectroscopic information was used to calculate a recommended $^{13}$N($\alpha$,p)$^{16}$O reaction rate with meaningful uncertainty using a Monte Carlo approach. The present $^{13}$N($\alpha$,p)$^{16}$O reaction rate is found to be within a factor of two of the previous evaluation, with a typical uncertainty of a factor 2-3. The source of this uncertainty comes from the three resonances at $E_r^{c.m.} = 221$, 741 and 959 keV. This new error estimation translates to an overall uncertainty in the $^{13}$C production of a factor of 50. The main source of uncertainty on the re-evaluated $^{13}$N($\alpha$,p)$^{16}$O reaction rate currently comes from the uncertain alpha-width of relevant $^{17}$F states.

Published
2020
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11. Experimental Verification of Multipartite Entanglement in Quantum Networks

Author

McCutcheon, W., Pappa, A., Bell, B. A., McMillan, A., Chailloux, A., Lawson, T., Mafu, M., Markham, D., Diamanti, E., Kerenidis, I., Rarity, J. G., and Tame, M. S.

Subjects
Quantum Physics
Abstract

Multipartite entangled states are a fundamental resource for a wide range of quantum information processing tasks. In particular, in quantum networks it is essential for the parties involved to be able to verify if entanglement is present before they carry out a given distributed task. Here we design and experimentally demonstrate a protocol that allows any party in a network to check if a source is distributing a genuinely multipartite entangled state, even in the presence of untrusted parties. The protocol remains secure against dishonest behaviour of the source and other parties, including the use of system imperfections to their advantage. We demonstrate the verification protocol in a three- and four-party setting using polarization-entangled photons, highlighting its potential for realistic photonic quantum communication and networking applications., Comment: 8 pages, 4 figures

Published
2016
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14. Gas adsorption and framework flexibility of CALF-20 explored via experiments and simulations

Author

Oktavian, Rama, primary, Goeminne, Ruben, additional, Glasby, Lawson T., additional, Song, Ping, additional, Huynh, Racheal, additional, Qazvini, Omid Taheri, additional, Ghaffari-Nik, Omid, additional, Masoumifard, Nima, additional, Cordiner, Joan L., additional, Hovington, Pierre, additional, Van Speybroeck, Veronique, additional, and Moghadam, Peyman Z., additional

Published
2024
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16. Research considerations for prospective studies of patients with coma and disorders of consciousness

Author

Tinti, L, Lawson, T, Molteni, E, Kondziella, D, Rass, V, Sharshar, T, Bodien, Y, Giacino, J, Mayer, S, Amiri, M, Muehlschlegel, S, Venkatasubba Rao, C, Vespa, P, Menon, D, Citerio, G, Helbok, R, Mcnett, M, Agarwal, S, Aiyagari, V, Akbari, Y, Albertson, A, Alexander, S, Alexandrov, A, Alkhachroum, A, Al-Mufti, F, Appavu, B, Gebrewold, M, Ayounb, M, Badenes, R, Bader, M, Badjiata, N, Balu, R, Barlow, B, Barra, M, Beekman, R, Beghi, E, Beqiri, E, Berlin, T, Bilotta, F, Bleck, T, Boerwinkle, V, Boly, M, Bonnel, A, Brazzi, L, Brown, E, Bulic, S, Caceres, E, Caceres, A, Cafiero, T, Carroll, E, Cediel, E, Chou, S, Claassen, J, Condie, C, Conti, A, Cosmas, K, Costa, P, Creutzfeldt, C, Dangayach, N, Dauri, M, Debicki, D, Degeorgia, M, Der-Nigoghossian, C, Desai, M, Dhar, R, Diringer, M, Durr, E, Edlow, B, Ercole, A, Estraneo, A, Falcone, G, Farrokh, S, Ferguson, A, Fernandez-Espejo, D, Fink, E, Fins, J, Foreman, B, Franchi, F, Frontera, J, Ganesan, R, Gaspard, N, Ghavam, A, Gibbons, C, Gilmore, E, Glustein, C, Gosseries, O, Green, T, Greer, D, Guanci, M, Gupta, D, Hahn, C, Hakimi, R, Hammond, F, Hanley, D, Hartings, J, Hassan, A, Hemphill, C, Da Cunha, A, Hinson, H, Hirsch, K, Hocker, S, Hu, P, Hu, X, Human, T, Hwang, D, Illes, J, Jaffa, M, James, M, Janas, A, Johnson, S, Jones, M, Jox, R, Kalanuria, A, Keller, E, Kennedy, L, Kennelly, M, Keogh, M, Kim, J, Kim, K, Kirsch, H, Kirschen, M, Ko, N, Kreitzer, N, Kromm, J, Kumar, A, Kurtz, P, Laureys, S, Lejeune, N, Lewis, A, Liang, J, Ling, G, Livesay, S, Luppi, A, Macdonald, J, Maddux, C, Mahanes, D, Mainali, S, Maldonado, N, Ribeiro, R, Mascia, L, Massimini, M, Mathur, R, Mccredie, V, Mejia-Mantilla, J, Mendoza, M, Meyfroidt, G, Mijangos, J, Moberg, D, Moheet, A, Montalenti, E, Monti, M, Morrison, C, Munar, M, Murtaugh, B, Naccache, L, Nagayama, M, Nairon, E, Nakagawa, T, Naldi, A, Narenthiran, G, Natarajan, G, Nemetsky, E, Newcombe, V, Nielsen, N, Niznick, N, Noronha-Falcão, F, Nyquist, P, Olson, D, Othman, M, Owen, A, Padayachy, L, Pajoumand, M, Park, S, Pergakis, M, Perry, H, Polizzotto, L, Pouratian, N, Spivack, M, Prisco, L, Provencio, J, Puglises, F, Puybasset, L, Rao, C, Rasmussen, L, Rasulo, F, Ray, B, Ricci, Z, Richardson, R, Shinotsuka, C, Robba, C, Robertson, C, Rohaut, B, Rolston, J, Romagnoli, S, Rosanova, M, Rosenthal, E, Rowe, S, Rubin, M, Russell, M, Silva, G, Sanz, L, Sarasso, S, Sarwal, A, Schiff, N, Schnakers, C, Seder, D, Shah, V, Shapiro-Rosenbaubm, A, Shapshak, A, Sharma, K, Shutter, L, Sitt, J, Slomine, B, Smetana, K, Smielewski, P, Smith, W, Stamatakis, E, Steinberg, A, Stevens, R, Suarez, J, Sung, G, Sussman, B, Taran, S, Mazzeo, A, Thibaut, A, Thompson, D, Threlkeld, Z, Toker, D, Torbey, M, Tosto, J, Trevick, S, Tsaousi, G, Turgeon, A, Udy, A, Varelas, P, Videtta, W, Voss, H, Vox, F, Wagner, A, Wahlster, S, Wainwright, M, Whyte, J, Witherspoon, B, Yakhkind, A, Yeager, S, Young, M, Zafar, S, Zafonte, R, Zahuranec, D, Zammit, C, Zhang, B, Ziai, W, Zimmerman, L, Zink, E, Tinti, Lorenzo, Lawson, Thomas, Molteni, Erika, Kondziella, Daniel, Rass, Verena, Sharshar, Tarek, Bodien, Yelena G, Giacino, Joseph T, Mayer, Stephan A, Amiri, Moshgan, Muehlschlegel, Susanne, Venkatasubba Rao, Chethan P, Vespa, Paul M, Menon, David K, Citerio, Giuseppe, Helbok, Raimund, McNett, Molly, Agarwal, Sachin, Aiyagari, Venkatesh, Akbari, Yama, Albertson, Asher, Alexander, Sheila, Alexandrov, Anne, Alkhachroum, Ayham, Al-Mufti, Fawaz, Amiri, Moshagan, Appavu, Brian, Gebrewold, Meron Awraris, Ayounb, Marc, Badenes, Rafael, Bader, Mary Kay, Badjiata, Neeraj, Balu, Ram, Barlow, Brooke, Barra, Megan, Beekman, Rachel, Beghi, Ettore, Beqiri, Erta, Berlin, Tracey, Bilotta, Federico, Bleck, Thomas, Bodien, Yelena, Boerwinkle, Varina, Boly, Melanie, Bonnel, Alexandra, Brazzi, Luca, Brown, Emery, Bulic, Sebina, Caceres, Eder, Caceres, Adrian, Cafiero, Tullio, Carroll, Elizabeth, Cediel, Emilio G, Chou, Sherry, Claassen, Jan, Condie, Chad, Conti, Alfredo, Cosmas, Katie, Costa, Paolo, Creutzfeldt, Claire, Dangayach, Neha, Dauri, Mario, Debicki, Derek, DeGeorgia, Michael, Der-Nigoghossian, Caroline, Desai, Masoom, Dhar, Rajat, Diringer, Michael, Durr, Emily, Edlow, Brian, Ercole, Ari, Estraneo, Anna, Falcone, Guido, Farrokh, Salia, Ferguson, Adam, Fernandez-Espejo, Davinia, Fink, Ericka, Fins, Joseph, Foreman, Brandon, Franchi, Federico, Frontera, Jennifer, Ganesan, Rishi, Gaspard, Nicolas, Ghavam, Ahmeneh, Giacino, Joseph, Gibbons, Christie, Gilmore, Emily, Glustein, Chavie, Gosseries, Olivia, Green, Theresa, Greer, David, Guanci, Mary, Gupta, Deepak, Hahn, Cecil, Hakimi, Ryan, Hammond, Flora, Hanley, Daniel F, Hartings, Jed, Hassan, Ahmed, Hemphill, Claude, Da Cunha, Arthur Henrique Galvão Bruno, Hinson, Holly, Hirsch, Karen, Hocker, Sarah, Hu, Peter, Hu, Xiao, Human, Theresa, Hwang, David, Illes, Judy, Jaffa, Matthew, James, Michael L, Janas, Anna, Johnson, Susan, Jones, Morgan, Jox, Ralf J, Kalanuria, Atul, Keller, Emanuela, Kennedy, Lori, Kennelly, Megan, Keogh, Maggie, Kim, Jenn, Kim, Keri, Kirsch, Hannah, Kirschen, Matthew, Ko, Nerissa, Kreitzer, Natalie, Kromm, Julie, Kumar, Abhay, Kurtz, Pedro, Laureys, Steven, Lejeune, Nicolas, Lewis, Ariane, Liang, John, Ling, Geoffrey, Livesay, Sarah, Luppi, Andrea, MacDonald, Jennifer, Maddux, Craig, Mahanes, Dea, Mainali, Shraddha, Maldonado, Nelson, Ribeiro, Rennan Martins, Mascia, Luciana, Massimini, Marcello, Mathur, Rohan, Mayer, Stephan, McCredie, Victoria, Mejia-Mantilla, Jorge, Mendoza, Michael, Menon, David, Meyfroidt, Geert, Mijangos, Julio, Moberg, Dick, Moheet, Asma, Montalenti, Elisa, Monti, Martin, Morrison, Chris, Munar, Marina, Murtaugh, Brooke, Naccache, Lionel, Nagayama, Masao, Nairon, Emerson, Nakagawa, Thomas, Naldi, Andrea, Narenthiran, Ganesalingam, Natarajan, Girija, Nemetsky, Esther, Newcombe, Virginia, Nielsen, Niklas, Niznick, Naomi, Noronha-Falcão, Filipa, Nyquist, Paul, Olson, DaiWai, Othman, Marwan, Owen, Adrian, Padayachy, Llewellyn, Pajoumand, Mehrnaz, Park, Soojin, Pergakis, Melissa, Perry, Heidi, Polizzotto, Len, Pouratian, Nader, Spivack, Marilyn Price, Prisco, Lara, Provencio, Javier, Puglises, Francesco, Puybasset, Louis, Rao, Chethan, Rasmussen, Lindsay, Rasulo, Frank, Ray, Bappaditya, Ricci, Zaccaria, Richardson, Risa, Shinotsuka, Cassia Righy, Robba, Chiara, Robertson, Courtney, Rohaut, Benjamin, Rolston, John, Romagnoli, Stefano, Rosanova, Mario, Rosenthal, Eric, Rowe, Shaun, Rubin, Michael, Russell, Mary Beth, Silva, Gisele Sampaio, Sanz, Leandro, Sarasso, Simone, Sarwal, Aarti, Schiff, Nicolas, Schnakers, Caroline, Seder, David, Shah, Vishank Arun, Shapiro-Rosenbaubm, Amy, Shapshak, Angela, Sharma, Kartavya, Sharma, Kumar Ajay, Shutter, Lori, Sitt, Jacobo, Slomine, Beth, Smetana, Keaton, Smielewski, Peter, Smith, Wade, Stamatakis, Emmanuel, Steinberg, Alexis, Stevens, Robert, Suarez, Jose, Sung, Gene, Sussman, Bethany, Taran, Shaurya, Mazzeo, Anna Teresa, Thibaut, Aurore, Thompson, David, Threlkeld, Zachary, Toker, Daniel, Torbey, Michel, Tosto, Jenna, Trevick, Stephen, Tsaousi, Georgia, Turgeon, Alexis, Udy, Andrew, Varelas, Panos, Vespa, Paul, Videtta, Walter, Voss, Henning, Vox, Ford, Wagner, Amy, Wahlster, Sarah, Wainwright, Mark, Whyte, John, Witherspoon, Briana, Yakhkind, Aleksandra (Sasha), Yeager, Susan, Young, Michael, Zafar, Sahar, Zafonte, Ross, Zahuranec, Darin, Zammit, Chris, Zhang, Bei, Ziai, Wendy, Zimmerman, Lara, Zink, Elizabeth, Tinti, L, Lawson, T, Molteni, E, Kondziella, D, Rass, V, Sharshar, T, Bodien, Y, Giacino, J, Mayer, S, Amiri, M, Muehlschlegel, S, Venkatasubba Rao, C, Vespa, P, Menon, D, Citerio, G, Helbok, R, Mcnett, M, Agarwal, S, Aiyagari, V, Akbari, Y, Albertson, A, Alexander, S, Alexandrov, A, Alkhachroum, A, Al-Mufti, F, Appavu, B, Gebrewold, M, Ayounb, M, Badenes, R, Bader, M, Badjiata, N, Balu, R, Barlow, B, Barra, M, Beekman, R, Beghi, E, Beqiri, E, Berlin, T, Bilotta, F, Bleck, T, Boerwinkle, V, Boly, M, Bonnel, A, Brazzi, L, Brown, E, Bulic, S, Caceres, E, Caceres, A, Cafiero, T, Carroll, E, Cediel, E, Chou, S, Claassen, J, Condie, C, Conti, A, Cosmas, K, Costa, P, Creutzfeldt, C, Dangayach, N, Dauri, M, Debicki, D, Degeorgia, M, Der-Nigoghossian, C, Desai, M, Dhar, R, Diringer, M, Durr, E, Edlow, B, Ercole, A, Estraneo, A, Falcone, G, Farrokh, S, Ferguson, A, Fernandez-Espejo, D, Fink, E, Fins, J, Foreman, B, Franchi, F, Frontera, J, Ganesan, R, Gaspard, N, Ghavam, A, Gibbons, C, Gilmore, E, Glustein, C, Gosseries, O, Green, T, Greer, D, Guanci, M, Gupta, D, Hahn, C, Hakimi, R, Hammond, F, Hanley, D, Hartings, J, Hassan, A, Hemphill, C, Da Cunha, A, Hinson, H, Hirsch, K, Hocker, S, Hu, P, Hu, X, Human, T, Hwang, D, Illes, J, Jaffa, M, James, M, Janas, A, Johnson, S, Jones, M, Jox, R, Kalanuria, A, Keller, E, Kennedy, L, Kennelly, M, Keogh, M, Kim, J, Kim, K, Kirsch, H, Kirschen, M, Ko, N, Kreitzer, N, Kromm, J, Kumar, A, Kurtz, P, Laureys, S, Lejeune, N, Lewis, A, Liang, J, Ling, G, Livesay, S, Luppi, A, Macdonald, J, Maddux, C, Mahanes, D, Mainali, S, Maldonado, N, Ribeiro, R, Mascia, L, Massimini, M, Mathur, R, Mccredie, V, Mejia-Mantilla, J, Mendoza, M, Meyfroidt, G, Mijangos, J, Moberg, D, Moheet, A, Montalenti, E, Monti, M, Morrison, C, Munar, M, Murtaugh, B, Naccache, L, Nagayama, M, Nairon, E, Nakagawa, T, Naldi, A, Narenthiran, G, Natarajan, G, Nemetsky, E, Newcombe, V, Nielsen, N, Niznick, N, Noronha-Falcão, F, Nyquist, P, Olson, D, Othman, M, Owen, A, Padayachy, L, Pajoumand, M, Park, S, Pergakis, M, Perry, H, Polizzotto, L, Pouratian, N, Spivack, M, Prisco, L, Provencio, J, Puglises, F, Puybasset, L, Rao, C, Rasmussen, L, Rasulo, F, Ray, B, Ricci, Z, Richardson, R, Shinotsuka, C, Robba, C, Robertson, C, Rohaut, B, Rolston, J, Romagnoli, S, Rosanova, M, Rosenthal, E, Rowe, S, Rubin, M, Russell, M, Silva, G, Sanz, L, Sarasso, S, Sarwal, A, Schiff, N, Schnakers, C, Seder, D, Shah, V, Shapiro-Rosenbaubm, A, Shapshak, A, Sharma, K, Shutter, L, Sitt, J, Slomine, B, Smetana, K, Smielewski, P, Smith, W, Stamatakis, E, Steinberg, A, Stevens, R, Suarez, J, Sung, G, Sussman, B, Taran, S, Mazzeo, A, Thibaut, A, Thompson, D, Threlkeld, Z, Toker, D, Torbey, M, Tosto, J, Trevick, S, Tsaousi, G, Turgeon, A, Udy, A, Varelas, P, Videtta, W, Voss, H, Vox, F, Wagner, A, Wahlster, S, Wainwright, M, Whyte, J, Witherspoon, B, Yakhkind, A, Yeager, S, Young, M, Zafar, S, Zafonte, R, Zahuranec, D, Zammit, C, Zhang, B, Ziai, W, Zimmerman, L, Zink, E, Tinti, Lorenzo, Lawson, Thomas, Molteni, Erika, Kondziella, Daniel, Rass, Verena, Sharshar, Tarek, Bodien, Yelena G, Giacino, Joseph T, Mayer, Stephan A, Amiri, Moshgan, Muehlschlegel, Susanne, Venkatasubba Rao, Chethan P, Vespa, Paul M, Menon, David K, Citerio, Giuseppe, Helbok, Raimund, McNett, Molly, Agarwal, Sachin, Aiyagari, Venkatesh, Akbari, Yama, Albertson, Asher, Alexander, Sheila, Alexandrov, Anne, Alkhachroum, Ayham, Al-Mufti, Fawaz, Amiri, Moshagan, Appavu, Brian, Gebrewold, Meron Awraris, Ayounb, Marc, Badenes, Rafael, Bader, Mary Kay, Badjiata, Neeraj, Balu, Ram, Barlow, Brooke, Barra, Megan, Beekman, Rachel, Beghi, Ettore, Beqiri, Erta, Berlin, Tracey, Bilotta, Federico, Bleck, Thomas, Bodien, Yelena, Boerwinkle, Varina, Boly, Melanie, Bonnel, Alexandra, Brazzi, Luca, Brown, Emery, Bulic, Sebina, Caceres, Eder, Caceres, Adrian, Cafiero, Tullio, Carroll, Elizabeth, Cediel, Emilio G, Chou, Sherry, Claassen, Jan, Condie, Chad, Conti, Alfredo, Cosmas, Katie, Costa, Paolo, Creutzfeldt, Claire, Dangayach, Neha, Dauri, Mario, Debicki, Derek, DeGeorgia, Michael, Der-Nigoghossian, Caroline, Desai, Masoom, Dhar, Rajat, Diringer, Michael, Durr, Emily, Edlow, Brian, Ercole, Ari, Estraneo, Anna, Falcone, Guido, Farrokh, Salia, Ferguson, Adam, Fernandez-Espejo, Davinia, Fink, Ericka, Fins, Joseph, Foreman, Brandon, Franchi, Federico, Frontera, Jennifer, Ganesan, Rishi, Gaspard, Nicolas, Ghavam, Ahmeneh, Giacino, Joseph, Gibbons, Christie, Gilmore, Emily, Glustein, Chavie, Gosseries, Olivia, Green, Theresa, Greer, David, Guanci, Mary, Gupta, Deepak, Hahn, Cecil, Hakimi, Ryan, Hammond, Flora, Hanley, Daniel F, Hartings, Jed, Hassan, Ahmed, Hemphill, Claude, Da Cunha, Arthur Henrique Galvão Bruno, Hinson, Holly, Hirsch, Karen, Hocker, Sarah, Hu, Peter, Hu, Xiao, Human, Theresa, Hwang, David, Illes, Judy, Jaffa, Matthew, James, Michael L, Janas, Anna, Johnson, Susan, Jones, Morgan, Jox, Ralf J, Kalanuria, Atul, Keller, Emanuela, Kennedy, Lori, Kennelly, Megan, Keogh, Maggie, Kim, Jenn, Kim, Keri, Kirsch, Hannah, Kirschen, Matthew, Ko, Nerissa, Kreitzer, Natalie, Kromm, Julie, Kumar, Abhay, Kurtz, Pedro, Laureys, Steven, Lejeune, Nicolas, Lewis, Ariane, Liang, John, Ling, Geoffrey, Livesay, Sarah, Luppi, Andrea, MacDonald, Jennifer, Maddux, Craig, Mahanes, Dea, Mainali, Shraddha, Maldonado, Nelson, Ribeiro, Rennan Martins, Mascia, Luciana, Massimini, Marcello, Mathur, Rohan, Mayer, Stephan, McCredie, Victoria, Mejia-Mantilla, Jorge, Mendoza, Michael, Menon, David, Meyfroidt, Geert, Mijangos, Julio, Moberg, Dick, Moheet, Asma, Montalenti, Elisa, Monti, Martin, Morrison, Chris, Munar, Marina, Murtaugh, Brooke, Naccache, Lionel, Nagayama, Masao, Nairon, Emerson, Nakagawa, Thomas, Naldi, Andrea, Narenthiran, Ganesalingam, Natarajan, Girija, Nemetsky, Esther, Newcombe, Virginia, Nielsen, Niklas, Niznick, Naomi, Noronha-Falcão, Filipa, Nyquist, Paul, Olson, DaiWai, Othman, Marwan, Owen, Adrian, Padayachy, Llewellyn, Pajoumand, Mehrnaz, Park, Soojin, Pergakis, Melissa, Perry, Heidi, Polizzotto, Len, Pouratian, Nader, Spivack, Marilyn Price, Prisco, Lara, Provencio, Javier, Puglises, Francesco, Puybasset, Louis, Rao, Chethan, Rasmussen, Lindsay, Rasulo, Frank, Ray, Bappaditya, Ricci, Zaccaria, Richardson, Risa, Shinotsuka, Cassia Righy, Robba, Chiara, Robertson, Courtney, Rohaut, Benjamin, Rolston, John, Romagnoli, Stefano, Rosanova, Mario, Rosenthal, Eric, Rowe, Shaun, Rubin, Michael, Russell, Mary Beth, Silva, Gisele Sampaio, Sanz, Leandro, Sarasso, Simone, Sarwal, Aarti, Schiff, Nicolas, Schnakers, Caroline, Seder, David, Shah, Vishank Arun, Shapiro-Rosenbaubm, Amy, Shapshak, Angela, Sharma, Kartavya, Sharma, Kumar Ajay, Shutter, Lori, Sitt, Jacobo, Slomine, Beth, Smetana, Keaton, Smielewski, Peter, Smith, Wade, Stamatakis, Emmanuel, Steinberg, Alexis, Stevens, Robert, Suarez, Jose, Sung, Gene, Sussman, Bethany, Taran, Shaurya, Mazzeo, Anna Teresa, Thibaut, Aurore, Thompson, David, Threlkeld, Zachary, Toker, Daniel, Torbey, Michel, Tosto, Jenna, Trevick, Stephen, Tsaousi, Georgia, Turgeon, Alexis, Udy, Andrew, Varelas, Panos, Vespa, Paul, Videtta, Walter, Voss, Henning, Vox, Ford, Wagner, Amy, Wahlster, Sarah, Wainwright, Mark, Whyte, John, Witherspoon, Briana, Yakhkind, Aleksandra (Sasha), Yeager, Susan, Young, Michael, Zafar, Sahar, Zafonte, Ross, Zahuranec, Darin, Zammit, Chris, Zhang, Bei, Ziai, Wendy, Zimmerman, Lara, and Zink, Elizabeth

Abstract

Disorders of consciousness are neurological conditions characterized by impaired arousal and awareness of self and environment. Behavioural responses are absent or are present but fluctuate. Disorders of consciousness are commonly encountered as a consequence of both acute and chronic brain injuries, yet reliable epidemiological estimates would require inclusive, operational definitions of the concept, as well as wider knowledge dissemination among involved professionals. Whereas several manifestations have been described, including coma, vegetative state/unresponsive wakefulness syndrome and minimally conscious state, a comprehensive neurobiological definition for disorders of consciousness is still lacking. The scientific literature is primarily observational, and studies-specific aetiologies lead to disorders of consciousness. Despite advances in these disease-related forms, there remains uncertainty about whether disorders of consciousness are a disease-agnostic unitary entity with a common mechanism, prognosis or treatment response paradigm. Our knowledge of disorders of consciousness has also been hampered by heterogeneity of study designs, variables, and outcomes, leading to results that are not comparable for evidence synthesis. The different backgrounds of professionals caring for patients with disorders of consciousness and the different goals at different stages of care could partly explain this variability. The Prospective Studies working group of the Neurocritical Care Society Curing Coma Campaign was established to create a platform for observational studies and future clinical trials on disorders of consciousness and coma across the continuum of care. In this narrative review, the author panel presents limitations of prior observational clinical research and outlines practical considerations for future investigations. A narrative review format was selected to ensure that the full breadth of study design considerations could be addressed and to facilit

Published
2024

17. Topological cyclic homology via the norm

Author

Angeltveit, V., Blumberg, A., Gerhardt, T., Hill, M., Lawson, T., and Mandell, M.

Subjects
Mathematics - K-Theory and Homology, Mathematics - Algebraic Topology
Abstract

We describe a construction of the cyclotomic structure on topological Hochschild homology ($THH$) of a ring spectrum using the Hill-Hopkins-Ravenel multiplicative norm. Our analysis takes place entirely in the category of equivariant orthogonal spectra, avoiding use of the B\"okstedt coherence machinery. We are able to define versions of topological cyclic homology ($TC$) and TR-theory relative to a cyclotomic commutative ring spectrum $A$. We describe spectral sequences computing this relative theory $_ATR$ in terms of $TR$ over the sphere spectrum and vice versa. Furthermore, our construction permits a straightforward definition of the Adams operations on $TR$ and $TC$., Comment: Revised draft. Error about cyclotomic structure on relative THH for general A corrected

Published
2014

18. The Electromagnetic Calorimeter for the T2K Near Detector ND280

Author

Allan, D., Andreopoulos, C., Angelsen, C., Barker, G. J., Barr, G., Bentham, S., Bertram, I., Boyd, S., Briggs, K., Calland, R. G., Carroll, J., Cartwright, S. L., Carver, A., Chavez, C., Christodoulou, G., Coleman, J., Cooke, P., Davies, G., Densham, C., Di Lodovico, F., Dobson, J., Duboyski, T., Durkin, T., Evans, D. L., Finch, A., Fitton, M., Gannaway, F. C., Grant, A., Grant, N., Grenwood, S., Guzowski, P., Hadley, D., Haigh, M., Harrison, P. F., Hatzikoutelis, A., Haycock, T. D. J., Hyndman, A., Ilic, J., Ives, S., Kaboth, A. C., Kasey, V., Kellet, L., Khaleeq, M., Kogan, G., Kormos, L. L., Lawe, M., Lawson, T. B., Lister, C., Litchfield, R. P., Lockwood, M., Malek, M., Maryon, T., Masliah, P., Mavrokoridis, K., McCauley, N., Mercer, I., Metelko, C., Morgan, B., Morris, J., Muir, A., Murdoch, M., Nicholls, T., Noy, M., O'Keeffe, H. M., Owen, R. A., Payne, D., Pearce, G. F., Perkin, J. D., Poplawska, E., Preece, R., Qian, W., Ratoff, P., Raufer, T., Raymond, M., Reeves, M., Richards, D., Rooney, M., Sacco, R., Sadler, S., Schaack, P., Scott, M., Scully, D. I., Short, S., Siyad, M., Smith, R., Still, B., Sutcliffe, P., Taylor, I. J., Terri, R., Thompson, L. F., Thorley, A., Thorpe, M., Timis, C., Touramanis, C., Uchida, M. A., Uchida, Y., Vacheret, A., VanSchalkwyk, J. F., Veledar, O., Waldron, A. V., Ward, M. A., Ward, G. P., Wark, D., Wascko, M. O., Weber, A., West, N., Whitehead, L. H., Wilkinson, C., and Wilson, J. R.

Subjects
Physics - Instrumentation and Detectors
Abstract

The T2K experiment studies oscillations of an off-axis muon neutrino beam between the J-PARC accelerator complex and the Super-Kamiokande detector. Special emphasis is placed on measuring the mixing angle theta_13 by observing electron neutrino appearance via the sub-dominant muon neutrino to electron neutrino oscillation, and searching for CP violation in the lepton sector. The experiment includes a sophisticated, off-axis, near detector, the ND280, situated 280 m downstream of the neutrino production target in order to measure the properties of the neutrino beam and to understand better neutrino interactions at the energy scale below a few GeV. The data collected with the ND280 are used to study charged- and neutral-current neutrino interaction rates and kinematics prior to oscillation, in order to reduce uncertainties in the oscillation measurements by the far detector. A key element of the near detector is the ND280 electromagnetic calorimeter (ECal), consisting of active scintillator bars sandwiched between lead sheets and read outwith multi-pixel photon counters (MPPCs). The ECal is vital to the reconstruction of neutral particles, and the identification of charged particle species. The ECal surrounds the Pi-0 detector (P0D) and the tracking region of the ND280, and is enclosed in the former UA1/NOMAD dipole magnet. This paper describes the design, construction and assembly of the ECal, as well as the materials from which it is composed. The electronic and data acquisition (DAQ) systems are discussed, and performance of the ECal modules, as deduced from measurements with particle beams, cosmic rays, the calibration system, and T2K data, is described., Comment: 45 pages, 29 PDF figures. This version is accepted for publication in JINST. It includes minor changes as recommended by the referee. In particular, a bit of further information and explanation is added to several sections

Published
2013
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19. The T2K Experiment

Author

T2K Collaboration, Abe, K., Abgrall, N., Aihara, H., Ajima, Y., Albert, J. B., Allan, D., Amaudruz, P. -A., Andreopoulos, C., Andrieu, B., Anerella, M. D., Angelsen, C., Aoki, S., Araoka, O., Argyriades, J., Ariga, A., Ariga, T., Assylbekov, S., de André, J. P. A. M., Autiero, D., Badertscher, A., Ballester, O., Barbi, M., Barker, G. J., Baron, P., Barr, G., Bartoszek, L., Batkiewicz, M., Bay, F., Bentham, S., Berardi, V., Berger, B. E., Berns, H., Bertram, I., Besnier, M., Beucher, J., Beznosko, D., Bhadra, S., Birney, P., Bishop, D., Blackmore, E., Blaszczyk, F. d. M., Blocki, J., Blondel, A., Bodek, A., Bojechko, C., Bouchez, J., Boussuge, T., Boyd, S. B., Boyer, M., Braam, N., Bradford, R., Bravar, A., Briggs, K., Brinson, J. D., Bronner, C., Brook-Roberge, D. G., Bryant, M., Buchanan, N., Budd, H., Cadabeschi, M., Calland, R. G., Calvet, D., Rodríguez, J. Caravaca, Carroll, J., Cartwright, S. L., Carver, A., Castillo, R., Catanesi, M. G., Cavata, C., Cazes, A., Cervera, A., Charrier, J. P., Chavez, C., Choi, S., Chollet, S., Christodoulou, G., Colas, P., Coleman, J., Coleman, W., Collazuol, G., Connolly, K., Cooke, P., Curioni, A., Dabrowska, A., Danko, I., Das, R., Davies, G. S., Davis, S., Day, M., De La Broise, X., de Perio, P., De Rosa, G., Dealtry, T., Debraine, A., Delagnes, E., Delbart, A., Densham, C., Di Lodovico, F., Di Luise, S., Tran, P. Dinh, Dobson, J., Doornbos, J., Dore, U., Drapier, O., Druillole, F., Dufour, F., Dumarchez, J., Durkin, T., Dytman, S., Dziewiecki, M., Dziomba, M., Ellison, B., Emery, S., Ereditato, A., Escallier, J. E., Escudero, L., Esposito, L. S., Faszer, W., Fechner, M., Ferrero, A., Finch, A., Fisher, C., Fitton, M., Flight, R., Forbush, D., Frank, E., Fransham, K., Fujii, Y., Fukuda, Y., Gallop, M., Galymov, V., Ganetis, G. L., Gannaway, F. C., Gaudin, A., Gaweda, J., Gendotti, A., George, M., Giffin, S., Giganti, C., Gilje, K., Giomataris, I., Giraud, J., Ghosh, A. K., Golan, T., Goldhaber, M., Gomez-Cadenas, J. J., Gomi, S., Gonin, M., Goyette, M., Grant, A., Grant, N., Grañena, F., Greenwood, S., Gumplinger, P., Guzowski, P., Haigh, M. D., Hamano, K., Hansen, C., Hara, T., Harrison, P. F., Hartfiel, B., Hartz, M., Haruyama, T., Hasanen, R., Hasegawa, T., Hastings, N. C., Hastings, S., Hatzikoutelis, A., Hayashi, K., Hayato, Y., Haycock, T. D. J., Hearty, C., Helmer, R. L., Henderson, R., Herlant, S., Higashi, N., Hignight, J., Hiraide, K., Hirose, E., Holeczek, J., Honkanen, N., Horikawa, S., Hyndman, A., Ichikawa, A. K., Ieki, K., Ieva, M., Iida, M., Ikeda, M., Ilic, J., Imber, J., Ishida, T., Ishihara, C., Ishii, T., Ives, S. J., Iwasaki, M., Iyogi, K., Izmaylov, A., Jamieson, B., Johnson, R. A., Joo, K. K., Jover-Manas, G., Jung, C. K., Kaji, H., Kajita, T., Kakuno, H., Kameda, J., Kaneyuki, K., Karlen, D., Kasami, K., Kasey, V., Kato, I., Kawamuko, H., Kearns, E., Kellet, L., Khabibullin, M., Khaleeq, M., Khan, N., Khotjantsev, A., Kielczewska, D., Kikawa, T., Kim, J. Y., Kim, S. -B., Kimura, N., Kirby, B., Kisiel, J., Kitching, P., Kobayashi, T., Kogan, G., Koike, S., Komorowski, T., Konaka, A., Kormos, L. L., Korzenev, A., Koseki, K., Koshio, Y., Kouzuma, Y., Kowalik, K., Kravtsov, V., Kreslo, I., Kropp, W., Kubo, H., Kubota, J., Kudenko, Y., Kulkarni, N., Kurchaninov, L., Kurimoto, Y., Kurjata, R., Kurosawa, Y., Kutter, T., Lagoda, J., Laihem, K., Langstaff, R., Laveder, M., Lawson, T. B., Le, P. T., Coguie, A. Le, Ross, M. Le, Lee, K. P., Lenckowski, M., Licciardi, C., Lim, I. T., Lindner, T., Litchfield, R. P., Longhin, A., Lopez, G. D., Lu, P., Ludovici, L., Lux, T., Macaire, M., Magaletti, L., Mahn, K., Makida, Y., Malafis, C. J., Malek, M., Manly, S., Marchionni, A., Mark, C., Marino, A. D., Marone, A. J., Marteau, J., Martin, J. F., Maruyama, T., Maryon, T., Marzec, J., Masliah, P., Mathie, E. L., Matsumura, C., Matsuoka, K., Matveev, V., Mavrokoridis, K., Mazzucato, E., McCauley, N., McFarland, K. S., McGrew, C., McLachlan, T., Mercer, I., Messina, M., Metcalf, W., Metelko, C., Mezzetto, M., Mijakowski, P., Miller, C. A., Minamino, A., Mineev, O., Mine, S., Minvielle, R. E., Mituka, G., Miura, M., Mizouchi, K., Mols, J. -P., Monfregola, L., Monmarthe, E., Moreau, F., Morgan, B., Moriyama, S., Morris, D., Muir, A., Murakami, A., Muratore, J. F., Murdoch, M., Murphy, S., Myslik, J., Nagashima, G., Nakadaira, T., Nakahata, M., Nakamoto, T., Nakamura, K., Nakayama, S., Nakaya, T., Naples, D., Nelson, B., Nicholls, T. C., Nishikawa, K., Nishino, H., Nitta, K., Nizery, F., Nowak, J. A., Noy, M., Obayashi, Y., Ogitsu, T., Ohhata, H., Okamura, T., Okumura, K., Okusawa, T., Ohlmann, C., Olchanski, K., Openshaw, R., Oser, S. M., Otani, M., Owen, R. A., Oyama, Y., Ozaki, T., Pac, M. Y., Palladino, V., Paolone, V., Paul, P., Payne, D., Pearce, G. F., Pearson, C., Perkin, J. D., Pfleger, M., Pierre, F., Pierrepont, D., Plonski, P., Poffenberger, P., Poplawska, E., Popov, B., Posiadala, M., Poutissou, J. -M., Poutissou, R., Preece, R., Przewlocki, P., Qian, W., Raaf, J. L., Radicioni, E., Ramos, K., Ratoff, P., Raufer, T. M., Ravonel, M., Raymond, M., Retiere, F., Richards, D., Ritou, J. -L., Robert, A., Rodrigues, P. A., Rondio, E., Roney, M., Rooney, M., Ross, D., Rossi, B., Roth, S., Rubbia, A., Ruterbories, D., Sacco, R., Sadler, S., Sakashita, K., Sanchez, F., Sarrat, A., Sasaki, K., Schaack, P., Schmidt, J., Scholberg, K., Schwehr, J., Scott, M., Scully, D. I., Seiya, Y., Sekiguchi, T., Sekiya, H., Sheffer, G., Shibata, M., Shimizu, Y., Shiozawa, M., Short, S., Siyad, M., Smith, D., Smith, R. J., Smy, M., Sobczyk, J., Sobel, H., Sooriyakumaran, S., Sorel, M., Spitz, J., Stahl, A., Stamoulis, P., Star, O., Statter, J., Stawnyczy, L., Steinmann, J., Steffens, J., Still, B., Stodulski, M., Stone, J., Strabel, C., Strauss, T., Sulej, R., Sutcliffe, P., Suzuki, A., Suzuki, K., Suzuki, S., Suzuki, S. Y., Suzuki, Y., Swierblewski, J., Szeglowski, T., Szeptycka, M., Tacik, R., Tada, M., Tadepalli, A. S., Taguchi, M., Takahashi, S., Takeda, A., Takenaga, Y., Takeuchi, Y., Tanaka, H. A., Tanaka, K., Tanaka, M., Tanaka, M. M., Tanimoto, N., Tashiro, K., Taylor, I. J., Terashima, A., Terhorst, D., Terri, R., Thompson, L. F., Thorley, A., Thorpe, M., Toki, W., Tomaru, T., Totsuka, Y., Touramanis, C., Tsukamoto, T., Tvaskis, V., Tzanov, M., Uchida, Y., Ueno, K., Usseglio, M., Vacheret, A., Vagins, M., Van Schalkwyk, J. F., Vanel, J. -C., Vasseur, G., Veledar, O., Vincent, P., Wachala, T., Waldron, A. V., Walter, C. W., Wanderer, P. J., Ward, M. A., Ward, G. P., Wark, D., Warner, D., Wascko, M. O., Weber, A., Wendell, R., Wendland, J., West, N., Whitehead, L. H., Wikström, G., Wilkes, R. J., Wilking, M. J., Williamson, Z., Wilson, J. R., Wilson, R. J., Wong, K., Wongjirad, T., Yamada, S., Yamada, Y., Yamamoto, A., Yamamoto, K., Yamanoi, Y., Yamaoka, H., Yanagisawa, C., Yano, T., Yen, S., Yershov, N., Yokoyama, M., Zalewska, A., Zalipska, J., Zaremba, K., Ziembicki, M., Zimmerman, E. D., Zito, M., and Zmuda, J.

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

The T2K experiment is a long-baseline neutrino oscillation experiment. Its main goal is to measure the last unknown lepton sector mixing angle {\theta}_{13} by observing {\nu}_e appearance in a {\nu}_{\mu} beam. It also aims to make a precision measurement of the known oscillation parameters, {\Delta}m^{2}_{23} and sin^{2} 2{\theta}_{23}, via {\nu}_{\mu} disappearance studies. Other goals of the experiment include various neutrino cross section measurements and sterile neutrino searches. The experiment uses an intense proton beam generated by the J-PARC accelerator in Tokai, Japan, and is composed of a neutrino beamline, a near detector complex (ND280), and a far detector (Super-Kamiokande) located 295 km away from J-PARC. This paper provides a comprehensive review of the instrumentation aspect of the T2K experiment and a summary of the vital information for each subsystem., Comment: 33 pages, 32 figures, Submitted and accepted by NIM A. Editor: Prof. Chang Kee Jung, Department of Physics and Astronomy, SUNY Stony Brook, chang.jung@sunysb.edu, 631-632-8108 Submit Edited to remove line numbers

Published
2011
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20. The case for a directional dark matter detector and the status of current experimental efforts

Author

Ahlen, S., Afshordi, N., Battat, J. B. R., Billard, J., Bozorgnia, N., Burgos, S., Caldwell, T., Carmona, J. M., Cebrian, S., Colas, P., Dafni, T., Daw, E., Dujmic, D., Dushkin, A., Fedus, W., Ferrer, E., Finkbeiner, D., Fisher, P. H., Forbes, J., Fusayasu, T., Galan, J., Gamble, T., Ghag, C., Giomataris, I., Gold, M., Gomez, H., Gomez, M. E., Gondolo, P., Green, A., Grignon, C., Guillaudin, O., Hagemann, C., Hattori, K., Henderson, S., Higashi, N., Ida, C., Iguaz, F. J., Inglis, A., Irastorza, I. G., Iwaki, S., Kaboth, A., Kabuki, S., Kadyk, J., Kallivayalil, N., Kubo, H., Kurosawa, S., Kudryavtsev, V. A., Lamy, T., Lanza, R., Lawson, T. B., Lee, A., Lee, E. R., Lin, T., Loomba, D., Lopez, J., Luzon, G., Manobu, T., Martoff, J., Mayet, F., Mccluskey, B., Miller, E., Miuchi, K., Monroe, J., Morgan, B., Muna, D., Murphy, A. St. J., Naka, T., Nakamura, K., Nakamura, M., Nakano, T., Nicklin, G. G., Nishimura, H., Niwa, K., Paling, S. M., Parker, J., Petkov, A., Pipe, M., Pushkin, K., Robinson, M., Rodriguez, A., Rodriguez-Quintero, J., Sahin, T., Sanderson, R., Sanghi, N., Santos, D., Sato, O., Sawano, T., Sciolla, G., Sekiya, H., Slatyer, T. R., Snowden-Ifft, D. P., Spooner, N. J. C., Sugiyama, A., Takada, A., Takahashi, M., Takeda, A., Tanimori, T., Taniue, K., Tomas, A., Tomita, H., Tsuchiya, K., Turk, J., Tziaferi, E., Ueno, K., Vahsen, S., Vanderspek, R., Vergados, J., Villar, J. A., Wellenstein, H., Wolfe, I., Yamamoto, R. K., and Yegoryan, H.

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the case for a dark matter detector with directional sensitivity. This document was developed at the 2009 CYGNUS workshop on directional dark matter detection, and contains contributions from theorists and experimental groups in the field. We describe the need for a dark matter detector with directional sensitivity; each directional dark matter experiment presents their project's status; and we close with a feasibility study for scaling up to a one ton directional detector, which would cost around $150M., Comment: 48 pages, 37 figures, whitepaper on direct dark matter detection with directional sensitivity

Published
2009
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21. Common Data Elements for Disorders of Consciousness: Recommendations from the Working Group on Hospital Course, Confounders, and Medications

Author

Barra, M, Zink, E, Bleck, T, Caceres, E, Farrokh, S, Foreman, B, Cediel, E, Hemphill, J, Nagayama, M, Olson, D, Suarez, J, Aiyagari, V, Akbari, Y, Al-Mufti, F, Alexander, S, Alexandrov, A, Alkhachroum, A, Amiri, M, Appavu, B, Gebre, M, Bader, M, Badjiata, N, Balu, R, Beekman, R, Beghi, E, Bell, K, Beqiri, E, Berlin, T, Bodien, Y, Boerwinkle, V, Boly, M, Bonnel, A, Brown, E, Carroll, E, Chou, S, Citerio, G, Classen, J, Condie, C, Cosmas, K, Creutzfeldt, C, Dangayach, N, Degeorgia, M, Der-Nigoghoss, C, Desai, M, Diringer, M, Dullaway, J, Edlow, B, Ercole, A, Estraneo, A, Falcone, G, Padayachy, L, Park, S, Pergakis, M, Polizzotto, L, Pouratian, N, Spivack, M, Prisco, L, Provencio, J, Puybasset, L, Rasmussen, L, Rass, V, Richardson, R, Shinots, C, Robba, C, Robertson, C, Rohaut, B, Rolston, J, Rosanova, M, Rosenthal, E, Russell, M, Silva, G, Sanz, L, Sarasso, S, Sarwal, A, Schiff, N, Schnakers, C, Seder, D, Shah, V, Shapiro-Rosen, A, Shapshak, A, Sharma, K, Sharshar, T, Shutter, L, Sitt, J, Slomine, B, Smielewski, P, Smith, W, Stamatakis, E, Steinberg, A, Ferioli, S, Fernandez-Esp, D, Fink, E, Fins, J, Frontera, J, Ganesan, R, Ghavam, A, Giacino, J, Gibbons, C, Gilmore, E, Gosseries, O, Green, T, Greer, D, Guanci, M, Hahn, C, Hakimi, R, Hanley, D, Hartings, J, Hassan, A, Hinson, H, Hirsch, K, Hocker, S, Hu, P, Hu, X, Human, T, Hwang, D, Illes, J, Jaffa, M, James, M, Janas, A, Jones, M, Keller, E, Keogh, M, Kim, J, Kim, K, Kirsch, H, Kirschen, M, Ko, N, Kondziella, D, Kreitzer, N, Stevens, R, Sussman, B, Taran, S, Thibaut, A, Threlkeld, Z, Tinti, L, Toker, D, Torbey, M, Trevick, S, Turgeon, A, Udy, A, Varelas, P, Venkatasubba, C, Vespa, P, Videtta, W, Voss, H, Vox, F, Wagner, A, Wainwright, M, Whyte, J, Witherspoon, B, Yakhind, A, Zafonte, R, Zahuranec, D, Zammit, C, Zhang, B, Ziai, W, Zimmerman, L, Kromm, J, Kumar, A, Kurtz, P, Laureys, S, Lawson, T, Lejeune, N, Lewis, A, Liang, J, Ling, G, Livesay, S, Luppi, A, Madden, L, Maddux, C, Mahanes, D, Mainali, S, Maldonado, N, Ribeiro, R, Massimini, M, Mayer, S, Mccredie, V, Mcnett, M, Mejia-Mantill, J, Menon, D, Meyfroidt, G, Mijangos, J, Moberg, D, Moheet, A, Molteni, E, Monti, M, Morrison, C, Muehlschlegel, S, Murtaugh, B, Naccache, L, Nairon, E, Natarajan, G, Newcombe, V, Nielsen, N, Noronha-Falc‹, F, Nyquist, P, Othman, M, Owen, A, Barra M. E., Zink E. K., Bleck T. P., Caceres E., Farrokh S., Foreman B., Cediel E. G., Hemphill J. C., Nagayama M., Olson D. W. M., Suarez J. I., Aiyagari V., Akbari Y., Al-Mufti F., Alexander S., Alexandrov A., Alkhachroum A., Amiri M., Appavu B., Gebre M. A., Bader M. K., Badjiata N., Balu R., Beekman R., Beghi E., Bell K., Beqiri E., Berlin T., Bodien Y., Boerwinkle V., Boly M., Bonnel A., Brown E., Carroll E., Chou S., Citerio G., Classen J., Condie C., Cosmas K., Creutzfeldt C., Dangayach N., DeGeorgia M., Der-Nigoghoss C., Desai M., Diringer M., Dullaway J., Edlow B., Ercole A., Estraneo A., Falcone G., Padayachy L., Park S., Pergakis M., Polizzotto L., Pouratian N., Spivack M. P., Prisco L., Provencio J., Puybasset L., Rasmussen L., Rass V., Richardson R., Shinots C. R., Robba C., Robertson C., Rohaut B., Rolston J., Rosanova M., Rosenthal E., Russell M. B., Silva G. S., Sanz L., Sarasso S., Sarwal A., Schiff N., Schnakers C., Seder D., Shah V. A., Shapiro-Rosen A., Shapshak A., Sharma K., Sharshar T., Shutter L., Sitt J., Slomine B., Smielewski P., Smith W., Stamatakis E., Steinberg A., Ferioli S., Fernandez-Esp D., Fink E., Fins J., Frontera J., Ganesan R., Ghavam A., Giacino J., Gibbons C., Gilmore E., Gosseries O., Green T., Greer D., Guanci M., Hahn C., Hakimi R., Hanley D. F., Hartings J., Hassan A., Hinson H., Hirsch K., Hocker S., Hu P., Hu X., Human T., Hwang D., Illes J., Jaffa M., James M. L., Janas A., Jones M., Keller E., Keogh M., Kim J., Kim K., Kirsch H., Kirschen M., Ko N., Kondziella D., Kreitzer N., Stevens R., Sussman B., Taran S., Thibaut A., Threlkeld Z., Tinti L., Toker D., Torbey M., Trevick S., Turgeon A., Udy A., Varelas P., Venkatasubba C., Vespa P., Videtta W., Voss H., Vox F., Wagner A., Wainwright M., Whyte J., Witherspoon B., Yakhind A., Zafonte R., Zahuranec D., Zammit C., Zhang B., Ziai W., Zimmerman L., Kromm J., Kumar A., Kurtz P., Laureys S., Lawson T., Lejeune N., Lewis A., Liang J., Ling G., Livesay S., Luppi A., Madden L., Maddux C., Mahanes D., Mainali S., Maldonado N., Ribeiro R. M., Massimini M., Mayer S., McCredie V., McNett M., Mejia-Mantill J., Menon D., Meyfroidt G., Mijangos J., Moberg D., Moheet A., Molteni E., Monti M., Morrison C., Muehlschlegel S., Murtaugh B., Naccache L., Nairon E., Natarajan G., Newcombe V., Nielsen N., Noronha-Falc‹ F., Nyquist P., Othman M., Owen A., Barra, M, Zink, E, Bleck, T, Caceres, E, Farrokh, S, Foreman, B, Cediel, E, Hemphill, J, Nagayama, M, Olson, D, Suarez, J, Aiyagari, V, Akbari, Y, Al-Mufti, F, Alexander, S, Alexandrov, A, Alkhachroum, A, Amiri, M, Appavu, B, Gebre, M, Bader, M, Badjiata, N, Balu, R, Beekman, R, Beghi, E, Bell, K, Beqiri, E, Berlin, T, Bodien, Y, Boerwinkle, V, Boly, M, Bonnel, A, Brown, E, Carroll, E, Chou, S, Citerio, G, Classen, J, Condie, C, Cosmas, K, Creutzfeldt, C, Dangayach, N, Degeorgia, M, Der-Nigoghoss, C, Desai, M, Diringer, M, Dullaway, J, Edlow, B, Ercole, A, Estraneo, A, Falcone, G, Padayachy, L, Park, S, Pergakis, M, Polizzotto, L, Pouratian, N, Spivack, M, Prisco, L, Provencio, J, Puybasset, L, Rasmussen, L, Rass, V, Richardson, R, Shinots, C, Robba, C, Robertson, C, Rohaut, B, Rolston, J, Rosanova, M, Rosenthal, E, Russell, M, Silva, G, Sanz, L, Sarasso, S, Sarwal, A, Schiff, N, Schnakers, C, Seder, D, Shah, V, Shapiro-Rosen, A, Shapshak, A, Sharma, K, Sharshar, T, Shutter, L, Sitt, J, Slomine, B, Smielewski, P, Smith, W, Stamatakis, E, Steinberg, A, Ferioli, S, Fernandez-Esp, D, Fink, E, Fins, J, Frontera, J, Ganesan, R, Ghavam, A, Giacino, J, Gibbons, C, Gilmore, E, Gosseries, O, Green, T, Greer, D, Guanci, M, Hahn, C, Hakimi, R, Hanley, D, Hartings, J, Hassan, A, Hinson, H, Hirsch, K, Hocker, S, Hu, P, Hu, X, Human, T, Hwang, D, Illes, J, Jaffa, M, James, M, Janas, A, Jones, M, Keller, E, Keogh, M, Kim, J, Kim, K, Kirsch, H, Kirschen, M, Ko, N, Kondziella, D, Kreitzer, N, Stevens, R, Sussman, B, Taran, S, Thibaut, A, Threlkeld, Z, Tinti, L, Toker, D, Torbey, M, Trevick, S, Turgeon, A, Udy, A, Varelas, P, Venkatasubba, C, Vespa, P, Videtta, W, Voss, H, Vox, F, Wagner, A, Wainwright, M, Whyte, J, Witherspoon, B, Yakhind, A, Zafonte, R, Zahuranec, D, Zammit, C, Zhang, B, Ziai, W, Zimmerman, L, Kromm, J, Kumar, A, Kurtz, P, Laureys, S, Lawson, T, Lejeune, N, Lewis, A, Liang, J, Ling, G, Livesay, S, Luppi, A, Madden, L, Maddux, C, Mahanes, D, Mainali, S, Maldonado, N, Ribeiro, R, Massimini, M, Mayer, S, Mccredie, V, Mcnett, M, Mejia-Mantill, J, Menon, D, Meyfroidt, G, Mijangos, J, Moberg, D, Moheet, A, Molteni, E, Monti, M, Morrison, C, Muehlschlegel, S, Murtaugh, B, Naccache, L, Nairon, E, Natarajan, G, Newcombe, V, Nielsen, N, Noronha-Falc‹, F, Nyquist, P, Othman, M, Owen, A, Barra M. E., Zink E. K., Bleck T. P., Caceres E., Farrokh S., Foreman B., Cediel E. G., Hemphill J. C., Nagayama M., Olson D. W. M., Suarez J. I., Aiyagari V., Akbari Y., Al-Mufti F., Alexander S., Alexandrov A., Alkhachroum A., Amiri M., Appavu B., Gebre M. A., Bader M. K., Badjiata N., Balu R., Beekman R., Beghi E., Bell K., Beqiri E., Berlin T., Bodien Y., Boerwinkle V., Boly M., Bonnel A., Brown E., Carroll E., Chou S., Citerio G., Classen J., Condie C., Cosmas K., Creutzfeldt C., Dangayach N., DeGeorgia M., Der-Nigoghoss C., Desai M., Diringer M., Dullaway J., Edlow B., Ercole A., Estraneo A., Falcone G., Padayachy L., Park S., Pergakis M., Polizzotto L., Pouratian N., Spivack M. P., Prisco L., Provencio J., Puybasset L., Rasmussen L., Rass V., Richardson R., Shinots C. R., Robba C., Robertson C., Rohaut B., Rolston J., Rosanova M., Rosenthal E., Russell M. B., Silva G. S., Sanz L., Sarasso S., Sarwal A., Schiff N., Schnakers C., Seder D., Shah V. A., Shapiro-Rosen A., Shapshak A., Sharma K., Sharshar T., Shutter L., Sitt J., Slomine B., Smielewski P., Smith W., Stamatakis E., Steinberg A., Ferioli S., Fernandez-Esp D., Fink E., Fins J., Frontera J., Ganesan R., Ghavam A., Giacino J., Gibbons C., Gilmore E., Gosseries O., Green T., Greer D., Guanci M., Hahn C., Hakimi R., Hanley D. F., Hartings J., Hassan A., Hinson H., Hirsch K., Hocker S., Hu P., Hu X., Human T., Hwang D., Illes J., Jaffa M., James M. L., Janas A., Jones M., Keller E., Keogh M., Kim J., Kim K., Kirsch H., Kirschen M., Ko N., Kondziella D., Kreitzer N., Stevens R., Sussman B., Taran S., Thibaut A., Threlkeld Z., Tinti L., Toker D., Torbey M., Trevick S., Turgeon A., Udy A., Varelas P., Venkatasubba C., Vespa P., Videtta W., Voss H., Vox F., Wagner A., Wainwright M., Whyte J., Witherspoon B., Yakhind A., Zafonte R., Zahuranec D., Zammit C., Zhang B., Ziai W., Zimmerman L., Kromm J., Kumar A., Kurtz P., Laureys S., Lawson T., Lejeune N., Lewis A., Liang J., Ling G., Livesay S., Luppi A., Madden L., Maddux C., Mahanes D., Mainali S., Maldonado N., Ribeiro R. M., Massimini M., Mayer S., McCredie V., McNett M., Mejia-Mantill J., Menon D., Meyfroidt G., Mijangos J., Moberg D., Moheet A., Molteni E., Monti M., Morrison C., Muehlschlegel S., Murtaugh B., Naccache L., Nairon E., Natarajan G., Newcombe V., Nielsen N., Noronha-Falc‹ F., Nyquist P., Othman M., and Owen A.

Abstract

The convergence of an interdisciplinary team of neurocritical care specialists to organize the Curing Coma Campaign is the first effort of its kind to coordinate national and international research efforts aimed at a deeper understanding of disorders of consciousness (DoC). This process of understanding includes translational research from bench to bedside, descriptions of systems of care delivery, diagnosis, treatment, rehabilitation, and ethical frameworks. The description and measurement of varying confounding factors related to hospital care was thought to be critical in furthering meaningful research in patients with DoC. Interdisciplinary hospital care is inherently varied across geographical areas as well as community and academic medical centers. Access to monitoring technologies, specialist consultation (medical, nursing, pharmacy, respiratory, and rehabilitation), staffing resources, specialty intensive and acute care units, specialty medications and specific surgical, diagnostic and interventional procedures, and imaging is variable, and the impact on patient outcome in terms of DoC is largely unknown. The heterogeneity of causes in DoC is the source of some expected variability in care and treatment of patients, which necessitated the development of a common nomenclature and set of data elements for meaningful measurement across studies. Guideline adherence in hemorrhagic stroke and severe traumatic brain injury may also be variable due to moderate or low levels of evidence for many recommendations. This article outlines the process of the development of common data elements for hospital course, confounders, and medications to streamline definitions and variables to collect for clinical studies of DoC.

Published
2023

22. Low Energy Electron and Nuclear Recoil Thresholds in the DRIFT-II Negative Ion TPC for Dark Matter Searches

Author

Burgos, S., Daw, E., Forbes, J., Ghag, C., Gold, M., Hagemann, C., Kudryavtsev, V. A., Lawson, T. B., Loomba, D., Majewski, P., Muna, D., Murphy, A. St. J., Paling, S. M., Petkov, A., Plank, S. J. S., Robinson, M., Sanghi, N., Snowden-Ifft, D. P., Spooner, N. J. C., Turk, J., and Tziaferi, E.

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

Understanding the ability to measure and discriminate particle events at the lowest possible energy is an essential requirement in developing new experiments to search for weakly interacting massive particle (WIMP) dark matter. In this paper we detail an assessment of the potential sensitivity below 10 keV in the 1 m^3 DRIFT-II directionally sensitive, low pressure, negative ion time projection chamber (NITPC), based on event-by-event track reconstruction and calorimetry in the multiwire proportional chamber (MWPC) readout. By application of a digital smoothing polynomial it is shown that the detector is sensitive to sulfur and carbon recoils down to 2.9 and 1.9 keV respectively, and 1.2 keV for electron induced events. The energy sensitivity is demonstrated through the 5.9 keV gamma spectrum of 55Fe, where the energy resolution is sufficient to identify the escape peak. The effect a lower energy sensitivity on the WIMP exclusion limit is demonstrated. In addition to recoil direction reconstruction for WIMP searches this sensitivity suggests new prospects for applications also in KK axion searches.

Published
2009
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23. First measurement of the Head-Tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches

Author

Burgos, S., Daw, E., Forbes, J., Ghag, C., Gold, M., Hagemann, C., Kudryavtsev, V. A., Lawson, T. B., Loomba, D., Majewski, P., Muna, D., Murphy, A. StJ., Nicklin, G. G., Paling, S. M., Petkov, A., Plank, S. J. S., Robinson, M., Sanghi, N., Snowden-Ifft, D. P., Spooner, N. J. C., Turk, J., and Tziaferi, E.

Subjects
Astrophysics
Abstract

We present first evidence for the so-called Head-Tail asymmetry signature of neutron-induced nuclear recoil tracks at energies down to 1.5 keV/amu using the 1m^3 DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here by Cf-252 neutrons matches well that expected from massive WIMPs. The results open a powerful new means of searching for a galactic signature from WIMPs., Comment: 4 pages, 6 figures, 1 table

Published
2008
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24. Measurement of the Range Component Directional Signature in a DRIFT-II Detector using 252Cf Neutrons

Author

Burgos, S., Daw, E., Forbes, J., Ghag, C., Gold, M., Hagemann, C., Kudryavtsev, V. A., Lawson, T. B., Loomba, D., Majewski, P., Muna, D., Murphy, A. St. J., Nicklin, G. G., Paling, S. M., Petkov, A., Plank, S. J. S., Robinson, M., Sanghi, N., Snowden-Ifft, D. P., Spooner, N. J. C., Turk, J., and Tziaferi, E.

Subjects
High Energy Physics - Experiment, Astrophysics
Abstract

The DRIFT collaboration utilizes low pressure gaseous detectors to search for WIMP dark matter with directional signatures. A 252Cf neutron source was placed on each of the principal axes of a DRIFT detector in order to test its ability to measure directional signatures from the three components of very low energy (~keV/amu) recoil ranges. A high trigger threshold and the event selection procedure ensured that only sulfur recoils were analyzed. Sulfur recoils produced in the CS2 target gas by the 252Cf source closely match those expected from massive WIMP induced sulfur recoils. For each orientation of the source a directional signal from the range components was observed, indicating that the detector is directional along all 3 axes. An analysis of these results yields an optimal orientation for DRIFT detectors when searching for a directional signature from WIMPs. Additional energy dependent information is provided to aid in understanding this effect., Comment: 14 pages, 1 Table, 8 Figures

Published
2008
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25. Track Reconstruction and Performance of DRIFT Directional Dark Matter Detectors using Alpha Particles

Author

Burgos, S., Forbes, J., Ghag, C., Gold, M., Kudryavtsev, V. A., Lawson, T. B., Loomba, D., Majewski, P., McMillan, J. E., Muna, D., Murphy, A. StJ., Nicklin, G. G., Paling, S. M., Petkov, A., Plank, S. J. S., Robinson, M., Sanghi, N., Smith, N. J. T., Snowden-Ifft, D. P., Spooner, N. J. C., Sumner, T. J., Turk, J., and Tziaferi, T.

Subjects
Physics - Instrumentation and Detectors
Abstract

First results are presented from an analysis of data from the DRIFT-IIa and DRIFT-IIb directional dark matter detectors at Boulby Mine in which alpha particle tracks were reconstructed and used to characterise detector performance--an important step towards optimising directional technology. The drift velocity in DRIFT-IIa was [59.3 +/- 0.2 (stat) +/- 7.5 (sys)] m/s based on an analysis of naturally-occurring alpha-emitting background. The drift velocity in DRIFT-IIb was [57 +/- 1 (stat) +/- 3 (sys)] m/s determined by the analysis of alpha particle tracks from a Po-210 source. 3D range reconstruction and energy spectra were used to identify alpha particles from the decay of Rn-222, Po-218, Rn-220 and Po-216. This study found that (22 +/- 2)% of Po-218 progeny (from Rn-222 decay) are produced with no net charge in 40 Torr CS2. For Po-216 progeny (from Rn-220 decay) the uncharged fraction is (100 +0 -35)%., Comment: 27 pages, 12 figures, 5 tables. Submitted to Nuclear Instruments and Methods in Physics Research, Section A. Subj-class: Instrumentation and Detectors

Published
2007
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26. First Results from the DRIFT-IIa Dark Matter Detector

Author

Burgos, S., Forbes, J., Ghag, C., Gold, M., Kudryavtsev, V. A., Lawson, T. B., Loomba, D., Majewski, P., Muna, D., Murphy, A. StJ., Nicklin, G. G., Paling, S. M., Petkov, A., Plank, S. J. S., Robinson, M., Sanghi, N., Smith, N. J. T., Snowden-Ifft, D. P., Spooner, N. J. C., Sumner, T. J., Turk, J., and Tziaferi, E.

Subjects
High Energy Physics - Experiment
Abstract

Data from the DRIFT-IIa directional dark matter experiment are presented, collected during a near continuous 6 month running period. A detailed calibration analysis comparing data from gamma-ray, x-ray and neutron sources to a GEANT4 Monte Carlo simulations reveals an efficiency for detection of neutron induced recoils of 94+/-2(stat.)+/-5(sys.)%. Software-based cuts, designed to remove non-nuclear recoil events, are shown to reject 60Co gamma-rays with a rejection factor of better than 8x10-6 for all energies above threshold. An unexpected event population has been discovered and is shown here to be due to the alpha-decay of 222Rn daughter nuclei that have attached to the central cathode. A limit on the flux of neutrons in the Boulby Underground Laboratory is derived from analysis of unshielded and shielded data., Comment: 43 pages, 14 figures, submitted to Astroparticle Physics

Published
2007
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27. First limits on WIMP nuclear recoil signals in ZEPLIN-II: a two phase xenon detector for dark matter detection

Author

Alner, G. J., Araujo, H. M., Bewick, A., Bungau, C., Camanzi, B., Carson, M. J., Cashmore, R. J., Chagani, H., Chepel, V., Cline, D., Davidge, D., Davies, J. C., Daw, E., Dawson, J., Durkin, T., Edwards, B., Gamble, T., Gao, J., Ghag, C., Howard, A. S., Jones, W. G., Joshi, M., Korolkova, E. V., Kudryavtsev, V. A., Lawson, T., Lebedenko, V. N., Lewin, J. D., Lightfoot, P., Lindote, A., Liubarsky, I., Lopes, M. I., Luscher, R., Majewski, P., Mavrokoridis, K, McMillan, J. E., Morgan, B., Muna, D., Murphy, A. St. J., Neves, F., Nicklin, G. G., Ooi, W., Paling, S. M., da Cunha, J. Pinto, Plank, S. J. S., Preece, R. M., Quenby, J. J., Robinson, M., Sergiampietri, F., Silva, C., Solovov, V. N., Smith, N. J. T., Smith, P. F., Spooner, N. J. C., Sumner, T. J., Thorne, C., Tovey, D. R., Tziaferi, E., Walker, R. J., Wang, H., White, J., and Wolfs, F. L. H.

Subjects
Astrophysics
Abstract

Results are presented from the first underground data run of ZEPLIN-II, a 31 kg two phase xenon detector developed to observe nuclear recoils from hypothetical weakly interacting massive dark matter particles. Discrimination between nuclear recoils and background electron recoils is afforded by recording both the scintillation and ionisation signals generated within the liquid xenon, with the ratio of these signals being different for the two classes of event. This ratio is calibrated for different incident species using an AmBe neutron source and Co-60 gamma-ray sources. From our first 31 live days of running ZEPLIN-II, the total exposure following the application of fiducial and stability cuts was 225 kgxdays. A background population of radon progeny events was observed in this run, arising from radon emission in the gas purification getters, due to radon daughter ion decays on the surfaces of the walls of the chamber. An acceptance window, defined by the neutron calibration data, of 50% nuclear recoil acceptance between 5 keVee and 20 keVee, had an observed count of 29 events, with a summed expectation of 28.6+/-4.3 gamma-ray and radon progeny induced background events. These figures provide a 90% c.l. upper limit to the number of nuclear recoils of 10.4 events in this acceptance window, which converts to a WIMP-nucleon spin-independent cross-section with a minimum of 6.6x10^-7 pb following the inclusion of an energy dependent, calibrated, efficiency. A second run is currently underway in which the radon progeny will be eliminated, thereby removing the background population, with a projected sensitivity of 2x10^-7 pb for similar exposures as the first run., Comment: 38 Pages, 16 Figures, (v2: corrected table 2 description)

Published
2007
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28. The ZEPLIN-III dark matter detector: instrument design, manufacture and commissioning

Author

Akimov, D. Yu., Alner, G. J., Araujo, H. M., Bewick, A., Bungau, C., Burenkov, A. A., Carson, M. J., Chepel, V., Cline, D., Davidge, D., Davies, J. C., Daw, E., Dawson, J., Durkin, T., Edwards, B., Gamble, T., Chag, C., Hollingworth, R. J., Howard, A. S., Jones, W. G., Joshi, M., Kirkpatrick, J., Kovalenko, A., Kudryavtsev, V. A., Kuznetsov, I. S., Lawson, T., Lebedenko, V. N., Lewin, J. D., Lightfoot, P., Lindote, A., Liubarsky, I., Lopes, M. I., Luscher, R., McMillan, J. E., Morgan, B., Muna, D., Murphy, A. S., Neves, F., Nicklin, G. G., Paling, S. M., da Cunha, J. Pinto, Plank, S. J. S., Preece, R., Quenby, J. J., Robinson, M., Silva, C., Solovov, V. N., Smith, N. J. T., Smith, P. F., Spooner, N. J. C., Stekhanov, V., Sumner, T. J., Thorne, C., Tovey, D. R., Tziaferi, E., Walker, R. J., Wang, H., White, J., and Wolfs, F.

Subjects
Astrophysics
Abstract

We present details of the technical design and manufacture of the ZEPLIN-III dark matter experiment. ZEPLIN-III is a two-phase xenon detector which measures both the scintillation light and the ionisation charge generated in the liquid by interacting particles and radiation. The instrument design is driven by both the physics requirements and by the technology requirements surrounding the use of liquid xenon. These include considerations of key performance parameters, such as the efficiency of scintillation light collection, restrictions placed on the use of materials to control the inherent radioactivity levels, attainment of high vacuum levels and chemical contamination control. The successful solution has involved a number of novel design and manufacturing features which will be of specific use to future generations of direct dark matter search experiments as they struggle with similar and progressively more demanding requirements., Comment: 25 pages, 19 figures. Submitted to Astropart. Phys. Some figures down sampled to reduce size

Published
2006
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29. The ZEPLIN-III dark matter detector: performance study using an end-to-end simulation tool

Author

Araujo, H. M., Akimov, D. Yu., Alner, G. J., Bewick, A., Bungau, C., Camanzi, B., Carson, M. J., Chepel, V., Chagani, H., Davidge, D., Davies, J. C., Daw, E., Dawson, J., Durkin, T., Edwards, B., Gamble, T., Ghag, C., Hollingworth, R., Howard, A. S., Jones, W. G., Joshi, M., Kirkpatrick, J., Kovalenko, A., Kudryavtsev, V. A., Lebedenko, V. N., Lawson, T., Lewin, J. D., Lightfoot, P., Lindote, A., Liubarsky, I., Lopes, M. I., Luscher, R., Majewski, P., Mavrokoridis, K., McMillan, J., Morgan, B., Muna, D., Murphy, A. S., Neves, F., Nicklin, G., Paling, S., da Cunha, J. Pinto, Preece, R., Quenby, J. J., Robinson, M., Silva, C., Solovov, V. N., Smith, N. J. T., Smith, P. F., Spooner, N. J. C., Stekhanov, V., Sumner, T. J., Tovey, D. R., Thorne, C., Tziaferi, E., and Walker, R. J.

Subjects
Astrophysics
Abstract

We present results from a GEANT4-based Monte Carlo tool for end-to-end simulations of the ZEPLIN-III dark matter experiment. ZEPLIN-III is a two-phase detector which measures both the scintillation light and the ionisation charge generated in liquid xenon by interacting particles and radiation. The software models the instrument response to radioactive backgrounds and calibration sources, including the generation, ray-tracing and detection of the primary and secondary scintillations in liquid and gaseous xenon, and subsequent processing by data acquisition electronics. A flexible user interface allows easy modification of detector parameters at run time. Realistic datasets can be produced to help with data analysis, an example of which is the position reconstruction algorithm developed from simulated data. We present a range of simulation results confirming the original design sensitivity of a few times $10^{-8}$ pb to the WIMP-nucleon cross-section., Comment: Submitted to Astroparticle Physics

Published
2006
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30. Simulations of neutron background in a time projection chamber relevant to dark matter searches

Author

Carson, M. J., Davies, J. C., Daw, E., Hollingworth, R. J., Kirkpatrick, J. A., Kudryavtsev, V. A., Lawson, T. B., Lightfoot, P. K., McMillan, J. E., Morgan, B., Paling, S. M., Robinson, M., Spooner, N. J. C, Tovey, D. R., and Tziaferi, E.

Subjects
High Energy Physics - Experiment
Abstract

Presented here are results of simulations of neutron background performed for a time projection chamber acting as a particle dark matter detector in an underground laboratory. The investigated background includes neutrons from rock and detector components, generated via spontaneous fission and (alpha, n) reactions, as well as those due to cosmic-ray muons. Neutrons were propagated to the sensitive volume of the detector and the nuclear recoil spectra were calculated. Methods of neutron background suppression were also examined and limitations to the sensitivity of a gaseous dark matter detector are discussed. Results indicate that neutrons should not limit sensitivity to WIMP-nucleon interactions down to a level of (1 - 3) x 10^{-8} pb in a 10 kg detector., Comment: 27 pages (total, including 3 tables and 11 figures). Accepted for publication in Nuclear Instruments and Methods in Physics Research - Section A

Published
2005
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34. Neutron background in large-scale xenon detectors for dark matter searches

Author

Carson, M. J., Davies, J. C., Daw, E., Hollingworth, R. J., Kudryavtsev, V. A., Lawson, T. B., Lightfoot, P. K., McMillan, J. E., Morgan, B., Paling, S. M., Robinson, M., Spooner, N. J. C., and Tovey, D. R.

Subjects
High Energy Physics - Experiment
Abstract

Simulations of the neutron background for future large-scale particle dark matter detectors are presented. Neutrons were generated in rock and detector elements via spontaneous fission and (alpha,n) reactions, and by cosmic-ray muons. The simulation techniques and results are discussed in the context of the expected sensitivity of a generic liquid xenon dark matter detector. Methods of neutron background suppression are investigated. A sensitivity of $10^{-9}-10^{-10}$ pb to WIMP-nucleon interactions can be achieved by a tonne-scale detector., Comment: 35 pages, 13 figures, 2 tables, accepted for publication in Astroparticle Physics

Published
2004
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35. The NAIAD experiment for WIMP searches at Boulby mine and recent results

Author

Ahmed, B., Alner, G. J., Araujo, H., Barton, J. C., Bewick, A., Carson, M. J., Davidge, D., Dawson, J. V., Gamble, T., Hart, S. P., Hollingworth, R., Howard, A. S., Jones, W. G., Joshi, M. K., Kudryavtsev, V. A., Lawson, T. B., Lebedenko, V., Lehner, M. J., Lewin, J. D., Lightfoot, P. K., Liubarsky, I., Luscher, R., McMillan, J. E., Morgan, B., Nicklin, G., Paling, S. M., Preece, R. M., Quenby, J. J., Roberts, J. W., Robinson, M., Smith, N. J. T., Smith, P. F., Spooner, N. J. C., Sumner, T. J., and Tovey, D. R.

Subjects
High Energy Physics - Experiment
Abstract

The NAIAD experiment (NaI Advanced Detector) for WIMP dark matter searches at Boulby mine (UK) is described. The detector consists of an array of encapsulated and unencapsulated NaI(Tl) crystals with high light yield. Six crystals are collecting data at present. Data accumulated by four of them (10.6 kg x year exposure) have been used to set upper limits on the WIMP-nucleon spin-independent and WIMP-proton spin-dependent cross-sections. Pulse shape analysis has been applied to discriminate between nuclear recoils, as may be caused by WIMP interactions, and electron recoils due to gamma background. Various calibrations of crystals are presented., Comment: 22 pages, 9 figures, to be published in Astroparticle Physics

Published
2003
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37. Study and suppression of anomalous fast events in inorganic scintillators for dark matter searches

Author

Kudryavtsev, V. A., Spooner, N. J. C., Lightfoot, P. K., Roberts, J. W., Lehner, M. J., Gamble, T., Carson, M. J., Lawson, T. B., Luscher, R., McMillan, J. E., Morgan, B., Paling, S. M., Robinson, M., Tovey, D. R., Smith, N. J. T., Smith, P. F., Alner, G. J., Hart, S. P., Lewin, J. D., Preece, R. M., Sumner, T. J., Jones, W. G., Quenby, J. J., Ahmed, B., Bewick, A., Davidge, D., Dawson, J. V., Howard, A. S., Ivaniouchenkov, I., Joshi, M. K., Lebedenko, V., Liubarsky, I., Barton, J. C., Gerbier, G., Mallet, J., Mosca, L., and Tao, C.

Subjects
High Energy Physics - Experiment, Astrophysics
Abstract

The status of dark matter searches with inorganic scintillator detectors at Boulby mine is reviewed and the results of tests with a CsI(Tl) crystal are presented. The objectives of the latter experiment were to study anomalous fast events previously observed and to identify ways to remove this background. Clear indications were found that these events were due to surface contamination of crystals by alphas, probably from radon decay. A new array of unencapsulated NaI(Tl) crystals immersed either in liquid paraffin or pure nitrogen atmosphere is under construction at Boulby. Such an approach allows complete control of the surface of the crystals and the ability to remove any surface contamination. First data from the unencapsulated NaI(Tl) do not show the presence of anomalous fast events., Comment: 14 pages, 6 figures

Published
2001
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38. Measurements of Scintillation Efficiency and Pulse-Shape for Low Energy Recoils in Liquid Xenon

Author

Akimov, D., Bewick, A., Davidge, D., Dawson, J., Howard, A. S., Ivaniouchenkov, I., Jones, W. G., Joshi, M., Kudryavtsev, V. A., Lawson, T. B., Lebedenko, V., Lehner, M. J., Lightfoot, P. K., Liubarsky, I., Luscher, R., McMillan, J. E., Peak, C. D., Quenby, J. J., Spooner, N. J. C., Sumner, T. J., Tovey, D. R., and Ward, C. K.

Subjects
High Energy Physics - Experiment
Abstract

Results of observations of low energy nuclear and electron recoil events in liquid xenon scintillator detectors are given. The relative scintillation efficiency for nuclear recoils is 0.22 +/- 0.01 in the recoil energy range 40 keV - 70 keV. Under the assumption of a single dominant decay component to the scintillation pulse-shape the log-normal mean parameter T0 of the maximum likelihood estimator of the decay time constant for 6 keV < Eee < 30 keV nuclear recoil events is equal to 21.0 ns +/- 0.5 ns. It is observed that for electron recoils T0 rises slowly with energy, having a value ~ 30 ns at Eee ~ 15 keV. Electron and nuclear recoil pulse-shapes are found to be well fitted by single exponential functions although some evidence is found for a double exponential form for the nuclear recoil pulse-shape., Comment: 11 pages, including 5 encapsulated postscript figures

Published
2001
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40. CsI(Tl) for WIMP dark matter searches

Author

Kudryavtsev, V. A., Spooner, N. J. C., Tovey, D. R., Roberts, J. W., Lehner, M. J., McMillan, J. E., Lightfoot, P. K., Lawson, T. B., Peak, C. D., Luscher, R., and Barton, J. C.

Subjects
High Energy Physics - Experiment
Abstract

We report a study of CsI(Tl) scintillator to assess its applicability in experiments to search for dark matter particles. Measurements of the mean scintillation pulse shapes due to nuclear and electron recoils have been performed. We find that, as with NaI(Tl), pulse shape analysis can be used to discriminate between electron and nuclear recoils down to 4 keV. However, the discrimination factor is typically (10-15)% better than in NaI(Tl) above 4 keV. The quenching factor for caesium and iodine recoils was measured and found to increase from 11% to ~17% with decreasing recoil energy from 60 to 12 keV. Based on these results, the potential sensitivity of CsI(Tl) to dark matter particles in the form of neutralinos was calculated. We find an improvement over NaI(Tl) for the spin independent WIMP-nucleon interactions up to a factor of 5 assuming comparable electron background levels in the two scintillators., Comment: 16 pages, 8 figures, to be published in Nucl. Instrum. and Meth. in Phys. Res. A

Published
2000
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41. Characteristics of Alpha, Gamma and Nuclear Recoil Pulses from NaI(Tl) at 10-100 keV Relevant to Dark Matter Searches

Author

Kudryavtsev, V. A., Lehner, M. J., Peak, C. D., Lawson, T. B., Lightfoot, P. K., McMillan, J. E., Roberts, J. W., Spooner, N. J. C., Tovey, D. R., Ward, C. K., Smith, P. F., and Smith, N. J. T.

Subjects
High Energy Physics - Experiment
Abstract

Measurements of the shapes of scintillation pulses produced by nuclear recoils, alpha particles and photons in NaI(Tl) crystals at visible energies of 10-100 keV have been performed in order to investigate possible sources of background in NaI(Tl) dark matter experiments and, in particular, the possible origin of the anomalous fast time constant events observed in the UK Dark Matter Collaboration experiments at Boulby mine. Pulses initiated by X-rays (via photoelectric effect close to the surface of the crystal) were found not to differ from those produced by high-energy photons (via Compton electrons inside the crystal) within experimental errors. However, pulses induced by alpha particles (degraded from an external MeV source) were found to be ~10% faster than those of nuclear recoils, but insufficiently fast to account for the anomalous events., Comment: 9 pages, 2 figures, corrected misprints

Published
1999
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