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B. Cabrera,
R. Abusaidi,
D. S. Akerib, P. D. Barnes,
D. A. Bauer,
A. Bolozdynya,
P. L. Brink,
R. Bunker,
D. O. Caldwell,
J. P. Castle, [......],
A. Smith,
G. W. Smith,
R. W. Schnee,
A. H. Sonnenschein,
A. L. Spadafora,
W. Stockwell,
J. D. Taylor,
S. White,
S. Yellin,
B. A. Young
[show abstract]
[hide abstract]
ABSTRACT: We report on the latest results from the CDMS (cryogenic dark matter search) experiment. The experiment uses superconducting particle detectors, operated below 100 mK, to search for dark matter in the form of weakly interacting massive elementary particles or WIMPs. These detectors are either Si or Ge crystals, where the electron-hole production and the phonon production are measured for each event, allowing the discrimination of electron recoils (most backgrounds due to gammas and betas) from nuclear recoils (due to WIMPs and neutrons). We have recently reported new limits from the Stanford shallow site experiment (CDMS-I) which explore supersymmetric models where the lightest supersymmetric particle is often an excellent WIMP candidate. We will also report on the Soudan deep site facility for the CDMS-II experiment which is under construction, and on the status of the CDMS-II detector fabrication. © 2001 American Institute of Physics.
AIP Conference Proceedings. 10/2001; 586(1):107-118.
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R. W. Schnee,
R. Abusaidi,
D. S. Akerib, P. D. Barnes,
D. A. Bauer,
A. Bolozdynya,
P. L. Brink,
R. Bunker,
B. Cabrera,
R. M. Clarke,
P. Colling,
M. B. Crisler,
A. Cummings,
A. Da Silva,
A. K. Davies,
R Dixon,
B. L. Dougherty,
D. Driscoll,
S. Eichblatt,
J. Emes
[show abstract]
[hide abstract]
ABSTRACT: . The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spinindependent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV c 2 WIMP mass and, at > 75% CL, the entire 3 allowed region for the WIMP signal reported by the DAMA experiment. 1 Introduction Weakly Interacting Massive Particles (WIMPs) are an excellent candidate for the universe's nonbaryonic, cold dark matter [1]. WIMPs in our Galaxy would scatter o nuclei via the weak interaction, potentially allowing their direct detection. The expected spectrum of the resulting nuclei recoil energies is exponential with a characteristic energy of a few to tens of keV [2]. The expected event rate is model-dependent but is generic...
11/2000;
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R Abusaidi,
D S Akerib, P D Barnes,
D A Bauer,
A Bolozdynya,
P L Brink,
R Bunker,
B Cabrera,
D O Caldwell,
J P Castle, [......],
T Shutt,
A Smith,
G W Smith,
A H Sonnenschein,
A L Spadafora,
W Stockwell,
J D Taylor,
S White,
S Yellin,
B A Young
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data, accounting for the neutron background, give limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV/c2 WIMP mass and, at >75% C.L., the entire 3sigma allowed region for the WIMP signal reported by the DAMA experiment.
Physical Review Letters 06/2000; 84(25):5699-703. · 7.37 Impact Factor
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R. Abusaidi,
D. S. Akerib, P. D. Barnes,
D. A. Bauer,
A. Bolozdynya,
P. L. Brink,
R. Bunker,
B. Cabrera,
J. P. Castle,
R. M. Clarke, [......],
A. K. Davies,
R Dixon,
B. Dougherty,
D. Driscoll,
S. Eichblatt,
J. Emes,
D. Hale,
E. E. Haller,
J. Hellmig,
V. Mandic
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for WIMPs via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. CDMS data give limits on the spin-independent WIMP-nucleon elastic-scattering cross-section that exclude unexplored parameter space above 10 GeV c Gamma2 WIMP mass and, at ? 84% CL, the entire 3oe allowed region for the WIMP signal reported by 1 the DAMA experiment. PACS numbers: 95.35.+d, 14.80.-j, 14.80.Ly Typeset using REVT E X 2 Extensive evidence indicates that a large fraction of the matter in the universe is nonluminous, nonbaryonic and "cold" -- nonrelativistic at the time matter began to dominate the energy density of the universe [1--3]. Weakly Interacting Massive Particles (WIMPs) are an excellent candidate for nonbaryonic, cold dark matter [4,2]. Minimal supersymmetry provides a natural WIMP candidate in the form of the lightest superpartner, with a typi...
04/2000;
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S. R. Golwala,
R. Abusaidi,
D. S. Akerib, P. D. Barnes,
D. A. Bauer,
A. Bolozdynya,
P. Brink,
B. Cabrera,
D O Caldwell,
J. P. Castle, [......],
E. E. Haller,
J. Hellmig,
M. E. Huber,
J. Jochum,
F. P. Lipschultz,
J. Martinis,
S. W. Nam,
H. Nelson,
B. Neuhauser,
T. A. Perera
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Dark Matter Search (CDMS) employs massive ionization- and phonon-mediated detectors to search for WIMPs via their elastic scattering interactions with nuclei while discriminating against interactions by other background particles. Limits on the WIMP-nucleon scattering cross-section, based on 3.1 kg d of exposure, exclude new parameter space in the 10 to 30 GeV WIMP mass region and also a portion of the region allowed by the DAMA annual modulation search (Ref. 1). 1 Introduction There is extensive evidence that a large fraction of the matter in the universe is nonluminous. In recent years, there has been a growing consensus that the ratio of the matter density in the universe to the critical density, r m /r crit = W m , is greater than approximately 0.25. This is more than what can be accounted for by luminous matter, W lum ~ 0.003h -1 (Ref. 2), or even by all baryons, 0.006h -2 < W b , < 0.016h -2 (95% CL) (Ref. 3), and hence there is a need for nonbaryonic dark m...
11/1999;
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S. R. Golwala,
A. Dasilva,
R. J. Gaitskell,
J. Hellmig,
J. Jochum,
D. Seitz,
G. Smith,
A. L. Spadafora,
S. White,
M. C. Perillo Isaac, [......],
R. Dixon,
S. Eichblatt,
E. E. Haller,
V. Kuzminov,
J. Martinis,
K. D. Irwin,
T. Shutt,
A. Smith,
B. A. Young,
CDMS Collaboration
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Dark Matter Search (CDMS) aims to detect WIMPs in the
galactic halo by observation of elastic scattering interactions with
nuclei in germanium and silicon targets. CDMS uses novel cryogenic
detectors that actively reject typical radioactive backgrounds, and thus
is ultimately vastly more sensitive to WIMP interactions than previous
experiments. We present limits on the WIMP-nucleon elastic scattering
cross section based on data acquired during recent runs, reflecting
significant detector and background improvements.
11/1998; 30:1337.
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R. J. Gaitskell, P. D. Barnes,
A. Dasilva,
S. R. Golwala,
J. Jochum,
R. R. Ross,
B Sadoulet,
D. Seitz,
T. Shutt,
G Smith,
W. Stockwell,
R. Therrien,
S White,
A. Sonnenschein D. Bauer,
D. S. Akerib,
T. A. Perera,
R. Schnee,
B. A. Young,
V. Kuzminov,
V. Novikov
09/1998;
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R. W. Schnee,
D. S. Akerib,
A. Bolodyzynya,
T. A. Perera, P. D. Barnes,
D. A. Bauer,
D O Caldwell,
H. Nelson,
A. H. Sonnenschein,
S Yellin, [......],
B Sadoulet,
T. Shutt,
A. L. Spadafora,
W. K. Stockwell,
E. E. Haller,
W. B. Knowlton,
R. R. Ross,
A Smith,
G Smith,
B. A. Young
[show abstract]
[hide abstract]
ABSTRACT: WIMP-nucleon cross section that are comparable to much longer runs of other experiments. Current and future runs promise significant improvement, primarily due to improved detectors and reduced surface-electron backgrounds. 1 Introduction Observations of stars and galaxies over a large range of distance scales indicate that most of the matter in the universe is "dark," seen only through its gravitational effects. 1;2 Further observations imply that that much of the dark matter is non-baryonic and "cold." 3 Massive, stable (or long-lived) particles with weak-scale couplings, such as may exist under supersymmetry or other extensions to the standard model, would provide about the implied amount of non-baryonic cold dark matter. 4;5 The Cryogenic Dark Matter Search (CDMS) experiment is an attempt to detect these weakly-interacting massive particles (WIMPs) directly, as they pass thro
08/1998;
-
R. W. Schnee,
D. S. Akerib,
A. Bolodyzynya,
T. A. Perera, P. D. Barnes,
D. A. Bauer,
D O Caldwell,
H. Nelson,
A. H. Sonnenschein,
S Yellin, [......],
B Sadoulet,
T. Shutt,
A. L. Spadafora,
W. K. Stockwell,
E. E. Haller,
W. B. Knowlton,
R. R. Ross,
A Smith,
G Smith,
B. A. Young
[show abstract]
[hide abstract]
ABSTRACT: cant improvement, primarily due to improved detectors and reduced surface-electron backgrounds. 1 Introduction Observations of stars and galaxies over a large range of distance scales indicate that most of the matter in the universe is "dark," seen only through its gravitational effects. 1;2 Further observations imply that that much of the dark matter is non-baryonic and "cold." Massive, stable (or long-lived) particles with weak-scale couplings, such as may exist under supersymmetry or other extensions to the standard model, would provide about the implied amount of non-baryonic cold dark matter. 4;5 The Cryogenic Dark Matter Search (CDMS) experiment is an attempt to detect these weakly-interacting massive particles (WIMPs) directly, as they pass through cryogenic detectors on Earth. The experimental challenge is defined in part by considerations of specific WIMP models, the early Universe, and the properties of our Galaxy. If WIMPs exist they would now make up a major comp
08/1998;
-
R. W. Schnee,
D. S. Akerib, P. D. Barnes,
D. A. Bauer,
P. L. Brink,
B. Cabrera,
R. M. Clarke,
P. Colling,
M. B. Crisler,
A. Da Silva,
A. K. Davies,
S. Eichblatt,
K. D. Irwin,
E. E. Haller,
J. Jochum,
W. B. Knowlton,
V. Kuzminov,
V. Novikov
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Dark Matter Search experiment uses cooled germanium and silicon detectors for a direct search for weakly-interacting massive particles in our Galaxy. The novel detectors allow a high degree of background rejection by discriminating between electron and nuclear recoils through the simultaneous measurement of the energy deposited in phonons and ionization. Exposures on the order of one kilogramday from initial runs of our experiment yield (preliminary) upper limits on the WIMP-nucleon cross section that are comparable to much longer runs of other Preprint submitted to Elsevier Preprint 8 May experiments. Current and future runs promise significant improvement, primarily due to improved detectors and reduced surface-electron backgrounds. 1 Introduction Observations of stars and galaxies over a large range of distance scales indicate that most of the matter in the universe is "dark," seen only through its gravitational effects [1,2]. Further observations imply that that muc...
06/1998;
-
R. W. Schnee,
D. S. Akerib, P. D. Barnes,
D. A. Bauer,
P. L. Brink,
B. Cabrera,
R. M. Clarke,
P. Colling,
M. B. Crisler,
A. Da Silva, [......],
S. R. Golwala,
E. E. Haller,
J. Jochum,
W. B. Knowlton,
V. Kuzminov,
S. W. Nam,
V. Novikov,
M. J. Penn,
B Sadoulet,
T. Shutt
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Dark Matter Search experiment uses cooled germanium and silicon detectors for a direct search for weakly-interacting massive particles in our Galaxy. The novel detectors allow a high degree of background rejection by discriminating between electron and nuclear recoils through the simultaneous measurement of the energy deposited in phonons and ionization. Exposures on the order of one kilogramday from initial runs of our experiment yield (preliminary) upper limits on the WIMP-nucleon cross section that are comparable to much longer runs of other Preprint submitted to Elsevier Preprint 8 May 1998 experiments. Current and future runs promise significant improvement, primarily due to improved detectors and reduced surface-electron backgrounds.
06/1998;
-
R. J. Gaitskell,
D. S. Akerib, P. D. Barnes,
D Bauer,
P. Brink,
B. Cabrera,
D O Caldwell,
R. M. Clarke,
A. Dasilva,
A. K. Davies, [......],
R. Schnee,
D. Seitz,
T. Shutt,
G Smith,
A. Sonnenschein,
J. D. Taylor,
R. Therrien,
S White,
S Yellin,
B. A. Young
[show abstract]
[hide abstract]
ABSTRACT: The Cryogenic Dark Matter Search (CDMS) experiment utilizes novel cryogenic particle detectors for a direct search of dark matter particles in the form of WIMPs in our galaxy. The detectors are able to discriminate between nuclear and electron recoils through the simultaneous measurement of ionization and phonons. We report on the latest results from several kg-day exposure of Ge and Si detectors. Despite exposure times that are 100 times smaller than previous experiments, our sensitivity is comparable to the currently reported dark matter limits.
01/1998;
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B. A. Young,
T. Shutt,
D. Akerib,
É. Aubourg, P. D. Barnes,
A. Cummings,
A. Silva,
J. Emes,
E. E. Haller,
S. Margulies,
R. R. Ross,
B. Sadoulet,
G. Smith,
W. Stockwell,
S. White
[show abstract]
[hide abstract]
ABSTRACT: We have tested a new 60 gram germanium phonon and ionization detector to study incomplete charge collection effects in cryogenic detectors. An understanding of such effects is necessary to further improve the nuclear vs. electronic recoil discrimination capability of cryogenic detectors. The detector is operated at 20 mK. It has three concentric ionization channels, and four electric field shaping structures on its sides. Phonons are sensed using NTD Ge thermistors. First results obtained using this device and moveable radioactive sources of241Am and57Co will be presented.
Journal of Low Temperature Physics 10/1993; 93(3):393-398. · 1.19 Impact Factor
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W. Stockwell,
D. Yvon,
É. Aubourg, P. D. Barnes,
A. Cummings,
A. Silva,
B. Ellman,
R. R. Ross,
B. Sadoulet,
T. Shutt,
G. Smith,
C. Stubbs,
N. Wang,
S. White,
B. A. Young
[show abstract]
[hide abstract]
ABSTRACT: We have developed low noise voltage and low noise charge sensitive preamplifiers for use in dilution refrigerator experiments. The amplifiers use a JFET at 140K as the front end. Each JEET dissipates about 7 mW on the 4K heat sink. The flat noise of the voltage amplifier is 0.9 nV/Hz1/2, with the 1/f knee below 100 Hz. The charge amplifier noise is 500 eV with a total input capacitance of approximately 90 pF.
Journal of Low Temperature Physics 10/1993; 93(3):755-760. · 1.19 Impact Factor
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P. D. Barnes,
A. Silva,
É. Aubourg,
D. S. Akerib,
D. Bauer,
D. Borden,
B. Cabrera,
D. O. Caldwell,
B. Chugg,
A. Cummings, [......],
T. Shutt,
A. Smith,
G. Smith,
W. Stockwell,
J. Taylor,
S. White,
M. Witherell,
R. C. Wolgast,
S. Yellin,
B. A. Young
[show abstract]
[hide abstract]
ABSTRACT: An experimental search for dark matter particle candidates using cryogenic detectors requires a low radioactive background environment. We discuss the status of a cryogenic dark matter experiment to be performed in the Stanford Underground Facility. The detectors will be cooled in a specially designed cryostat connected to a modified side access Oxford 400 dilution refrigerator. Details of the cryostat design and its operating performance are presented. The effectiveness of the multi-level shield surrounding the cryostat, as well as the background levels we expect to achieve in the pilot experiment are discussed. Finally, we examine the limits which can be set on dark matter candidates with such an experiment.
Journal of Low Temperature Physics 01/1993; 93(3):791-796. · 1.19 Impact Factor
