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40 results on '"T. B. Lawson"'

1. Implementation of a programmable Josephson voltage standard in a zero boil-off dewar

Author

T. B. Lawson, T. J. Stewart, and L. A. Christian

Subjects
Physics, business.industry, 020208 electrical & electronic engineering, Josephson voltage standard, Electrical engineering, Zero (complex analysis), 02 engineering and technology, Cryocooler, Chip, 01 natural sciences, 010309 optics, 0103 physical sciences, Cooling power, 0202 electrical engineering, electronic engineering, information engineering, NIST, business, Watt balance, Voltage
Abstract

MSL has successfully operated a programmable Josephson array system based on a NIST 2 V chip. The system is required for MSL's watt balance under development and involves a custom cryoprobe in a zero boil-off dewar. The design of the cryoprobe and its performance will be described. For example, at the optimum microwave power of 18.6 GHz and with all chip subarrays biased, a 1.34 mA step width of the quantized voltage was obtained at 4.25 K. In this mode the cryocooler maintained reserve cooling power of approximately 100 mW.

Published
2016

2. Studies of neutron detection and backgrounds with the DRIFT-IIa dark matter detector

Author

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

Subjects
Physics, education.field_of_study, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Population, Monte Carlo method, Dark matter, Flux, Astronomy and Astrophysics, Nuclear physics, Recoil, Neutron source, Neutron detection, Neutron, Nuclear Experiment, education
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 60 Co gamma-rays with a rejection factor of better than 8 · 10 � 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 222 Rn daughter nuclei that have attached to the central cathode. A limit on the flux of neutrons (

Published
2007

3. First operation of bulk micromegas in low pressure negative ion drift gas mixtures for dark matter searches

Author

T. B. Lawson, P. K. Lightfoot, N. J. C. Spooner, S. Aune, and Ioannis Giomataris

Subjects
Physics, Dark matter, chemistry.chemical_element, Astronomy and Astrophysics, Context (language use), MicroMegas detector, Ion, Nuclear physics, Xenon, Volume (thermodynamics), chemistry, Gas detector, Total pressure, Atomic physics
Abstract

A bulk micromegas micropattern charge readout device has, for the first time, been operated at room temperature in low pressure carbon disulphide vapour. This is a key step opening prospects for use of micromegas readout for large volume negative ion time projection chambers (TPCs) without magnets, such as proposed for directional dark matter detectors and other rare event applications. The dependence of the gain on the amplification field, pressure and drift field has been evaluated. For the available gap size of 75 μm a maximum gain of 1300 ± 120 was achieved in 40 torr vapour with an energy resolution of 22% for 5.9 keV 55Fe X-rays. From a fit to the data, the Townsend coefficient gas parameters A and B have been derived. Operation has also been successfully achieved in xenon:carbon disulphide blends over a range of partial and total pressures. A gain of 890 ± 130 at an energy resolution of 35% has been recorded for a 1:1 blend at a total pressure of 80 torr. Possible improvements are discussed in the context of operation in directional dark matter TPCs as a replacement for multi-wire proportional counters.

Published
2007

4. The DRIFT-II dark matter detector: Design and commissioning

Author

J. J. Quenby, M. Gold, V. N. Lebedenko, T. Gamble, J. E. McMillan, S. Burgos, J. Turk, D. Loomba, N. Sanghi, Sean Paling, A. Petkov, G.G. Nicklin, A. Murphy, T. B. Lawson, M. Garcia, B. Morgan, E. J. Daw, P. K. Lightfoot, A. S. Howard, N. J. C. Spooner, S.J.S. Plank, E. Tziaferi, N. J. T. Smith, S. Hollen, M. J. Carson, A. Bewick, Daniel Tovey, R. Lüscher, J.C. Davies, T. J. Sumner, Daniel P. Snowden-Ifft, P.F. Smith, M. Robinson, V. A. Kudryavtsev, I. Liubarsky, J. Forbes, Rodney Walker, J.D. Lewin, G. J. Alner, J. Kirkpatrick, D. Muna, R. M. Preece, R. J. Hollingworth, C. Ghag, J. V. Dawson, and Henrique Araujo

Subjects
Physics, Nuclear and High Energy Physics, Optics, Physics::Instrumentation and Detectors, business.industry, Detector, Dark matter, Gas detector, Computer Science::Computational Geometry, business, Projection (set theory), Instrumentation, Directional Recoil Identification from Tracks
Abstract

DRIFT-II is a second generation multi-module gaseous dark matter detector. Each module contains two time projection chambers positioned back-to-back inside a stainless steel vacuum vessel containing carbon disulphide gas. This paper describes the DRIFT-II detector modules and the commissioning work performed to date.

Published
2005

5. Nuclear recoil limits from the ZEPLIN I liquid xenon WIMP dark matter detector

Author

S. M. Paling, D. C. R. Davidge, Gavin Davies, J.D. Lewin, T. Gamble, T. B. Lawson, J.C. Davies, A. Nicholls, G. J. Alner, G.T.J. Arnison, N. J. C. Spooner, T. J. Sumner, R. Lüscher, N. J. T. Smith, A. Bewick, M. J. Carson, S. P. Hart, A. S. Howard, G.G. Nicklin, P. K. Lightfoot, Daniel Tovey, J.W. Roberts, J. V. Dawson, G.J. Homer, B. Morgan, I. Ivaniouchenkov, Matthew J. Lehner, Henrique Araujo, J. E. McMillan, M. K. Joshi, R. J. Hollingworth, J.C. Barton, J. J. Quenby, R. M. Preece, T. Durkin, M. Robinson, C. Bungau, W. G. Jones, P.F. Smith, V. A. Kudryavtsev, V. N. Lebedenko, B. Camanzi, and I. Liubarsky

Subjects
Physics, Scintillation, Particle physics, Large Underground Xenon experiment, Physics::Instrumentation and Detectors, Dark matter, Detector, chemistry.chemical_element, Astronomy and Astrophysics, Nuclear physics, Recoil, Xenon, chemistry, WIMP, Space and Planetary Science, Weakly interacting massive particles, High Energy Physics::Experiment
Abstract

The ZEPLIN I detector is a zero field liquid xenon detector used in the direct search for Galactic WIMP dark matter and has been operated at 2800 mwe depth in the Boulby mine underground facility in the UK. Discrimination between the types of interaction within the liquid xenon volume is performed through measurement of the time constant of the scintillation light, nuclear recoils being characterized by a faster time constant than the predominant background from gamma and beta events. The detector design is outlined, with a discussion of the detection efficiencies and analysis procedure, leading to a 90% c.l. spin independent cross-section upper limit of 1.1 × 10−6 pb at 60 GeV WIMP mass.

Published
2005

6. Status of the ZEPLIN II experiment

Author

J.V. Dawson, A. Bewick, Daniel Tovey, M. Atac, J. J. Quenby, R. Luscher, A.S. Murphy, T. Ferbel, J. Toke, V. Lebedenko, J.E. McMillan, N. J. T. Smith, E. J. Daw, V. A. Kudryavtsev, I. Liubarsky, S.M. Paling, B. Morgan, J.D. Lewin, Yi Chen, T. J. Sumner, J. Davis, M. J. Carson, W. Skulski, F. Wolfs, N. J. C. Spooner, D.B. Cline, M.K. Joshi, R.M. Preece, A.S. Howard, X. Yang, U. Schroeder, T.J. Durkin, Haiyan Wang, D. Davidge, T. B. Lawson, P.F. Smith, F. Sergiampietri, M. Robinson, P. K. Lightfoot, P. Smith, T. Gamble, B. Camanzi, C. Ghag, C. Bungau, J. Gao, W. G. Jones, J.T. White, R. Walker, and G.J. Alner

Subjects
Nuclear physics, Physics, Cold dark matter, WIMP, Space and Planetary Science, Dark matter, Detector, Astronomy, Astronomy and Astrophysics, Astrophysics
Abstract

ZEPLIN II is a 30-kg two-phase xenon detector designed for direct detection of cold dark matter in the form of WIMPs. Currently in the commissioning phase, it will begin operation in the Boulby Mine, UK later this year. ZEPLIN II is capable of discriminating between nuclear recoils and background events and has a design reach up to two orders of magnitude beyond current limits. It will also serve as a step in the development program for a next-generation ton-scale detector.

Published
2005

7. Low energy alphas in the drift detector

Author

N. J. C. Spooner, T. B. Lawson, Daniel P. Snowden-Ifft, and N. Villaume

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Range (particle radiation), WIMP, Physics::Instrumentation and Detectors, Ionization, Weakly interacting massive particles, Dark matter, Detector, Dissipation, Instrumentation, Directional Recoil Identification from Tracks
Abstract

The Directional Recoil Identification From Tracks project is a US–UK endeavor to build and operate a low pressure negative ion TPC (NITPC) to search for weakly interacting massive particles (WIMPs) thought to make up the dark matter in our Galaxy. Low energy (∼10 keV) alpha events from U and Th decays within the walls and wires of the detector can enter the active volume of the detector and be confused for WIMP interactions. This paper presents data on and a model of low energy alphas in a NITPC operated at 40 Torr CS 2 with the aim of understanding and removing this potentially serious background. A comparison of the data to this model reveals good agreement with range predictions of SRIM2000 and allows us to calculate the energy dissipation per ion pair, W =19.0±0.5 eV for low energy alphas in CS 2 .

Published
2004

8. Recent results of the dark matter search with NaI(T1) detectors at boulby mine

Author

T. Gamble, J. E. McMillan, B. Ahmed, R. M. Preece, V. N. Lebedenko, G. J. Alnerb, Max Robinson, T. B. Lawson, D. C. R. Davidge, S. P. Hart, M. K. Joshi, J. C. Barton, G.G. Nicklin, A. Bewick, W. G. Jones, P.F. Smith, J. W. Roberts, J.D. Lewin, T. J. Sumner, R. Lüscher, I. Liubaxsky, Daniel Tovey, M. J. Carson, N. J. T. Smith, V. A. Kudryavtsev, J. V. Dawson, N.J.C. Spoone, A. S. Howard, B. Morgan, P. K. Lightfoot, R. J. Hollingworth, Matthew J. Lehner, S. M. Paling, and J. J. Quenby

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, WIMP, Dark matter, Scintillation counter, Detector, Atomic and Molecular Physics, and Optics, Particle detector
Abstract

The NAIAD (NaI Advanced Detector) experiment for WIMP dark matter searches at Boulby Mine (UK) is described. The detector consists of an array of encapsulated and unencapsulated NaI(T1) crystals with high light yield. Six crystals are collecting data at present. Data accumulated by four of them have been used to set new limits on the WIMP-nucleon spin-independent cross-section.

Published
2003

9. First results from the DRIFT-1 detector

Author

N. J. C. Spooner, R. Ayad, C. J. Martoff, Daniel P. Snowden-Ifft, S. M. Paling, T. B. Lawson, J. Kirkpatrick, and B. Morgan

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Physics::Instrumentation and Detectors, Dark matter, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Atomic and Molecular Physics, and Optics, Nuclear physics, WIMP, High Energy Physics::Experiment, Sensitivity (control systems), Nuclear Experiment
Abstract

DRIFT-I is the world's first WIMP dark matter detector with sensitivity to the direction of nuclear recoils. This article discusses the DRIFT-I detector, and presents some preliminary data from underground engineering runs.

Published
2003

10. The potential of liquid xenon for WIMP search: the ZEPLIN diagnostic array

Author

B. Ahmed, T. B. Lawson, T.J. Summer, J. W. Roberts, C.D. Peak, J. C. Barton, I. Ivaniouchenkov, R. M. Preece, N. J. T. Smith, N.C.J. Spooner, Daniel Tovey, D. C. R. Davidge, T. Ali, W. G. Jones, J. J. Quenby, T. Gamble, P.F. Smith, J. E. McMillan, A. Bewick, G. J. Alner, M. K. Joshi, V. A. Kudryavtsev, J. V. Dawson, A. S. Howard, V. N. Lebedenko, P. K. Lightfoot, Matthew J. Lehner, I. Liubarsky, R. Luscher, J.D. Lewin, and S.T. Hart

Subjects
Physics, Nuclear and High Energy Physics, Photomultiplier, business.industry, ZEPLIN-III, Detector, chemistry.chemical_element, Atomic and Molecular Physics, and Optics, Xenon, Optics, WIMP, chemistry, Pulse shape analysis, business
Abstract

A Liquid Xenon based WIMP detector diagnostic array is currently developed by the UKDMC with the help of international collaborators. After a brief reminder on the detection principle in Liquid Xenon, the individual detectors will be described. ZEPLIN I, a detector with a 4 kg fiducial mass with a background discrimination based on Pulse Shape Analysis, is already underground and starting operation. Two setups with improved background discrimination tools (as the ionisation is also recorded) are designed and scheduled to move underground in the second half of 2001. Both of them, ZEPLIN II and ZEPLIN III, are predicted to be sensitive to rate of 0.1–0.01 events/kg/day within 2 years of data taking. Furthermore, new ideas for lower background readout devices are studied, in order to avoid the use of PhotoMultiplier Tubes (PMTs).

Published
2001

11. NaI dark matter limits and the NAIAD array – a detector with improved sensitivity to WIMPs using unencapsulated NaI

Author

J. J. Quenby, C.D. Peak, N. J. C. Spooner, N. J. T. Smith, P. K. Lightfoot, T. J. Sumner, I. Liubarsky, Matthew J. Lehner, J. C. Barton, J.D. Lewin, T. B. Lawson, J. W. Roberts, A. Bewick, G.J. Homer, Daniel Tovey, W. G. Jones, P.F. Smith, G. J. Alner, J. E. McMillan, and V. A. Kudryavtsev

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Recoil, WIMP, Monte Carlo method, Detector, Dark matter, Sensitivity (electronics), Spin-½
Abstract

Re-analysis of published data from the UKDMC NaI Tl dark matter experiment is presented using latest spin factors and comparison is made with the sensitivity predicted for NAIAD, a 100 kg NaI detector concept based on unencapsulated . NaI Tl . We present experimental results and Monte Carlo simulations for NAIAD and show that a factor of 1.5-2 improvement in energy threshold is achievable over conventional NaI dark matter detectors with consequent ; 50% improvement in nuclear recoil discrimination at 10 keV. An overall improvement in sensitivity to spin dependent WIMP interactions of factor 50, based on 100 kg = yrs of data, is predicted relative to previous UKDMC limits. q 2000 Published by Elsevier Science B.V. All rights reserved.

Published
2000

12. Characteristics of alpha, gamma and nuclear recoil pulses from NaI(Tl) at 10–100 keV relevant to dark matter searches

Author

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

Subjects
UK Dark Matter Collaboration, Physics, Nuclear and High Energy Physics, Particle physics, Scintillation, Photon, Physics::Instrumentation and Detectors, Dark matter, FOS: Physical sciences, Alpha particle, Electron, Photoelectric effect, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Recoil
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., 9 pages, 2 figures, corrected misprints

Published
1999

13. Cocomposting of Crawfish and Agricultural Processing By-Products

Author

B. J. Cochran, M. Y. Minkara, G. A. Breitenbeck, and T. B. Lawson

Subjects
Ecology, Waste management, business.industry, Compost, Soil Science, engineering.material, Rice hulls, Volume (thermodynamics), Agriculture, Bark (sound), engineering, Environmental science, business, Bagasse, Waste Management and Disposal, Water content
Abstract

Disposal of crawfish processing residuals (hereinafter, referred to as crawfish residuals) poses a challenging problem to the rapidly expanding crawfish industry. Cocomposting is examined as a waste management alternative to landfill disposal. Four agricultural processing by-products were evaluated for use as bulking agents in composting crawfish residuals: wood chips, rice hulls, bagasse, and bark. Approximately 5 to 6.5 volumes of each bulking agents were mixed with one volume of crawfish residuals in 0.3-m3 composting reactors. Compost temperature was continuously monitored, and moisture content was maintained within a desirable range. Samples were collected twice weekly throughout the 50-d composting process. Use of bagasse as a bulking agent led to the largest reduction in volatile solids (27.6 percent), organic C (55.3 percent), particle size (64.7 percent), and compost volume (52.8 percent). Finished compost using bagasse contained the greatest concentration of N (18.4 g N/kg and 160 mg NH4-N/kg). ...

Published
1998

14. A zero boil-off dewar for use with a cryogenic current comparator

Author

M. D. Early and T. B. Lawson

Subjects
Squid, Materials science, biology, business.industry, Liquid helium, Electrical engineering, chemistry.chemical_element, Cryogenics, Cryocooler, Temperature measurement, Cryogenic current comparator, law.invention, Optics, chemistry, law, biology.animal, Microphonics, business, Helium
Abstract

We describe the initial performance of our CCC / SQUID insert with a cryocooled dewar based on a two-stage pulse tube that maintains a pool of liquid helium within a sample space. The heat-leak into the liquid helium pool was calculated at ∼ 180 mW. When the unit was actively cooling, microphonic signals were seen in the SQUID output mostly below 20 kHz, however, the RF SQUID remained stable and locked at its operating point. The cryocooler may be switched off for periods of several hours during sensitive measurements, if necessary.

Published
2012

15. The T2K Experiment

Author

J. Ilic, Ferran Grañena, Biagio Rossi, Hiroyuki Sekiya, J. Zmuda, A. Suzuki, T. Szeglowski, Soo-Bong Kim, S. Dytman, Kendall Mahn, J. Bouchez, Masashi Yokoyama, E. Delagnes, E. Poplawska, Thorsten Lux, M. Messina, Sy Suzuki, M. Murdoch, V. Kasey, M. Gonin, S. Gomi, A. V. Waldron, P. A. Rodrigues, K. Suzuki, Y. Takeuchi, L. Escudero, Kenichi Tanaka, J. Dobson, R. Langstaff, P. Vincent, Tsuyoshi Nakaya, J. Kubota, P. Paul, S. Yen, T. Yano, S. M. Oser, J. Caravaca Rodríguez, H.A. Tanaka, Shinya Yamada, K. Briggs, Minoru Otani, J. Statter, Joshua Hignight, Yoshihiro Suzuki, D. Ruterbories, Y. Seiya, M. Khaleeq, A. Le Coguie, Achim Stahl, M. A. Ward, A. S. Tadepalli, Hiroaki Aihara, P. N. Ratoff, T. Kutter, J. Schwehr, Kimihiro Okumura, J. M. Poutissou, C. Bronner, J.P. Mols, M. Boyer, Jean-Charles Vanel, A. K. Ichikawa, S. Herlant, S. Roth, R. E. Minvielle, W. Toki, C. Yanagisawa, M. Goldhaber, M. Zito, P. Cooke, D. G. Brook-Roberge, Luigi Salvatore Esposito, Kieran P. Ramos, T. C. Nicholls, O. Araoka, Henry W. Sobel, M. Fitton, T. M. Raufer, J. Lagoda, I. Kreslo, J. Escallier, P. Mijakowski, M. M. Khabibullin, J. Blocki, Andrew Marone, K. Nishikawa, D. Morris, Joseph Muratore, J. Carroll, K. Abe, R. Sacco, A. Terashima, C. McGrew, Y. Totsuka, Susumu Takahashi, Ioannis Giomataris, Gareth J. Barker, S. Murphy, C. Ohlmann, D. Richards, Y. Shimizu, W. Metcalf, C. K. Jung, J. L. Raaf, D. Kielczewska, M. Batkiewicz, A. Dabrowska, D. Allan, N. West, I. Kato, C. Andreopoulos, G. Nagashima, S. Horikawa, T. Lindner, P. Amaudruz, Y. Obayashi, C. Densham, T. Wongjirad, L. L. Kormos, D. Ross, A. Delbart, T. Ishida, T. Boussuge, M. A. George, Toru Ogitsu, Hiroyuki Kawamuko, M. J. Wilking, K. Mizouchi, S. Chollet, S. L. Cartwright, Takaaki Kajita, G. D. Lopez, Ping Lu, Dmitriy Beznosko, Julien Schmidt, F. Retiere, P. Kitching, M. Iwasaki, C. Bojechko, J. P. Coleman, K. Hamano, Kevin Connolly, J. Steinmann, Jan T. Sobczyk, I. Mercer, T. Tsukamoto, J. Kisiel, H. G. Berns, Hidetoshi Kubo, M. Taguchi, Viktor Matveev, V. Galymov, K. Laihem, A. Zalewska, J. Gaweda, Federico Sanchez, Hirokatsu Ohhata, Y. Fukuda, D. Autiero, Norio Higashi, K. Gilje, A. Gendotti, R. G. Calland, K. Mavrokoridis, F. d. M. Blaszczyk, A. Robert, M. Noy, E. Radicioni, A. Bodek, K. Nitta, Marek Stodulski, M. O. Wascko, E. Kearns, K. Zaremba, F. Nizery, D. Naples, B. A. Popov, J. Wendland, E. L. Mathie, B. Ellison, A. Izmaylov, M. Goyette, U. Dore, A. Thorley, A. Korzenev, Atsushi Takeda, T. Maryon, J. Doornbos, M. Ieva, S. W. Sadler, R. Tacik, Alexander Finch, O. Ballester, M. Le Ross, D. L. Wark, M. Siyad, C. Matsumura, D. Payne, M. Y. Pac, Michael Roney, R. Flight, S. B. Boyd, G. Jover-Manas, A. Carver, M. Miura, T. Ozaki, T. Hasegawa, S. Mine, A. Debraine, P. Wanderer, J. J. Gomez-Cadenas, Yoshinari Hayato, T. Ishii, Kate Scholberg, M. Hartz, B. Kirby, K. Hayashi, J. L. Stone, S. Manly, J. Steffens, E. Mazzucato, G. F. Pearce, Nadeem A. Khan, P. Schaack, K. Koseki, K. Kaneyuki, S. Nakayama, Y. Kouzuma, R.P. Kurjata, S. W. Bentham, J. P. Charrier, K. Kowalik, T. Okusawa, D. Warner, W. Faszer, T. Hara, A. Sarrat, S. Short, J. P. A. M. de André, N. C. Hastings, P. Plonski, A. D. Marino, S. W. K. Emery, C. J. Malafis, A. N. Khotjantsev, M. Barbi, B. Jamieson, M. M. Tanaka, N. Kimura, S. Y. Suzuki, I. Z. Danko, A. Bravar, T. Dealtry, C. Fisher, Y. Kurimoto, P. Guzowski, Y. Fujii, M. Szeptycka, R. Poutissou, K. Ieki, M. Ikeda, W. Coleman, André Rubbia, G. Sheffer, T. Durkin, J. D. Perkin, C. Licciardi, Rituparna Das, D. Karlen, D. Smith, O. Star, K. Tashiro, J. Brinson, Koh Ueno, P. Sutcliffe, Hs Budd, I. Taylor, J. Myslik, J. F. van Schalkwyk, Katsuyu Kasami, P. Masliah, M. Vagins, V. Tvaskis, R. J. Wilkes, R. Openshaw, Michael Anerella, R. Castillo, Yuichi Oyama, F. Bay, F. Di Lodovico, M. Tada, L. Bartoszek, Masato Shiozawa, A. C. Weber, N. Tanimoto, R. P. Litchfield, E. Frank, Marco Laveder, A. Ferrero, R. A. Johnson, Omar Veledar, T. Golan, J. Giraud, B. Morgan, T. Komorowski, A. Muir, Yasuo Ajima, T. McLachlan, D. A. Forbush, Akitaka Ariga, B. Andrieu, David Calvet, A. Blondel, Iain Alexander Bertram, J. Imber, S. Moriyama, Barry L. Nelson, Robert D. Preece, Kodai Matsuoka, M. Fechner, G. Wikström, S. Bhadra, S. Assylbekov, P. F. Harrison, Fred Gannaway, M. B. Smy, Shigeki Aoki, R. Terri, Koji Yamamoto, J. Marzec, N. Braam, Frédéric Dufour, J. Holeczek, S. Giffin, T. D. J. Haycock, Michal Dziewiecki, M. Shibata, N. J. Buchanan, L. Monfregola, H. Nishino, G. P. Ward, I. T. Lim, N. Grant, P. Gumplinger, A. Hyndman, P. de Perio, Yoshikazu Yamada, A. Hatzikoutelis, N. Honkanen, L. Kellet, C. A. Miller, P. Birney, G. Collazuol, Mark Scott, T. Kikawa, R. L. Helmer, A. Minamino, Carlos A. Chavez, O. Drapier, F. Moreau, R. Hasanen, E. Monmarthe, Y. Kurosawa, L. Magaletti, C. Giganti, Oleg Mineev, D. I. Scully, C. Touramanis, X. De La Broise, Antonio Ereditato, A. Cazes, J. A. Nowak, M. Malek, N. Yershov, A. Cervera, M. Ziembicki, M. Dziomba, V. Palladino, C. Ishihara, Kevin Scott McFarland, V. Paolone, P. Poffenberger, J. Dumarchez, M. Gallop, T. Strauss, T. Maruyama, J. Zalipska, Yasuhiro Makida, L. Stawnyczy, T. Nakadaira, A. Yamamoto, G.D. Barr, P. Colas, Scott Davis, M. Rooney, J. Y. Kim, Eiichi Hirose, S. J. Ives, M. Posiadala, Takayuki Tomaru, C. Strabel, M. G. Catanesi, J. Spitz, V. Kravtsov, K. Wong, R. Sulej, C. Mark, Robert Wilson, Takahiro Okamura, J. Argyriades, A.K. Ghosh, E. Rondio, P. Dinh Tran, J. Beucher, N. McCauley, K. K. Joo, T. Wachala, D. Terhorst, P. Stamoulis, A. Gaudin, W. Qian, C. J. Pearson, G. Kogan, J. Swierblewski, G. De Rosa, R. A. Owen, A. Badertscher, M. Macaire, Y. Takenaga, A. Konaka, J. Kameda, P. Przewlocki, Yusuke Koshio, B. E. Berger, Lester D.R. Thompson, F. Druillole, Ken Sakashita, M. Mezzetto, C. Angelsen, Antonin Vacheret, W. R. Kropp, M. Cadabeschi, J. F. Martin, M. Tzanov, C. J. Metelko, H. Kakuno, R. Bradford, Leonid Kurchaninov, J. R. Wilson, K. Sasaki, M. Bryant, D. Pierrepont, A. Murakami, Yu. Kudenko, D. Bishop, S. Sooriyakumaran, M. Usseglio, Justin Albert, N. Kulkarni, N. Abgrall, S. Greenwood, C. Hearty, Suyong Choi, Alastair Grant, Richard J.H. Smith, G. Mituka, M. Thorpe, F. Pierre, Yutaka Yamanoi, Hiroshi Yamaoka, A. Marchionni, R. A. Wendell, Vincenzo Berardi, Ewart W. Blackmore, P. T. Le, T. Kobayashi, S. Di Luise, A. Curioni, Tomoko Ariga, P. Baron, J. L. Ritou, S. Koike, M. Lenckowski, G. Vasseur, B. Still, M. Pfleger, K. B. Fransham, Masashi Tanaka, C. Hansen, T. B. Lawson, K. Iyogi, E. D. Zimmerman, Tomiyoshi Haruyama, K. P. Lee, M. Day, Robert Henderson, A. Longhin, J. Marteau, Z. Williamson, M. Iida, H. Kaji, Katsuki Hiraide, K. Olchanski, M. Ravonel, Michel Raymond, G. Christodoulou, K. Nakamura, B. Hartfiel, Leigh H. Whitehead, Masayuki Nakahata, Y. Uchida, T. Sekiguchi, Tatsushi Nakamoto, M. Besnier, G. Ganetis, Gavin Davies, L. Ludovici, C. Cavata, M. Sorel, S. Hastings, M. D. Haigh, C. W. Walter, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Département d'Electronique, des Détecteurs et d'Informatique pour la Physique (ex SEDI) (DEDIP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), T2K, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), K., Abe, N., Abgrall, H., Aihara, DE ROSA, Gianfranca, Palladino, Vittorio, Département d'Electronique, des Détecteurs et d'Informatique (ex SEDI) (DEDI), Abgrall, Nicolas, Argyriades, Jeremy, Blondel, Alain, Bravar, Alessandro, Dufour, Fanny, Ferrero, Andréa, Haesler, Alexis, Korzenev, Alexander, Murphy, Sébastien, Ravonel Salzgeber, Melody, and Wikstrom, Gustav

Subjects
Nuclear and High Energy Physics, Particle physics, Sterile neutrino, Physics - Instrumentation and Detectors, Neutrino oscillation, Physics::Instrumentation and Detectors, ddc:500.2, 7. Clean energy, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Long baseline, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Neutrinos, 010306 general physics, physics.ins-det, Instrumentation, QC, Physics, T2K, hep-ex, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, T2K experiment, J-PARC, Super-Kamiokande, Física, Neutrino detector, High Energy Physics::Experiment, Neutrino, Lepton
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

16. Simulation of a quantum Hall cryogenic current comparator resistance bridge

Author

K. Jones, T. B. Lawson, and M. D. Early

Subjects
Engineering, Wheatstone bridge, business.industry, Resonance, Quantum Hall effect, Instability, Noise (electronics), Cryogenic current comparator, law.invention, Control theory, law, Resistor, business, Servo
Abstract

A servo model of MSL's CCC resistance bridge has been developed that predicts a number of resonance peaks in the response not obvious from a trivial analysis and may explain some observed instability. Such a model is useful for exploring subtle frequency-dependant effects and is valuable for optimising servo performance. Changes to some component values and operating procedures are predicted to limit the measured resistance ratio error to

Published
2010

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

Author

S. E. Vahsen, T. B. Lawson, Niayesh Afshordi, Haley Louise Gomez, E. Tziaferi, A. St. J. Murphy, H. Nishimura, N. J. C. Spooner, F. Mayet, A. Takeda, J. Billard, J.A. Villar, K. Nakamura, A. Dushkin, Tracy R. Slatyer, P. Colas, Nitya Kallivayalil, B. Mccluskey, R. Vanderspek, Tatsuhiro Naka, T. Fusayasu, Arturo Rodriguez Rodriguez, C. Hagemann, Shigeto Kabuki, C. Ida, H. Wellenstein, G. Sciolla, T. Lamy, R. K. Yamamoto, J. Kadyk, H. Tomita, D. P. Snowden-Ifft, Sean Paling, M. E. Gomez, S. Cebrián, Robyn E. Sanderson, H. Kubo, G.G. Nicklin, S. Burgos, Jocelyn Monroe, E. H. Miller, M. Takahashi, J. Galán, T. Lin, D. Santos, Hiroyuki Sekiya, Kaori Hattori, T. Nakano, Toru Tanimori, Shunsuke Kurosawa, S. P. Ahlen, G. Luzón, Michael Gold, K. Ueno, Satoru Iwaki, A. C. Kaboth, K. Tsuchiya, Anne M. Green, William Fedus, T. Gamble, M. Pipe, I. Wolfe, E. R. Lee, Shawn Wesley Henderson, D. Dujmic, Matthew R. Robinson, Paolo Gondolo, Efrain J. Ferrer, H. Yegoryan, V. A. Kudryavtsev, Richard C. Lanza, I. G. Irastorza, Jose Rodríguez-Quintero, J. Forbes, Andrew Inglis, Jeremy Lopez, T. Manobu, A. Lee, O. Guillaudin, J. Turk, Ioannis Giomataris, B. Morgan, Peter H. Fisher, A. Petkov, E. J. Daw, Kojiro Taniue, T. Sahin, Nassim Bozorgnia, K. Niwa, T. Dafni, J D Vergados, C. Ghag, Joseph D. Parker, A. Takada, J. M. Carmona, M. Nakamura, D. Finkbeiner, Kentaro Miuchi, J. Martoff, T. Caldwell, D. Loomba, N. Sanghi, F.J. Iguaz, C. Grignon, D. Muna, A. Tomás, A. Sugiyama, O. Sato, Tatsuya Sawano, K. Pushkin, N. Higashi, James Battat, Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Current (mathematics), Field (physics), 010308 nuclear & particles physics, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Detector, Dark matter, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Atomic and Molecular Physics, and Optics, 3. Good health, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, astro-ph.CO, Sensitivity (control systems), 010306 general physics, Scaling, 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., 48 pages, 37 figures, whitepaper on direct dark matter detection with directional sensitivity

Published
2009

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

Author

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

Subjects
Physics, Wire chamber, Time projection chamber, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, Dark matter, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Electron, equipment and supplies, Particle detector, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Recoil, WIMP, Instrumentation, Axion, Mathematical Physics
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 m3 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 of 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

19. ZEPLIN-II limits on WIMP-nucelon interactions

Author

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

Subjects
Nuclear physics, Physics, Large Underground Xenon experiment, Xenon, chemistry, WIMP, Weakly interacting massive particles, Dark matter, chemistry.chemical_element, Cryogenic Dark Matter Search, Particle detector, Particle identification
Abstract

ZEPLIN II is a two‐phase xenon detector designed to detect dark matter in the form of Weakly Interacting Massive Particles (WIMPs). Following the first 31‐day underground run in Boulby Mine, UK, the collaboration published dark matter limits in January 2007; the first such limits using two‐phase xenon technology. We outline the key detector design, performance and results here.

Published
2009

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

Author

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

Subjects
Physics, Nuclear and High Energy Physics, Time projection chamber, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Astrophysics (astro-ph), Detector, FOS: Physical sciences, Astrophysics, 01 natural sciences, Particle detector, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Recoil, WIMP, 0103 physical sciences, Neutron source, Neutron, 010306 general physics, Instrumentation, Directional Recoil Identification from Tracks
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., 14 pages, 1 Table, 8 Figures

Published
2008

21. First limits on WIMP nuclear recoil signals in ZEPLIN-II: A two-phase xenon detector for dark matter detection

Author

N. J. C. Spooner, E. Tziaferi, I. Liubarsky, T. B. Lawson, G.G. Nicklin, M. J. Carson, W. Ooi, Peter Majewski, C. Bungau, P. K. Lightfoot, W. G. Jones, P.F. Smith, Rodney Walker, J.D. Lewin, V. Chepel, J. E. McMillan, R. J. Cashmore, T. Gamble, J. Pinto da Cunha, Max Robinson, T. J. Sumner, David B. Cline, G. Salinas, M. K. Joshi, S.J.S. Plank, A. Bewick, J. Gao, S. M. Paling, A. St. J. Murphy, Daniel Tovey, M.I. Lopes, A. Lindote, E.V. Korolkova, H. Chagani, A. S. Howard, C. Silva, G. J. Alner, F. Neves, B. Morgan, V. N. Solovov, V. A. Kudryavtsev, E. J. Daw, Hongwei Wang, D. Muna, R. Lüscher, J.C. Davies, C. Thorne, V. N. Lebedenko, K. Mavrokoridis, C. Ghag, N. J. T. Smith, R. M. Preece, D. C. R. Davidge, B. N. Edwards, T. Durkin, J. T. White, F.L.H. Wolfs, J. V. Dawson, J. J. Quenby, B. Camanzi, Henrique Araujo, F. Sergiampietri, APC - Neutrinos, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
[PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Dark matter, Population, chemistry.chemical_element, FOS: Physical sciences, Radon, Q1, Astrophysics, 01 natural sciences, 7. Clean energy, Particle detector, Nuclear physics, Recoil, Xenon, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Neutron, 010306 general physics, 10. No inequality, education, QC, Physics, education.field_of_study, 010308 nuclear & particles physics, Astrophysics (astro-ph), ZEPLIN-II, LIQUID XENON, Astronomy and Astrophysics, Radiation detectors, WIMPs, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], chemistry, Tracking and position-sensitive detectors, Supersymmetric partners of known particles, Neutron source, Scintillation detectors, Radiation Detectors, Liquid xenon
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

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

Author

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

Subjects
ARGON, ZEPLIN-III, Physics::Instrumentation and Detectors, Monte Carlo method, Dark matter, FOS: Physical sciences, Astronomy & Astrophysics, Q1, Astrophysics, dark matter, Particle detector, Nuclear physics, Data acquisition, Optics, radiation detectors, MONTE-CARLO, GEANT4, QC, Physics, Scintillation, Science & Technology, business.industry, PHYSICS, PARTICLES & FIELDS, Detector, Astrophysics (astro-ph), LIQUID XENON, Astronomy and Astrophysics, Reconstruction algorithm, TRANSPORT, WIMPs, Radiation detectors, Physical Sciences, Liquid xenon, business
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., Submitted to Astroparticle Physics

Published
2006

23. Status of ZEPLIN II and ZEPLIN III

Author

J. E. McMillan, V. A. Kudryavtsev, D. Cline, C. Bungau, I. Liubarsky, M. J. Carson, F. Sergiampietri, M. K. Joshi, W. G. Jones, J. Gao, R. Bissit, A. Bewick, J.D. Lewin, J. Seifert, T. Gamble, D. Davidge, X. Yang, B. Morgan, P. K. Lightfoot, E. J. Daw, H. Wang, Rodney Walker, J. Miller, J. C. Davis, J.V. Dawson, C. Ghag, G. J. Alner, T. B. Lawson, Sean Paling, Alex Murphy, J. J. Quenby, Daniel Tovey, James A. Maxin, R. M. Preece, V. N. Lebedenko, B. Camanzi, T. J. Sumner, G. Salinas, R. Lüscher, Nick Smith, N. J. C. Spooner, W. Ooi, A. S. Howard, Matthew R. Robinson, J. T. White, T. Durkin, Y. Chen, P. F. Smith, and Jackson Champer

Subjects
Physics, Particle physics, Large Underground Xenon experiment, Cold dark matter, ZEPLIN-III, Weakly interacting massive particles, Detector, Dark matter
Abstract

We describe the ZEPLIN II (30-kg) and ZEPLIN III (7-kg) discriminating dark matter detector using two-phase xenon designed for direct detection of cold dark matter in the form of Weakly Interacting Massive Particles. These two detectors are currently being commissioned. Both detector will begin operation in the Boulby Mine, UK in 2005. ZEPLIN II & III are capable of discriminating between nuclear recoils and background events and have a design reach up to two orders of magnitude beyond current limits. These two detectors will also serve as a step in the development program for a next-generation ton-scale detector.

Published
2006

24. LIMITS ON WIMP CROSS-SECTIONS FROM THE NAIAD EXPERIMENT AT BOULBY

Author

N. J. T. Smith, J. C. Barton, Alex Murphy, J. E. McMillan, Gavin Davies, T. B. Lawson, A. Nicholls, T. J. Sumner, B. Camanzi, J. Kirkpatrick, M. K. Joshi, R. J. Hollingworth, E. Tziaferi, V. N. Lebedenko, S. M. Paling, B. Morgan, R. M. Preece, C. Bungau, W. G. Jones, P.F. Smith, E. J. Daw, Matthew J. Lehner, M. J. Carson, I. Ivaniouchenkov, G. J. Alner, D. C. R. Davidge, T. Durkin, A. Bewick, J. J. Quenby, G.J. Homer, G.G. Nicklin, J. W. Roberts, N. J. C. Spooner, J. V. Dawson, Christopher D. P. Duffy, G.T.J. Arnison, S. P. Hart, P. K. Lightfoot, A. S. Howard, J.C. Davies, I. Liubarsky, Daniel Tovey, Henrique Araujo, T. Gamble, R. Lüscher, J.D. Lewin, Max Robinson, and V. A. Kudryavtsev

Subjects
Physics, WIMP, media_common.quotation_subject, Hot dark matter, Mixed dark matter, Dark matter, Warm dark matter, Scalar field dark matter, Astrophysics, Cosmology, Universe, media_common
Published
2005

25. NEUTRON BACKGROUND IN A TIME PROJECTION CHAMBER FOR WIMP SEARCHES

Author

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

Subjects
Nuclear physics, Physics, Particle physics, Time projection chamber, WIMP, Neutron
Published
2005

26. ZEPLIN I: FIRST LIMITS ON NUCLEAR RECOIL RATE

Author

J. E. McMillan, T. Gamble, G. J. Alner, Gavin Davies, D. C. R. Davidge, T. Durkin, J. W. Roberts, S. P. Hart, R. J. Hollingworth, J.D. Lewin, Manasvita Joshi, Max Robinson, G.G. Nicklin, T. B. Lawson, Daniel Tovey, R. Lüscher, J.C. Davies, G.T.J. Arnison, P. K. Lightfoot, C. Bungau, N. J. C. Spooner, A. S. Howard, J. V. Dawson, G.J. Homer, W. G. Jones, P.F. Smith, A. Bewick, J. C. Barton, V. A. Kudryavtsev, B. Camanzi, N. J. T. Smith, I. Liubarsky, B. Morgan, M. J. Carson, I. Ivaniouchenkov, A. Nicholls, J. J. Quenby, V. N. Lebedenko, Matthew J. Lehner, Henrique Araujo, T. J. Sumner, S. M. Paling, and R. M. Preece

Subjects
Nuclear physics, Physics, Recoil
Published
2005

27. Neutron background in large-scale xenon detectors for dark matter searches

Author

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

Subjects
Physics, Particle physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Dark matter, Detector, Nuclear Theory, chemistry.chemical_element, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Xenon, chemistry, Neutron flux, Neutron detection, Neutron, High Energy Physics::Experiment, Nuclear Experiment, Spontaneous fission
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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29. <font>NaIAD</font> EXPERIMENT FOR WIMP SEARCH AT BOULBY MINE AND RECENT RESULTS

Author

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

Subjects
Physics, Particle physics, WIMP, Dark matter
Published
2003

30. LATEST RESULTS FROM ZEPLIN I, A LIQUID XENON DETECTOR FOR DARK MATTER SEARCHES AT THE BOULBY MINE

Author

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

Subjects
Physics, Nuclear physics, Particle physics, Large Underground Xenon experiment, Xenon, chemistry, Dark matter, Detector, chemistry.chemical_element
Published
2003

31. The NAIAD experiment for WIMP searches at Boulby mine and recent results

Author

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

Subjects
Particle physics, Physics::Instrumentation and Detectors, WIMP, scintillation detectors, Dark matter, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Electron, Astronomy & Astrophysics, dark matter, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), LIMITS, SCINTILLATOR, NUCLEAR RECOIL, inorganic crystals, DETECTOR, Physics, Science & Technology, pulse shape analysis, Detector, PHYSICS, PARTICLES & FIELDS, Astrophysics::Instrumentation and Methods for Astrophysics, PULSE-SHAPE DISCRIMINATION, GRAN-SASSO, Astronomy and Astrophysics, CRYSTALS, Yield (chemistry), NAI(TL) SET-UP, Physical Sciences, Pulse shape analysis, High Energy Physics::Experiment, DARK-MATTER EXPERIMENTS, CROSS-SECTION
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

32. Study and suppression of anomalous fast events in inorganic scintillators for dark matter searches

Author

Sean Paling, I. Liubarsky, N. J. C. Spooner, G. Gerbier, S. P. Hart, J. Mallet, J. W. Roberts, V. N. Lebedenko, J.D. Lewin, T. Gamble, D. Davidge, Daniel Tovey, P. K. Lightfoot, J. J. Quenby, N. J. T. Smith, G. J. Alner, A. S. Howard, B. Ahmed, J.V. Dawson, T. B. Lawson, B. Morgan, T. J. Sumner, P. F. Smith, J. C. Barton, A. Bewick, M. J. Carson, I. Ivaniouchenkov, R. M. Preece, R. Lüscher, L. Mosca, Matthew J. Lehner, J. E. McMillan, W. G. Jones, M. K. Joshi, Charling Tao, Max Robinson, V. A. Kudryavtsev, Damoiseaux, Magali, Centre de Physique des Particules de Marseille (CPPM), and Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Particle physics, WIMP, Physics::Instrumentation and Detectors, scintillation detectors, Liquid paraffin, Dark matter, dark matters, FOS: Physical sciences, chemistry.chemical_element, Radon, ANNUAL MODULATION SIGNATURE, Astronomy & Astrophysics, Scintillator, Astrophysics, Physics, Particles & Fields, WIMPS, High Energy Physics - Experiment, Nuclear physics, Crystal, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], LIMITS, High Energy Physics - Experiment (hep-ex), 0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics, astro-ph, inorganic crystals, DETECTOR, Physics, Science & Technology, hep-ex, pulse shape analysis, Astrophysics (astro-ph), PULSE-SHAPE DISCRIMINATION, Nitrogen atmosphere, Astronomy and Astrophysics, NUCLEAR RECOILS, NAI(TL), Nuclear & Particles Physics, 0201 Astronomical And Space Sciences, chemistry, CSI(TL), [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Physical Sciences, BOULBY-MINE
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., 14 pages, 6 figures

Published
2002

33. UKDMC DARK MATTER SEARCH WITH INORGANIC SCINTILLATORS

Author

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

Subjects
Nuclear physics, Crystal, Physics, WIMP, chemistry, Liquid paraffin, Dark matter, Nitrogen atmosphere, chemistry.chemical_element, Radon, Scintillator
Abstract

The status of dark matter searches with inorganic scintillator detectors at Boulby mine is reviewed. Results of a test experiment with CsI(Tl) crystal are presented. The objectives of this experiment were to study anomalous fast events and ways to remove this background. We found clear indications that these events were due to surface contami- nation of crystals by alphas, probably from radon decay. A new array of unencapsulated NaI(Tl) crystals immersed in liquid paraffin or nitrogen atmosphere is under construction at Boulby. Such an approach allows us to control the surface of the crystals. Preliminary results of WIMP searches with NaI(Tl) detectors at Boulby are presented.

Published
2001

34. SCINTILLATION CHARACTERISTICS FOR LOW ENERGY RECOILS IN LIQUID XENON: PRELIMINARY RESULTS

Author

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

Subjects
Scintillation, Xenon, Materials science, Low energy, chemistry, Radiochemistry, chemistry.chemical_element
Published
2001

35. CsI(Tl) for WIMP dark matter searches

Author

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

Subjects
Physics, Quenching, Nuclear and High Energy Physics, Scintillation, Particle physics, Physics::Instrumentation and Detectors, Dark matter, chemistry.chemical_element, FOS: Physical sciences, Electron, Scintillator, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), WIMP, chemistry, Caesium, Instrumentation, Spin-½
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., 16 pages, 8 figures, to be published in Nucl. Instrum. and Meth. in Phys. Res. A

Published
2000

36. Measurements of scintillation efficiency and pulse shape for low energy recoils in liquid xenon

Author

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

Subjects
Particle physics, Nuclear and High Energy Physics, Quenching factor, Physics::Instrumentation and Detectors, WIMP, chemistry.chemical_element, FOS: Physical sciences, Electron, Astronomy & Astrophysics, Scintillator, Physics, Particles & Fields, High Energy Physics - Experiment, Nuclear physics, LIMITS, High Energy Physics - Experiment (hep-ex), 0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics, Recoil, Xenon, NUCLEAR RECOIL, Dark matter, Nuclear Experiment, DETECTOR, Physics, Scintillation, Range (particle radiation), Science & Technology, hep-ex, Double exponential function, Pulse shape, DARK-MATTER SEARCHES, NAI CRYSTAL, NAI(TL), Nuclear & Particles Physics, Exponential function, SODIUM, Physics, Nuclear, chemistry, DISCRIMINATION, Physical Sciences, Liquid xenon, BOULBY-MINE
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., 11 pages, including 5 encapsulated postscript figures

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37. Status of the Boulby Underground Laboratory

Author

G. J. Alner, T. B. Lawson, D. C. R. Davidge, R. M. Preece, V. A. Kudryavtsev, V. N. Lebedenko, T. Gamble, R. J. Hollingworth, N. J. T. Smith, G.G. Nicklin, N. J. C. Spooner, S. M. Paling, S. P. Hart, Manasvita Joshi, A. S. Howard, Max Robinson, J. Mulholland, B. Ahmed, J. E. McMillan, J. V. Dawson, G.J. Homer, P. K. Lightfoot, Daniel Tovey, B. Morgan, A. Bewick, I. Liubarski, J. W. Roberts, J. T. Sumner, W. G. Jones, P.F. Smith, R. Lüscher, J. J. Quenby, L.M. Yeoman, G. J. Arniston, J.D. Lewin, M. J. Carson, and J. C. Barton

Subjects
Mining engineering, Underground laboratory, Environmental science

38. ZEPLIN-I: A single phase liquid Xe detector for dark matter search

Author

T. B. Lawson, P. K. Lightfoot, I. Liubarsky, D. C. R. Davidge, W. G. Jones, P.F. Smith, C.D. Peak, J. W. Roberts, J.D. Lewin, V. A. Kudryavtsev, J. V. Dawson, Matthew J. Lehner, N. J. T. Smith, A. Bewick, R. M. Preece, J. E. McMillan, M. K. Joshi, C. Grigson, I. Ivaniouchenkov, T. J. Sumner, J. J. Quenby, V. N. Lebedenko, N. J. C. Spooner, G. J. Alner, R. Lüscher, S. P. Hart, Daniel Tovey, A. S. Howard, and B. Ahmed

Subjects
UK Dark Matter Collaboration, Physics, Range (particle radiation), Physics::Instrumentation and Detectors, Dark matter, Detector, Scintillator, Nuclear physics, Weakly interacting massive particles, Scintillation counter, High Energy Physics::Experiment, Neutron, Atomic physics, Nuclear Experiment
Abstract

The UK Dark Matter Collaboration is developing a series of liquid Xe detectors to search for the hypothetical weakly interacting massive particles (WIMPs) which may comprise a significant component of the Galactic dark matter. These detectors will be operated at a depth of 1100 m in the Boulby salt mine. The first of these detectors, ZEPLIN-I is a 1.7 litre single phase liquid Xe scintillation detector which employs pulse shape discrimination analysis to distinguish nuclear recoils due to WIMPs from electron recoils from background gamma interactions. The current status of ZEPLIN-I is presented in this paper. The detector design will be described and results discussed of tests on the detector performance using various types of radioactive sources in the 10 keV-1 MeV energy range. The light yield at the level of 1 photoelectron per 1 keV of deposited energy has been achieved. Clear discrimination between gamma initiated electron recoils and neutron initiated nuclear recoils has been observed. The discrimination potential below 100 keV, and subsequent expected sensitivity to dark matter particles, will be outlined.

39. Limits on WIMP cross-sections from the NAIAD experiment at the Boulby Underground Laboratory

Author

S. M. Paling, D. C. R. Davidge, V. N. Lebedenko, N. J. T. Smith, Gavin Davies, T. J. Sumner, G.G. Nicklin, Alex Murphy, A. Nickolls, G. J. Alner, N. J. C. Spooner, R. J. Hollingworth, C. Bungau, E. Tziaferi, W. G. Jones, A. Bewick, P.F. Smith, R. Lüscher, J.C. Davies, J.W. Roberts, R. M. Preece, S. P. Hart, I. Liubarsky, Christopher D. P. Duffy, Matthew J. Lehner, T. Gamble, B. Camanzi, J.D. Lewin, I. Ivaniouchenkov, Daniel Tovey, J. E. McMillan, M. J. Carson, M. Robinson, T. B. Lawson, V. A. Kudryavtsev, A. S. Howard, M. K. Joshi, J. Kirkpatrick, J. C. Barton, B. Morgan, E. J. Daw, J. J. Quenby, T. Durkin, Henrique Araujo, P. K. Lightfoot, J. V. Dawson, G.J. Homer, and G.T.J. Arnison

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Dark matter, FOS: Physical sciences, Q1, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), WIMP, Inorganic crystals, Neutralino, Pulse shape analysis, Underground laboratory, QC
Abstract

The NAIAD experiment (NaI Advanced Detector) for WIMP dark matter searches at the Boulby Underground Laboratory (North Yorkshire, UK) ran from 2000 until 2003. A total of 44.9 kg x years of data collected with 2 encapsulated and 4 unencapsulated NaI(Tl) crystals with high light yield were included in the analysis. We present final results of this analysis carried out using pulse shape discrimination. No signal associated with nuclear recoils from WIMP interactions was observed in any run with any crystal. This allowed us to set upper limits on the WIMP-nucleon spin-independent and WIMP-proton spin-dependent cross-sections. The NAIAD experiment has so far imposed the most stringent constraints on the spin-dependent WIMP-proton cross-section., Comment: 14 pages, 4 figures, to be published in Phys. Lett. B

40. The zeplin III detector: Results from surface calibrations

Author

Peter Majewski, D. C. R. Davidge, T. Durkin, G. J. Alner, Eirini Tziaferi, V. N. Solovov, Robert J. Walker, T. J. Sumner, M.I. Lopes, Blair Edwards, Henrique Araujo, A. Lindote, F. L. H. Wolfs, R. J. Hollingworth, T. B. Lawson, J.D. Lewin, P. K. Lightfoot, N. J. C. Spooner, K. Mavrokoridis, C. Celestino Silva, G.G. Nicklin, V. N. Stekhanov, C. Thorne, V. Chepel, T. Gamble, S.J.S. Plank, J. V. Dawson, Hui Wang, Elena Korolkova, Robert D. Preece, H. Chagani, A. A. Burenkov, S. M. Paling, Daniel Tovey, A. S. Howard, C. Ghag, B. Morgan, I. Liubarsky, M. J. Carson, A. Bewick, J. T. White, E. J. Daw, J. E. McMillan, N. J. T. Smith, David B. Cline, A. Murphy, D.Yu. Akimov, C. Bungau, W. G. Jones, P.F. Smith, A. G. Kovalenko, R. Lüscher, F. Neves, D. Muna, Manasvita Joshi, Max Robinson, J. Pinto da Cunha, V. A. Kudryavtsev, J. J. Quenby, I. S. Kuznetsov, and V. N. Lebedenko

Subjects
Surface (mathematics), Physics, Nuclear and High Energy Physics, Photomultiplier, Scintillation, Physics::Instrumentation and Detectors, ZEPLIN-III, business.industry, Dark matter, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Electrical engineering, Atomic and Molecular Physics, and Optics, Particle detector, Nuclear physics, Optics, Scintillation counter, Measuring instrument, Calibration, business
Abstract

ZEPLIN-III is a direct dark-matter search instrument using liquid xenon as a target.Both the scintillation light and the ionisation charge are measured.The instrument has been built and it is currently being testing in a surface laboratory.We present results from some of the initial testing, including design thermal control system verification, photomultiplier calibration (including spectral measurements with 60 keV photons from 241Am) and two-phase operation showing simultaneous measurement of scintillation and charge and position reconstruction. http://www.sciencedirect.com/science/article/B6TVD-4R68DXJ-11/1/34bf9254d1ff6c1c0eef471b141d2e68

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