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Search Results: 1 - 10 of 117850 matches for " T. Bloxham "
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The Planetary Nebulae Spectrograph: the green light for Galaxy Kinematics
N. G. Douglas,M. Arnaboldi,K. C. Freeman,K. Kuijken,M. Merrifield,A. J. Romanowsky,K. Taylor,M. Capaccioli,T. Axelrod,R. Gilmozzi,J. Hart,G. Bloxham,D. Jones
Physics , 2002, DOI: 10.1086/342765
Abstract: Planetary nebulae are now well established as probes of galaxy dynamics and as standard candles in distance determinations. Motivated by the need to improve the efficiency of planetary nebulae searches and the speed with which their radial velocities are determined, a dedicated instrument - the Planetary Nebulae Spectrograph or PN.S - has been designed and commissioned at the 4.2m William Herschel Telescope. The high optical efficiency of the spectrograph results in the detection of typically ~ 150 PN in galaxies at the distance of the Virgo cluster in one night of observations. In the same observation the radial velocities are obtained with an accuracy of ~ 20 km/s
First results on double beta decay modes of Cd, Te and Zn isotopes with the COBRA experiment
The COBRA collaboration;Bloxham, T.;Boston, A.;Dawson, J.;Dobos, D.;Fox, S. P.;Freer, M.;Fulton, B. R.;G ling, C.;Harrison, P. F.;Junker, M.;Kiel, H.;McGrath, J.;Morgan, B.;Münstermann, D.;Nolan, P.;Oehl, S.;Ramachers, Y.;Reeve, C.;Stewart, D.;Wadsworth, R.;Wilson, J. R.;Zuber, K.
High Energy Physics - Phenomenology , 2007, DOI: 10.1103/PhysRevC.76.025501
Abstract: Four 1cm^3 CdZnTe semiconductor detectors were operated in the Gran Sasso National Laboratory to explore the feasibility of such devices for double beta decay searches as proposed for the COBRA experiment. The research involved background studies accompanied by measurements of energy resolution performed at the surface. Energy resolutions sufficient to reduce the contribution of two-neutrino double beta decay events to a negligible level for a large scale experiment have already been achieved and further improvements are expected. Using activity measurements of contaminants in all construction materials a background model was developed with the help of Monte Carlo simulations and major background sources were identified. A total exposure of 4.34 kg.days of underground data has been accumulated allowing a search for neutrinoless double beta decay modes of seven isotopes found in CdZnTe. Half-life limits (90% C.L.) are presented for decays to ground and excited states. Four improved lower limits have been obtained, including zero neutrino double electron capture transitions of Zn64 and Te120 to the ground state, which are 1.19*10^{17} years and 2.68*10^{15} years respectively.
First results on double beta decay modes of Cd, Te and Zn isotopes with the COBRA experiment
The COBRA collaboration,T. Bloxham,A. Boston,J. Dawson,D. Dobos,S. P. Fox,M. Freer,B. R. Fulton,C. G??ling,P. F. Harrison,M. Junker,H. Kiel,J. McGrath,B. Morgan,D. Münstermann,P. Nolan,S. Oehl,Y. Ramachers,C. Reeve,D. Stewart,R. Wadsworth,J. R. Wilson,K. Zuber
Physics , 2007, DOI: 10.1103/PhysRevC.76.025501
Abstract: Four 1cm^3 CdZnTe semiconductor detectors were operated in the Gran Sasso National Laboratory to explore the feasibility of such devices for double beta decay searches as proposed for the COBRA experiment. The research involved background studies accompanied by measurements of energy resolution performed at the surface. Energy resolutions sufficient to reduce the contribution of two-neutrino double beta decay events to a negligible level for a large scale experiment have already been achieved and further improvements are expected. Using activity measurements of contaminants in all construction materials a background model was developed with the help of Monte Carlo simulations and major background sources were identified. A total exposure of 4.34 kg.days of underground data has been accumulated allowing a search for neutrinoless double beta decay modes of seven isotopes found in CdZnTe. Half-life limits (90% C.L.) are presented for decays to ground and excited states. Four improved lower limits have been obtained, including zero neutrino double electron capture transitions of Zn64 and Te120 to the ground state, which are 1.19*10^{17} years and 2.68*10^{15} years respectively.
SkyMapper Filter Set: Design and Fabrication of Large Scale Optical Filters
Michael Bessell,Gabe Bloxham,Brian Schmidt,Stefan Keller,Patrick Tisserand,Paul Francis
Physics , 2011, DOI: 10.1086/660849
Abstract: The SkyMapper Southern Sky Survey will be conducted from Siding Spring Observatory with u, v, g, r, i and z filters that comprise glued glass combination filters of dimension 309x309x15 mm. In this paper we discuss the rationale for our bandpasses and physical characteristics of the filter set. The u, v, g and z filters are entirely glass filters which provide highly uniform band passes across the complete filter aperture. The i filter uses glass with a short-wave pass coating, and the r filter is a complete dielectric filter. We describe the process by which the filters were constructed, including the processes used to obtain uniform dielectric coatings and optimized narrow band anti-reflection coatings, as well as the technique of gluing the large glass pieces together after coating using UV transparent epoxy cement. The measured passbands including extinction and CCD QE are presented.
Structure of $^{13}$Be probed via secondary beam reactions
G. Randisi,A. Leprince,H. Al Falou,N. A. Orr,F. M. Marqués,N. L. Achouri,J. -C. Angélique,N. Ashwood,B. Bastin,T. Bloxham,B. A. Brown,W. N. Catford,N. Curtis,F. Delaunay,M. Freer,E. de Góes Brennand,P. Haigh,F. Hanappe,C. Harlin,B. Laurent,J. -L. Lecouey,A. Ninane,N. Patterson,D. Price,L. Stuttgé,J. S. Thomas
Physics , 2013, DOI: 10.1103/PhysRevC.89.034320
Abstract: The low-lying level structure of the unbound neutron-rich nucleus $^{13}$Be has been investigated via breakup on a carbon target of secondary beams of $^{14,15}$B at 35 MeV/nucleon. The coincident detection of the beam velocity $^{12}$Be fragments and neutrons permitted the invariant mass of the $^{12}$Be+$n$ and $^{12}$Be+$n$+$n$ systems to be reconstructed. In the case of the breakup of $^{15}$B, a very narrow structure at threshold was observed in the $^{12}$Be+$n$ channel. Contrary to earlier stable beam fragmentation studies which identified this as a strongly interacting $s$-wave virtual state in $^{13}$Be, analysis here of the $^{12}$Be+$n$+$n$ events demonstrated that this was an artifact resulting from the sequential-decay of the $^{14}$Be(2$^+$) state. Single-proton removal from $^{14}$B was found to populate a broad low-lying structure some 0.70 MeV above the neutron-decay threshold in addition to a less prominent feature at around 2.4 MeV. Based on the selectivity of the reaction and a comparison with (0-3)$\hbar\omega$ shell-model calculations, the low-lying structure is concluded to most probably arise from closely spaced J$^\pi$=1/2$^+$ and 5/2$^+$ resonances (E$_r$=0.40$\pm$0.03 and 0.85$^{+0.15}_{-0.11}$ MeV), whilst the broad higher-lying feature is a second 5/2$^+$ level (E$_r$=2.35$\pm$0.14 MeV). Taken in conjunction with earlier studies, it would appear that the lowest 1/2$^+$ and 1/2$^-$ levels lie relatively close together below 1 MeV.
The Wide Field Spectrograph (WiFeS): Performance and Data Reduction
Michael Dopita,Jonghwan Rhee,Catherine Farage,Peter McGregor,Gabe Bloxham,Anthony Green,Bill Roberts,Jon Nielson,Greg Wilson,Peter Young
Physics , 2010, DOI: 10.1007/s10509-010-0335-9
Abstract: This paper describes the on-telescope performance of the Wide Field Spectrograph (WiFeS). The design characteristics of this instrument, at the Research School of Astronomy and Astrophysics (RSAA) of the Australian National University (ANU) and mounted on the ANU 2.3m telescope at the Siding Spring Observatory has been already described in an earlier paper (Dopita et al. 2007). Here we describe the throughput, resolution and stability of the instrument, and describe some minor issues which have been encountered. We also give a description of the data reduction pipeline, and show some preliminary results.
7Be Solar Neutrino Measurement with KamLAND
A. Gando,Y. Gando,H. Hanakago,H. Ikeda,K. Inoue,K. Ishidoshiro,H. Ishikawa,Y. Kishimoto,M. Koga,R. Matsuda,S. Matsuda,T. Mitsui,D. Motoki,K. Nakajima,K. Nakamura,A. Obata,A. Oki,Y. Oki,M. Otani,I. Shimizu,J. Shirai,A. Suzuki,K. Tamae,K. Ueshima,H. Watanabe,B. D. Xu,S. Yamada,Y. Yamauchi,H. Yoshida,A. Kozlov,Y. Takemoto,S. Yoshida,C. Grant,G. Keefer,D. W. McKee,A. Piepke,T. I. Banks,T. Bloxham,S. J. Freedman,B. K. Fujikawa,K. Han,L. Hsu,K. Ichimura,H. Murayama,T. O'Donnell,H. M. Steiner,L. A. Winslow,D. Dwyer,C. Mauger,R. D. McKeown,C. Zhang,B. E. Berger,C. E. Lane,J. Maricic,T. Miletic,J. G. Learned,M. Sakai,G. A. Horton-Smith,A. Tang,K. E. Downum,K. Tolich,Y. Efremenko,Y. Kamyshkov,O. Perevozchikov,H. J. Karwowski,D. M. Markoff,W. Tornow,J. A. Detwiler,S. Enomoto,K. Heeger,M. P. Decowski
Physics , 2014, DOI: 10.1103/PhysRevC.92.055808
Abstract: We report a measurement of the neutrino-electron elastic scattering rate of 862 keV 7Be solar neutrinos based on a 165.4 kton-day exposure of KamLAND. The observed rate is 582 +/- 90 (kton-day)^-1, which corresponds to a 862 keV 7Be solar neutrino flux of (3.26 +/- 0.50) x 10^9 cm^-2s^-1, assuming a pure electron flavor flux. Comparing this flux with the standard solar model prediction and further assuming three flavor mixing, a nu_e survival probability of 0.66 +/- 0.14 is determined from the KamLAND data. Utilizing a global three flavor oscillation analysis, we obtain a total 7Be solar neutrino flux of (5.82 +/- 0.98) x 10^9 cm^-2s^-1, which is consistent with the standard solar model predictions.
A compact ultra-clean system for deploying radioactive sources inside the KamLAND detector
T. I. Banks,S. J. Freedman,J. Wallig,N. Ybarrolaza,A. Gando,Y. Gando,H. Ikeda,K. Inoue,Y. Kishimoto,M. Koga,T. Mitsui,K. Nakamura,I. Shimizu,J. Shirai,A. Suzuki,Y. Takemoto,K. Tamae,K. Ueshima,H. Watanabe,B. D. Xu,H. Yoshida,S. Yoshida,A. Kozlov,C. Grant,G. Keefer,A. Piepke,T. Bloxham,B. K. Fujikawa,K. Han,K. Ichimura,H. Murayama,T. O'Donnell,H. M. Steiner,L. A. Winslow,D. A. Dwyer,R. D. McKeown,C. Zhang,B. E. Berger,C. E. Lane,J. Maricic,T. Miletic,M. Batygov,J. G. Learned,S. Matsuno,M. Sakai,G. A. Horton-Smith,K. E. Downum,G. Gratta,Y. Efremenko,O. Perevozchikov,H. J. Karwowski,D. M. Markoff,W. Tornow,K. M. Heeger,J. A. Detwiler,S. Enomoto,M. P. Decowski
Physics , 2014, DOI: 10.1016/j.nima.2014.09.068
Abstract: We describe a compact, ultra-clean device used to deploy radioactive sources along the vertical axis of the KamLAND liquid-scintillator neutrino detector for purposes of calibration. The device worked by paying out and reeling in precise lengths of a hanging, small-gauge wire rope (cable); an assortment of interchangeable radioactive sources could be attached to a weight at the end of the cable. All components exposed to the radiopure liquid scintillator were made of chemically compatible UHV-cleaned materials, primarily stainless steel, in order to avoid contaminating or degrading the scintillator. To prevent radon intrusion, the apparatus was enclosed in a hermetically sealed housing inside a glove box, and both volumes were regularly flushed with purified nitrogen gas. An infrared camera attached to the side of the housing permitted real-time visual monitoring of the cable's motion, and the system was controlled via a graphical user interface.
Muon-induced backgrounds in the CUORICINO experiment
E. Andreotti,C. Arnaboldi,F. T. Avignone III,M. Balata,I. Bandac,M. Barucci,J. W. Beeman,F. Bellini,T. Bloxham,C. Brofferio,A. Bryant,C. Bucci,L. Canonica,S. Capelli,L. Carbone,M. Carrettoni,M. Clemenza,O. Cremonesi,R. J. Creswick,S. Di Domizio,M. J. Dolinski,L. Ejzak,R. Faccini,H. A. Farach,E. Ferri,F. Ferroni,E. Fiorini,L. Foggetta,A. Giachero,L. Gironi,A. Giuliani,P. Gorla,E. Guardincerri,T. D. Gutierrez,E. E. Haller,R. Kadel,K. Kazkaz,S. Kraft,L. Kogler,Yu. G. Kolomensky,C. Maiano,R. H. Maruyama,C. Martinez,M. Martinez,L. Mizouni,S. Morganti,S. Nisi,C. Nones,E. B. Norman,A. Nucciotti,F. Orio,M. Pallavicini,V. Palmieri,L. Pattavina,M. Pavan,M. Pedretti,G. Pessina,S. Pirro,E. Previtali,L. Risegari,C. Rosenfeld,C. Rusconi,C. Salvioni,S. Sangiorgio,D. Schaeffer,N. D. Scielzo,M. Sisti,A. R. Smith,C. Tomei,G. Ventura,M. Vignati
Physics , 2009, DOI: 10.1016/j.astropartphys.2010.04.004
Abstract: To better understand the contribution of cosmic ray muons to the CUORICINO background, 10 plastic scintillator detectors were installed at the CUORICINO site and operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV kg yr) (95% CL) was obtained on the cosmic ray-induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.
Measurement of the 8B Solar Neutrino Flux with the KamLAND Liquid Scintillator Detector
KamLAND Collaboration,S. Abe,K. Furuno,A. Gando,Y. Gando,K. Ichimura,H. Ikeda,K. Inoue,Y. Kibe,W. Kimura,Y. Kishimoto,M. Koga,Y. Minekawa,T. Mitsui,T. Morikawa,N. Nagai,K. Nakajima,K. Nakamura,M. Nakamura,K. Narita,I. Shimizu,Y. Shimizu,J. Shirai,F. Suekane,A. Suzuki,H. Takahashi,N. Takahashi,Y. Takemoto,K. Tamae,H. Watanabe,B. D. Xu,H. Yabumoto,E. Yonezawa,H. Yoshida,S. Yoshida,S. Enomoto,A. Kozlov,H. Murayama,C. Grant,G. Keefer,D. McKee,A. Piepke,T. I. Banks,T. Bloxham,J. A. Detwiler,S. J. Freedman,B. K. Fujikawa,K. Han,R. Kadel,T. O'Donnell,H. M. Steiner,L. A. Winslow,D. A. Dwyer,C. Mauger,R. D. McKeown,C. Zhang,B. E. Berger,C. E. Lane,J. Maricic,T. Miletic,M. Batygov,J. G. Learned,S. Matsuno,S. Pakvasa,M. Sakai,G. A. Horton-Smith,A. Tang,K. E. Downum,G. Gratta,K. Tolich,Y. Efremenko,Y. Kamyshkov,O. Perevozchikov,H. J. Karwowski,D. M. Markoff,W. Tornow,K. M. Heeger,F. Piquemal,J. -S. Ricol,M. P. Decowski
Physics , 2011, DOI: 10.1103/PhysRevC.84.035804
Abstract: We report a measurement of the neutrino-electron elastic scattering rate from 8B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5 MeV analysis threshold is 1.49+/-0.14(stat)+/-0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a 8B neutrino spectrum, this corresponds to a spectrum integrated flux of 2.77+/-0.26(stat)+/-0.32(syst) x 10^6 cm^-2s^-1. The analysis threshold is driven by 208Tl present in the liquid scintillator, and the main source of systematic uncertainty is due to background from cosmogenic 11Be. The measured rate is consistent with existing measurements and with Standard Solar Model predictions which include matter enhanced neutrino oscillation.
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