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Search Results: 1 - 10 of 461887 matches for " A. Teymourian "
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Characterization of the Hamamatsu R11410-10 3-Inch Photomultiplier Tube for Liquid Xenon Dark Matter Direct Detection Experiments
K. Lung,K. Arisaka,A. Bargetzi,P. Beltrame,A. Cahill,T. Genma,C. Ghag,D. Gordon,J. Sainz,A. Teymourian,Y. Yoshizawa
Physics , 2012, DOI: 10.1016/j.nima.2012.08.052
Abstract: To satisfy the requirements of the next generation of dark matter detectors based on the dual phase TPC, Hamamatsu, in close collaboration with UCLA, has developed the R11410-10 photomultipler tube. In this work, we present the detailed tests performed on this device. High QE (>30%) accompanied by a low dark count rate (50 Hz at 0.3 PE) and high gain (10^7) with good single PE resolution have been observed. A comprehensive screening measurement campaign is ongoing while the manufacturer quotes a radioactivity of 20 mBq/PMT. These characteristics show the R11410-10 to be particularly suitable for the forthcoming zero background liquid xenon detectors.
Studies of a three-stage dark matter and neutrino observatory based on multi-ton combinations of liquid xenon and liquid argon detectors
K. Arisaka,P. Beltrame,C. W. Lam,P. F. Smith,C. Ghag,D. B. Cline,K. Lung,Y. Meng,E. Pantic,P. R. Scovell,A. Teymourian,H. Wang
Physics , 2011, DOI: 10.1016/j.astropartphys.2012.05.006
Abstract: We study a three stage dark matter and neutrino observatory based on multi-ton two-phase liquid Xe and Ar detectors with sufficiently low backgrounds to be sensitive to WIMP dark matter interaction cross sections down to 10E-47 cm^2, and to provide both identification and two independent measurements of the WIMP mass through the use of the two target elements in a 5:1 mass ratio, giving an expected similarity of event numbers. The same detection systems will also allow measurement of the pp solar neutrino spectrum, the neutrino flux and temperature from a Galactic supernova, and neutrinoless double beta decay of 136Xe to the lifetime level of 10E27 - 10E28 y corresponding to the Majorana mass predicted from current neutrino oscillation data. The proposed scheme would be operated in three stages G2, G3, G4, beginning with fiducial masses 1-ton Xe + 5-ton Ar (G2), progressing to 10-ton Xe + 50-ton Ar (G3) then, dependent on results and performance of the latter, expandable to 100-ton Xe + 500-ton Ar (G4). This method of scale-up offers the advantage of utilizing the Ar vessel and ancillary systems of one stage for the Xe detector of the succeeding stage, requiring only one new detector vessel at each stage. Simulations show the feasibility of reducing or rejecting all external and internal background levels to a level <1 events per year for each succeeding mass level, by utilizing an increasing outer thickness of target material as self-shielding. The system would, with increasing mass scale, become increasingly sensitive to annual signal modulation, the agreement of Xe and Ar results confirming the Galactic origin of the signal. Dark matter sensitivities for spin-dependent and inelastic interactions are also included, and we conclude with a discussion of possible further gains from the use of Xe/Ar mixtures.
Characterization of the QUartz Photon Intensifying Detector (QUPID) for Noble Liquid Detectors
A. Teymourian,D. Aharoni,L. Baudis,P. Beltrame,E. Brown,D. Cline,A. D. Ferella,A. Fukasawa,C. W. Lam,T. Lim,K. Lung,Y. Meng,S. Muramatsu,E. Pantic,M. Suyama,H. Wang,K. Arisaka
Physics , 2011, DOI: 10.1016/j.nima.2011.07.015
Abstract: Dark Matter and Double Beta Decay experiments require extremely low radioactivity within the detector materials. For this purpose, the University of California, Los Angeles and Hamamatsu Photonics have developed the QUartz Photon Intensifying Detector (QUPID), an ultra-low background photodetector based on the Hybrid Avalanche Photo Diode (HAPD) and entirely made of ultraclean synthetic fused silica. In this work we present the basic concept of the QUPID and the testing measurements on QUPIDs from the first production line. Screening of radioactivity at the Gator facility in the Laboratori Nazionali del Gran Sasso has shown that the QUPIDs safely fulfill the low radioactive contamination requirements for the next generation zero background experiments set by Monte Carlo simulations. The quantum efficiency of the QUPID at room temperature is > 30% at the xenon scintillation wavelength. At low temperatures, the QUPID shows a leakage current less than 1 nA and a global gain of 10^5. In these conditions, the photocathode and the anode show > 95% linearity up to 1 uA for the cathode and 3 mA for the anode. The photocathode and collection efficiency are uniform to 80% over the entire surface. In parallel with single photon counting capabilities, the QUPIDs have a good timing response: 1.8 +/- 0.1 ns rise time, 2.5 +/- 0.2 ns fall time, 4.20 +/- 0.05 ns pulse width, and 160 +/- 30 ps transit time spread. The QUPIDs have also been tested in a liquid xenon environment, and scintillation light from 57Co and 210Po radioactive sources were observed.
First Dark Matter Results from the XENON100 Experiment
The XENON100 Collaboration,E. Aprile,K. Arisaka,F. Arneodo,A. Askin,L. Baudis,A. Behrens,E. Brown,J. M. R. Cardoso,B. Choi,D. B. Cline,S. Fattori,A. D. Ferella,K. -L. Giboni,K. Hugenberg,A. Kish,C. W. Lam,J. Lamblin,R. F. Lang,K. E. Lim,J. A. M. Lopes,T. Marrodán Undagoitia,Y. Mei,A. J. Melgarejo Fernandez,K. Ni,U. Oberlack,S. E. A. Orrigo,E. Pantic,G. Plante,A. C. C. Ribeiro,R. Santorelli,J. M. F. dos Santos,M. Schumann,P. Shagin,A. Teymourian,D. Thers,E. Tziaferi,H. Wang,C. Weinheimer
Physics , 2010, DOI: 10.1103/PhysRevLett.105.131302
Abstract: The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter WIMPs scattering off 62 kg of liquid xenon in an ultra-low background dual-phase time projection chamber. In this letter, we present first dark matter results from the analysis of 11.17 live days of non-blind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the pre-defined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross-sections above 3.4 x 10^-44 cm^2 for 55 GeV/c^2 WIMPs at 90% confidence level. Below 20 GeV/c^2, this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.
The XENON100 Dark Matter Experiment
XENON100 Collaboration,E. Aprile,K. Arisaka,F. Arneodo,A. Askin,L. Baudis,A. Behrens,E. Brown,J. M. R. Cardoso,B. Choi,D. Cline,S. Fattori,A. D. Ferella,K. L. Giboni,A. Kish,C. W. Lam,R. F. Lang,K. E. Lim,J. A. M. Lopes,T. Marrodan Undagoitia,Y. Mei,A. J. Melgarejo Fernandez,K. Ni,U. Oberlack,S. E. A. Orrigo,E. Pantic,G. Plante,A. C. C. Ribeiro,R. Santorelli,J. M. F. dos Santos,M. Schumann,P. Shagin,A. Teymourian,E. Tziaferi,H. Wang,M. Yamashita
Physics , 2011, DOI: 10.1016/j.astropartphys.2012.01.003
Abstract: The XENON100 dark matter experiment uses liquid xenon (LXe) in a time projection chamber (TPC) to search for Xe nuclear recoils resulting from the scattering of dark matter Weakly Interacting Massive Particles (WIMPs). In this paper we present a detailed description of the detector design and present performance results, as established during the commissioning phase and during the first science runs. The active target of XENON100 contains 62 kg of LXe, surrounded by an LXe veto of 99 kg, both instrumented with photomultiplier tubes (PMTs) operating inside the liquid or in Xe gas. The LXe target and veto are contained in a low-radioactivity stainless steel vessel, embedded in a passive radiation shield. The experiment is installed underground at the Laboratori Nazionali del Gran Sasso (LNGS), Italy and has recently published results from a 100 live-days dark matter search. The ultimate design goal of XENON100 is to achieve a spin-independent WIMP-nucleon scattering cross section sensitivity of \sigma = 2x10^-45 cm^2 for a 100 GeV/c^2 WIMP.
Material screening and selection for XENON100
XENON100 Collaboration,E. Aprile,K. Arisaka,F. Arneodo,A. Askin,L. Baudis,A. Behrens,K. Bokeloh,E. Brown,J. M. R. Cardoso,B. Choi,D. Cline,S. Fattori,A. D. Ferella,K. L. Giboni,A. Kish,C. W. Lam,J. Lamblin,R. F. Lang,K. E. Lim,J. A. M. Lopes,T. Marrodan Undagoitia,Y. Mei,A. J. Melgarejo Fernandez,K. Ni,U. Oberlack,S. E. A. Orrigo,E. Pantic,G. Plante,A. C. C Ribeiro,R. Santorelli,J. M. F. dos Santos,M. Schumann,P. Shagin,A. Teymourian,D. Thers,E. Tziaferi,H. Wang,C. Weinheimer,M. Laubenstein,S. Nisi
Physics , 2011, DOI: 10.1016/j.astropartphys.2011.06.001
Abstract: Results of the extensive radioactivity screening campaign to identify materials for the construction of XENON100 are reported. This Dark Matter search experiment is operated underground at Laboratori Nazionali del Gran Sasso (LNGS), Italy. Several ultra sensitive High Purity Germanium detectors (HPGe) have been used for gamma ray spectrometry. Mass spectrometry has been applied for a few low mass plastic samples. Detailed tables with the radioactive contaminations of all screened samples are presented, together with the implications for XENON100.
Study of the electromagnetic background in the XENON100 experiment
XENON100 Collaboration,E. Aprile,K. Arisaka,F. Arneodo,A. Askin,L. Baudis,A. Behrens,K. Bokeloh,E. Brown,J. M. R. Cardoso,B. Choi,D. Cline,S. Fattori,A. D. Ferella,K. -L. Giboni,A. Kish,C. W. Lam,J. Lamblin,R. F. Lang,K. E. Lim,Q. Lin,S. Lindemann,M. Lindner,J. A. M. Lopes,K. Lung,T. Marrodan Undagoitia,Y. Mei,A. J. Melgarejo Fernandez,K. Ni,U. Oberlack,S. E. A. Orrigo,E. Pantic,G. Plante,A. C. C. Ribeiro,R. Santorelli,J. M. F. dos Santos,M. Schumann,P. Shagin,H. Simgen,A. Teymourian,D. Thers,E. Tziaferi,H. Wang,M. Weber,C. Weinheimer
Physics , 2011,
Abstract: The XENON100 experiment, located at the Laboratori Nazionali del Gran Sasso (LNGS), aims to directly detect dark matter in the form of Weakly Interacting Massive Particles (WIMPs) via their elastic scattering off xenon nuclei. We present a comprehensive study of the predicted electronic recoil background coming from radioactive decays inside the detector and shield materials, and intrinsic contamination. Based on GEANT4 Monte Carlo simulations using a detailed geometry together with the measured radioactivity of all detector components, we predict an electronic recoil background in the WIMP-search energy range (0-100 keV) in the 30 kg fiducial mass of less than 10e-2 events/(kg-day-keV), consistent with the experiment's design goal. The predicted background spectrum is in very good agreement with the data taken during the commissioning of the detector, in Fall 2009.
The CAPTAIN Detector and Physics Program
The CAPTAIN Collaboration,H. Berns,H. Chen,D. Cline,J. Danielson,Z. Djurcic,S. Elliott,G. Garvey,V. Gehman,C. Grant,E. Guardincerri,R. Kadel,T. Kutter,D. Lee,K. Lee,Q. Liu,W. Louis,C. Mauger,C. McGrew,R. McTaggart,J. Medina,W. Metcalf,G. Mills,J. Mirabal-Martinez,S. Mufson,E. Pantic,O. Prokofiev. Mufson,V. Radeka,J. Ramsey,K. Rielage,H. Sahoo,C. Sinnis,M. Smy,W. Sondheim,I. Stancu,R. Svoboda,M. Szydagis,C. Taylor,A. Teymourian,C. Thorn,C. Tull,M. Tzanov,R. Van de Water,H. Wang,C. Yanagisawa,A. Yarritu,C. Zhang
Physics , 2013,
Abstract: The Cryogenic Apparatus for Precision Tests of Argon Interactions with Neutrino (CAP- TAIN) program is designed to make measurements of scientific importance to long-baseline neutrino physics and physics topics that will be explored by large underground detectors. The CAPTAIN detector is a liquid argon TPC deployed in a portable and evacuable cryostat. Five tons of liquid argon are instrumented with a 2,000 channel liquid argon TPC and a photon detection system. Subsequent to the commissioning phase, the detector will collect data in a high-energy neutron beamline that is part of the Los Alamos Neutron Science Center to measure cross-sections of spallation products that are backgrounds to measurements of neutrinos from a supernova burst, cross-sections of events that mimic the electron neutrino appearance signal in long-baseline neutrino physics and neutron signatures to constrain neutrino energy reconstruction in LBNE's long-baseline program. Subsequent to the neutron running, the CAPTAIN detector will be moved to a neutrino source. Two possibilities are an on-axis run in the NuMI beamline at FNAL and a run in the neutrino source produced by the SNS. An on-axis run at NuMI produces more than one million events of interest in a two or three year run at neutrino energies between 1 and 10 GeV - complementary to the MicroBooNE experiment, which will measure similar interactions at a lower energy range - 0.5 to 2 GeV. At the SNS the neutrinos result from the decays stopped positively charged pions and muons yielding a broad spectrum up to 50 MeV. If located close to the spallation target, CAPTAIN can detect several thousand events per year in the same neutrino energy regime where neutrinos from a supernova burst are. Measurements at the SNS yield a first measurement of the cross- section of neutrinos on argon in this important energy regime.
Likelihood Approach to the First Dark Matter Results from XENON100
XENON100 Collaboration,E. Aprile,K. Arisaka,F. Arneodo,A. Askin,L. Baudis,A. Behrens,K. Bokeloh,E. Brown,T. Bruch,J. M. R. Cardoso,B. Choi,D. Cline,E. Duchovni,S. Fattori,A. D. Ferella,K. -L. Giboni,E. Gross,A. Kish,C. W. Lam,J. Lamblin,R. F. Lang,K. E. Lim,S. Lindemann,M. Lindner,J. A. M. Lopes,T. Marrodán Undagoitia,Y. Mei,A. J. Melgarejo Fernandez,K. Ni,U. Oberlack,S. E. A. Orrigo,E. Pantic,G. Plante,A. C. C. Ribeiro,R. Santorelli,J. M. F. dos Santos,M. Schumann,P. Shagin,A. Teymourian,D. Thers,E. Tziaferi,O. Vitells,H. Wang,M. Weber,C. Weinheimer
Physics , 2011, DOI: 10.1103/PhysRevD.84.052003
Abstract: Many experiments that aim at the direct detection of Dark Matter are able to distinguish a dominant background from the expected feeble signals, based on some measured discrimination parameter. We develop a statistical model for such experiments using the Profile Likelihood ratio as a test statistic in a frequentist approach. We take data from calibrations as control measurements for signal and background, and the method allows the inclusion of data from Monte Carlo simulations. Systematic detector uncertainties, such as uncertainties in the energy scale, as well as astrophysical uncertainties, are included in the model. The statistical model can be used to either set an exclusion limit or to make a discovery claim, and the results are derived with a proper treatment of statistical and systematic uncertainties. We apply the model to the first data release of the XENON100 experiment, which allows to extract additional information from the data, and place stronger limits on the spin-independent elastic WIMP-nucleon scattering cross-section. In particular, we derive a single limit, including all relevant systematic uncertainties, with a minimum of 2.4x10^-44 cm^2 for WIMPs with a mass of 50 GeV/c^2.
Implications on Inelastic Dark Matter from 100 Live Days of XENON100 Data
XENON100 Collaboration,E. Aprile,K. Arisaka,F. Arneodo,A. Askin,L. Baudis,A. Behrens,K. Bokeloh,E. Brown,T. Bruch,G. Bruno,J. M. R. Cardoso,W. -T. Chen,B. Choi,D. Cline,E. Duchovni,S. Fattori,A. D. Ferella,F. Gao,K. -L. Giboni,E. Gross,A. Kish,C. W. Lam,J. Lamblin,R. F. Lang,C. Levy,K. E. Lim,Q. Lin,S. Lindemann,M. Lindner,J. A. M. Lopes,K. Lung,T. Marrodán Undagoitia,Y. Mei,A. J. Melgarejo Fernandez,K. Ni,U. Oberlack,S. E. A. Orrigo,E. Pantic,R. Persiani,G. Plante,A. C. C. Ribeiro,R. Santorelli,J. M. F. dos Santos,G. Sartorelli,M. Schumann,M. Selvi,P. Shagin,H. Simgen,A. Teymourian,D. Thers,O. Vitells,H. Wang,M. Weber,C. Weinheimer
Physics , 2011, DOI: 10.1103/PhysRevD.84.061101
Abstract: The XENON100 experiment has recently completed a dark matter run with 100.9 live-days of data, taken from January to June 2010. Events in a 48kg fiducial volume in the energy range between 8.4 and 44.6 keVnr have been analyzed. A total of three events have been found in the predefined signal region, compatible with the background prediction of (1.8 \pm 0.6) events. Based on this analysis we present limits on the WIMP-nucleon cross section for inelastic dark matter. With the present data we are able to rule out the explanation for the observed DAMA/LIBRA modulation as being due to inelastic dark matter scattering off iodine at a 90% confidence level.
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