The Status of MINOS Mike Kordosky University College London for the collaboration.
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Transcript of The Status of MINOS Mike Kordosky University College London for the collaboration.
The Status of MINOS
Mike KordoskyUniversity College London
for the collaboration
Outline
● NuMI / MINOS introduction and physics goals
● MINOS Detector description● Cosmic Rays and atmospheric at the Far
Detector● Experience with beam running in the Near
Detector● Near term goals and Conclusion
What is MINOS?
● Main Injector Neutrino Oscillation Search
● Long (735 km) Baseline
● Intense Neutrino Beam (NuMI)
● Near detector @ Fermilab
● Far detector @ Soudan, MN
Neutrino beam
Near detector
Far detector
● Muon neutrino disappearance
● Electron neutrino appearance
● Sterile neutrino component
● Atmospheric neutrinos
MINOS will study:
MINOS is the :
MINOS Collaboration The collaboration on the Fermilab site
with Near Detector surface building in background
Argonne – Athens – Benedictine – Brookhaven – Caltech – Cambridge – Campinas – Fermilab – College de France – Harvard – IIT – Indiana – ITEP Moscow – Lebedev – Livermore – Minnesota, Twin Cities – Minnesota, Duluth – Oxford – Pittsburgh – Protvino – Rutherford Appleton – Sao Paulo – South Carolina – Stanford – Sussex – Texas A&M – Texas-Austin – Tufts – Univ. College London – Western Washington – William & Mary - Wisconsin
175 physicists
32 institutions
6 nations
Disappearance
Survival Probability
● “atmospheric” oscillations from a beam source
● strong test of alternative hypotheses
● Large improvement in m2 measurement
● primary limitation: protons on target
nominal 3yr run
Electron Neutrino Appearance
● Much interest in e appearance and value of
13
● Measurement very challenging with MINOS detector & NuMI beam!
● But, if 13
is close to CHOOZ limit, we will see a ~3 signal in about 3yrs of
running
● Otherwise, will improve current limit by factor of 2-3
NuMI Beam
120 GeV/c p on graphite target
Magnetic Hornsfocus K
677 m decay pipe p,K stopped
Near detector
Control neutrino spectrum-- Move horns-- Move target
Neutrinos at the Main Injector
Near Detector
● Steel + Scint.
● 1km from Target
● 0.98 kton
● 282 steel planes
● B=1.2 T
● 64-anode PMTs
● High Rates
● QIE electronics
– no deadtime!
Near detector during construction
Coil Hole
Sci. Plane
PMTs, QIE electronics
PurposeMeasure beam before oscillations
Predict Far detector spectrum
To Far detector
Beam
Far Detector
● Soudan, MN
● 735 km from source
● 5.4 kton
● 486 steel planes
● B=1.3 T
● 16-anode PMTs
● 8x multiplexed
● VA electronics
Far detector: completed July 2003
Field Coil
PurposeMeasure -CC, NCenergy spectra, rates
Search for e appearance
PMTs & Electronics
To Fermilab
Veto shield
Optical Readout
8m wide
CalDet in T7
1 m
Optical Cables
PMTs
Beam
● Ran @ CERN PS
– T11: 0.5-3.6 GeV/c
– T7: 0.5-10.0 GeV/c
– mixed p,e,pi,mu beams
● Sixty 1-m2 planes
● Light level ~ Near and Far
● No B-field
● Ran w/ Far & Near readout
● External PID: CER & TOF
The CalDet
Purpose:
- Measure Response & Resolution- Characterize Event Topology- Confront & optimze MC- Develop Calibration Procedure- Study Near vs. Far readout
Detector Technology
Special Thanks M. Proga
2.54cm Steel absorber (2.50cm in CalDet)
Scint. 1cm thick, 4.1 cm wide WLS Fibers
Multi-anode PMT
Fiber ''cookie''
Scint. Plane
Readout Cable
PMT DarkBox
● Tracking-sampling calorimeter
● Segmentation:
– 5.94cm longitudinal
– 4.1cm transverse
● Planes rotated +/- 90 deg
● WLS collects/routes light to PMTs
Atmospheric Neutrinos
48events Cosmic Rays
Ex: Upward going muons
● First underground detector with B-field
● Can distinguish vs.-bar oscillations
● First publication (FC and PC analysis) to be submitted this summer
Moon Shadow
● Have collected 1e7 cosmic-ray muons in the Far Detector
● Can be used to observe the moon's shadow
● Used to determine angular resolution: < 1degree
HE primary cosmic rays
Far Detector
Near Detector: Single Spills
LE beam ~3-4 events/1e13 ppp spill HE beam ~8 events/1e13 ppp spill
spectrometer multiplexedTwo views: “U vs. Z” and “V vs. Z”
Near Detector: Isolating Single Events
● continuous read-out for 18 s
● 18.9 ns timing resolution
● Single events isolated via timing and position: “Slicing” hit-time in spill (s)
hit-time in spill (s)
5 “batches”
Near Detector: Contained CC Event
hit-time in spill (s) ~1.5 GeV/c , ~1.1 GeV shower
Near Detector: Rock Muon
hit-time in spill (s) ~6.3 GeV/c
Near Detector: Event Vertices
● Neutrino event vertex for data collected in May
● Already enough events to observe detector structure
fiducial volume
Partially instrumented plane (m)
horizontal position (m)
vertical position (m)
Fully instrumented plane (m)
Near Detector: Muon Track Direction
● Figures show zenith and azimuthal angles of -CC muon
tracks
● Beam pointing towards Far Detector:
– Zenith: Downward ~3.3 degrees, cos()=0.06
– Azimuth: Slightly west of true north: =156 degrees
● Good agreement with expectations!
Near Detector: Energy Spectra
● Data collected for 3 target positions
● More than 1.3e5 -CC
events recorded in May!
Near Detector -CC
events
reconstructed neutrino energy (GeV)
Far Detector: First Event
● First Event observed in the Far Detector: March 20, 2005.
● Event consists of a muon emanating from the rock in front of the detector.
● Muon points back to Fermilab and was in time with a beam spill.
Next Step: Choice of Beam Energy
● Run with low energy beam for first few months (~1e20 POT)
● Conduct initial oscillation analysis to check beam energy
Summary
● MINOS is taking beam data!
● Both detectors and NuMI beam operating rather smoothly.
● More than 140k nm-CC events recorded in Near Detector during May!
● Beam neutrinos observed in Far Detector!
● Initial oscillation analysis after ~1e20 POT, used to check beam configuration.
● Forthcoming atmospheric neutrino analysis.