The DRIFT Dark Matter Experiment
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Transcript of The DRIFT Dark Matter Experiment
The DRIFTDark Matter Experiment
The DRIFTDark Matter Experiment
Jennie Davies University of Sheffield (UK)
IoP HEPP Conference - Dublin21st - 23rd March 2005
Jennie Davies University of Sheffield (UK)
IoP HEPP Conference - Dublin21st - 23rd March 2005
OutlineOutline
Why?
Dark matter
Who? What?
Where? When?
How?
The detector
Recent developments
Why?
Dark matter
Who? What?
Where? When?
How?
The detector
Recent developments
DRIFT... Why?DRIFT... Why?
To search for dark matter and identify a signal of galactic origin using directional information from nuclear recoil tracks.
To search for dark matter and identify a signal of galactic origin using directional information from nuclear recoil tracks.
DRIFT... Why?Dark Matter: The
Evidence
DRIFT... Why?Dark Matter: The
EvidenceObservational evidence
Rotational curves of galaxies
Gravitational lensing
Theoretical support
Supersymmetry
Observational evidence
Rotational curves of galaxies
Gravitational lensing
Theoretical support
Supersymmetry
DRIFT... Why?Dark Matter: The
Candidates
DRIFT... Why?Dark Matter: The
CandidatesBaryonic particle candidates
Non-baryonic particle candidates
Neutrinos
Weakly Interacting Massive Particles (WIMPs) - The stable LSP (neutralino)
Axions
Dark Energy
Baryonic particle candidates
Non-baryonic particle candidates
Neutrinos
Weakly Interacting Massive Particles (WIMPs) - The stable LSP (neutralino)
Axions
Dark Energy
DRIFT... Why?Dark Matter: WIMPs
DRIFT... Why?Dark Matter: WIMPs
Cold Dark Matter
Neutral
High mass (10 -1000 GeV)
Interact only very weakly
Postulated ‘WIMP Wind’
Daily fluctuations due to the Earth’s rotation
Cold Dark Matter
Neutral
High mass (10 -1000 GeV)
Interact only very weakly
Postulated ‘WIMP Wind’
Daily fluctuations due to the Earth’s rotation
DRIFT... Who?The DRIFT
Collaboration
DRIFT... Who?The DRIFT
CollaborationUK Dark Matter Collaboration
University of SheffieldUniversity of EdinburghImperial College, LondonRutherford Appleton Laboratory
Occidental College, Los Angeles, USATemple University, Philadelphia, USAUniversity of New Mexico, USAUniversity of Boston, USAUniversity of Thessaloniki, GreeceUniversity of Darmstadt, Germany
UK Dark Matter CollaborationUniversity of SheffieldUniversity of EdinburghImperial College, LondonRutherford Appleton Laboratory
Occidental College, Los Angeles, USATemple University, Philadelphia, USAUniversity of New Mexico, USAUniversity of Boston, USAUniversity of Thessaloniki, GreeceUniversity of Darmstadt, Germany
DRIFT... What?DRIFT... What?
DirectionalRecoilIdentificationFromTracks
DirectionalRecoilIdentificationFromTracks
DRIFT... What?DRIFT... What?
Negative Ion TimeProjection Chamber (NITPC)
Two back-to-back field cageswith a shared central cathode
Two readout planes - Multi-Wire Proportional Chambers (MWPCs)
Filled with CS2 gas at low pressure
Negative Ion TimeProjection Chamber (NITPC)
Two back-to-back field cageswith a shared central cathode
Two readout planes - Multi-Wire Proportional Chambers (MWPCs)
Filled with CS2 gas at low pressureMartoff et al. NIM-A 440 (2000) 355
DRIFT... Where?DRIFT... Where?
Boulby mineBoulby mine
Cleveland Potash Ltd.
DRIFT... When?DRIFT... When?
DRIFT-I
Underground in 2001
Data taking 2001-2004
Shielding installed 2004
Decommissioned 2004
DRIFT-I
Underground in 2001
Data taking 2001-2004
Shielding installed 2004
Decommissioned 2004
DRIFT... When?DRIFT... When?
DRIFT-IIUnderfloor shielding Autumn 20041st vessel u/g December 20041st detector u/g February 2005Further modules to go u/g throughout 2005 and on
DRIFT-IIUnderfloor shielding Autumn 20041st vessel u/g December 20041st detector u/g February 2005Further modules to go u/g throughout 2005 and on
DRIFT... How?DRIFT... How?
Nuclear recoils (elastic scattering)
Low energy ionisation
0.01 - 1 kg-1 day-1
Directionally sensitive
IMPORTANT:
Background reduction
gammas, alphas, neutrons etc.
require << 1 recoil per year
Nuclear recoils (elastic scattering)
Low energy ionisation
0.01 - 1 kg-1 day-1
Directionally sensitive
IMPORTANT:
Background reduction
gammas, alphas, neutrons etc.
require << 1 recoil per year
Carson et al. Astrop. Phys. 21 (2004) 667Carson et al. hep-ex/0503017 (accepted to
NIM-A)
SimulationsSimulations
Using SOURCES, GEANT4 and FLUKA
Neutron energy spectra (U & Th contamination)
Muon-induced neutrons
Geometry and particle tracking
Using SOURCES, GEANT4 and FLUKA
Neutron energy spectra (U & Th contamination)
Muon-induced neutrons
Geometry and particle tracking
SimulationsSimulations
Single and grouped DRIFT modules
Hydrocarbon neutron shielding
Reduce recoils due to neutron background to < 1 per year per module
Single and grouped DRIFT modules
Hydrocarbon neutron shielding
Reduce recoils due to neutron background to < 1 per year per module
SourceRecoil rate per
module per year (10-50 keV)
Recoil rate per 20 modules per year (10-50 keV)
Recoil rate per 10 kg per year
(10-50 keV)
Rock (40 g/cm2 CH2) 0.01 0.2 0.6
Detector components 0.06 1.3 3.8
Muon-induced 0.12 2.4 7.2
TOTAL 0.19 3.9 11.6
Data AnalysisData Analysis
DRIFT-IDRIFT-I
Snowden-Ifft et al. NIM-A 498 (2003) 155
Alner et al. NIM-A 535 (2004) 644
Data AnalysisData Analysis
Commissioning of the first DRIFT-II detector has been performed at Occidental College, L.A.
Initial calibration and background runs successful
Data analysis software is progressing as early data is being taken
Waveform plotting and data reduction
Parameter calculation and plotting
Software cuts in progress
Commissioning of the first DRIFT-II detector has been performed at Occidental College, L.A.
Initial calibration and background runs successful
Data analysis software is progressing as early data is being taken
Waveform plotting and data reduction
Parameter calculation and plotting
Software cuts in progress
55Fe gamma55Fe gamma
Cosmic neutronCosmic neutron
AlphaAlpha
Looking ahead ...Looking ahead ...
DRIFT-II
In progress
DRIFT-III
towards 1000 kg
target mass
Plus
Further improved simulations
Charge readout R & D
Much data taking and analysis
DRIFT-II
In progress
DRIFT-III
towards 1000 kg
target mass
Plus
Further improved simulations
Charge readout R & D
Much data taking and analysis