antonis leisos a sea top infrastructure for calibrating an underwater neutrino telescope the...
TRANSCRIPT
Antonis LeisosAntonis Leisos
A sea top infrastructure for A sea top infrastructure for calibrating an underwater calibrating an underwater
neutrino telescopeneutrino telescope
• the calibration principle using atmospheric showersthe calibration principle using atmospheric showers
• construction and performance of the prototype detector stationconstruction and performance of the prototype detector station
• Monte Carlo Studies Monte Carlo Studies
TeV Particle Astrophysics 2007
27-31 August 2007 Venice, Italy
G. Bourlis, P. Christopoulou, N. A. B. Gizani, A. Leisos, P. Razis ,A. G. Tsirigotis and S.E. Tzamarias
1 km
2 km
SPASE air shower arrays
calibration of AMANDA angular resolution and pointing !
resolution Amanda-B10 ~ 3.5°
spase-amanda
IceCube IceTop
The General Idea…
•Angular offset
•Efficiency
•Resolution
•Position
Physics ?
C.R. composition
UHE ν - Horizontal Showers
Veto atmospheric background – Study background
~4km
~20km
Isotropic on the top of the atmosphere
BUT …
~ coscos
dN
d
Pierre Auger: M. Are et al. Ast.Part. 14: 109-120 2000
0 23 4km instrumented area
17
0 2
for detection Ε 6×10 eV
θ 80 0.35/km /year 1.4showers/year
Haverah Park (www.ast.leeds.ac.uk/haverah/havpark.html):
12km2 effective area and 2π coverage in φ
for 10 years operation less than 100 detected showers with 0θ 80
reweightingBlind fit
Okada model NESTOR: muon flux @ 4000m
Floating stations
The Concept
3 stations with at 16 m2 scintillator detectors each
•Angular offset
•Efficiency
•Resolution
•Position
reweightingBlind fit
Okada model
~ coscos
dN
d
NESTOR: muon flux @ 4000m
HELYCON Station
GPSScintillator-PMT
Scintillator-PMT
Scintillator-PMT
DAQ
~20 m
1 m2
Single Station Set-Up
Triangulation
Shower Direction
Scintillator-PMT
4·(1W/counter)+30W(PC+electronics)
Simulation Tools
CORSIKA(Extensive Air Shower
Simulation)
GEANT4(Scintillation, WLS & PMT response)
Fast Simulation also available
Simulation Tools
DAQSIM(DAQ Simulation)
HOUANA(Analysis &
Track Reconstruction)
Time (ns)
Height (mV)
Zentih (degrees)
Simulation Tools
GEANT4Muon Propagation to KM3
HOU-KM3Muon track (s) reconstruction
dm
L-dm
(Vx,Vy,Vz) pseudo-vertex
dγ
d
Track Parameters
θ : zenith angle φ: azimuth angle (Vx,Vy,Vz): pseudo-vertex coordinates
θc
(x,y,z)
Monte Carlo Studies- Outlook 1014 - 5·1015 eV
E~ 1014 - 5·1015 eV: 2500 showers/m2/year
Single station detection: 351m2 effective area (depends on geometry and selection cuts)
Multi-Station: separation <100m, better resolution
E> 1016 eV: 1 shower/m2/year
TO BE STUDIED
35% of the detected showers include a muon which arrives at the Neutrino Telescope (depth 4000m) with an energy >300GeV
General Remark: 3 stations operating for 10 days can identify an angular offset with an accuracy of 0.15o
Specifically…Specifically…
Monte Carlo Studies
Depends on:
Detector separation
Selection criteria
Shower direction
Typical Values
1) No cut: σ= 4.5ο
2) Total Collected Charge > 10 mips: σ=2.22ο
3) Total Collected Charge > 25 mips: σ=1.33ο
4) Total Collected Charge > 30 mips: σ=1.2ο
Atmospheric shower simulation by CORSIKA - muon transportation to the detector DEPTH by GEANT4 - Sea-Top Detector detailed simulation GEANT4_HOU
PRELIMINARY
Θrec-Θtrue
Angular Resolution inSingle Shower Reconstruction
Multi Station Set upimprove resolution – higher energies
GPS Synchronisation
Δt <±6ns using sawtooth correction
curvature
thickness
Total collected charge [pe]
Tim
e D
ela
y (
ns
)T
ime
Sp
rea
d (
ns
)
Multi-Station Operation Monte Carlo Studies in Progress
Total collected charge [pe]
The HELYCON Detector Module
Scintillator 2
Scintillator 3
GPS timestamp
Station Server
Scintillator 3
HELYCON ReadOut Electronics
GPS Input
USB PortTrigger Ouput4 PMT Signal Inputs
25ps accuracy TDC
HPTDC
• 32 channels (LR) – 8 Channels (HR)
•25ps (HR) to 800 ps (LR) accuracy
•Self Calibrating
D. Loucas INP DEMOKRITOS
Response to Showers
Discriminator
(1.5 MIP)
Trigger
Input A
Input B
~10m
trigger arrival time
~60 mip’s
~50 mip’s
14.2ns
5.4ns
θ=31ο ± 8ο
Response to Minimum Ionizing Particles
Scintillator A
Scintillator B
Lead
DAQ based on TDS5052 Tektronix (5 Gsamples/s)
discriminators
Inputs
Trigger
Response to a MIP
DAQ S/W based on LabView
On-Line analysis - distributions
Charge (in units of mean p.e. charge)
At the Detector Center
Data
- Monte Carlo Prediction
Detailed Monte Carlo description
PRELIMINARY
Digitized Waveforms saved on hard disk
Response to a MIP
Detector Uniformity (the worst case)
Charge (in units of mean p.e. charge)
X Y
Typical Mean Numb. of p.e. per m.i.p. : 23 (± 16% variation)
PRELIMINARY
Response to a MIP
Detector Uniformity - Timing
Scintillator A
Scintillator B
Lead
discriminators
Inputs
Trigger
ΔΤ consistent with the difference of optical path (fiber refractive index n=1.6)
PRELIMINARY
Timing vs Pulse Hight
thickness
Input A
Input B
Discriminator
(1.5 MIP)
Trigger
Slewing
Resolution
Response to Showers
Trigger Detectors >1 mip
Detectors A.and.B > 0.5 mip’s
~ coscos
8.5 0.4
dN
d
zenith angle [degrees] zenith angle [degrees]
~ coscos
9.4 0.6
dN
d
Trigger Detectors > 1 mip
Detectors A.and.B > 1.5 mip’s
α=9.4±0.2
PRELIMINARY PRELIMINARY
Lab Measurements (a)
Discriminator
(1.5 MIP)Input C Trigger
A1
A2
A3
B1
B2
B3θΑ-θΒ
μ=-0.1±0.3
σ=7.6 ± 0.2
Pull
• Deposited Charge per counter > 4 mips 6 Active counters
μ=-0.06±0.05
σ=1.02 ± 0.03
MC -Data Data
___ M.C. Prediction
Lab Measurements (b)
Discriminator
(1.5 MIP)Input C Trigger
A1
A2
A3
B1
B2
B3
• Deposited Charge per counter > 4 mips 6 Active counters
μ=0.1±0.6
σ=4.5 ± 0.5
θm-θtr
Pull
μ=0.01±0.1
σ=0.9 ± 0.1
MC PredictionGROUP A
GROUP Bμ=0.3±0.8
σ=5.2 ± 0.8
θm-θtr
Pull
μ=0.02±0.1
σ=0.9 ± 0.1
DATA
δθ=4.6
DATA
δθ=5.6
dt=0
16m2 Scintillator Station
19m
19m
5m
1 m2 Scintillation Counter
dt1
dt2
dt3
2
exp2 i
hits dt
dt dt
Time corrections
deposited charge (mip)
delay (ns)
delay spread (ns)
deposited charge (mip)
Time residual
Time Residual meas true
dt
dt dt
Detection Efficiency
Distance from Shower Impact (meters)
Distance from Shower Impact (meters)
Efficiency
Events
Number of Active Counters (trigger)
A hit is considered when there is more than 4 mips deposited charge
Muon Propagation
μ track
km3
Geant Simulation
(propagation & Energy Loss)
Accepted if muon with E>2TeV goes through
km3
Muon Track Reconstruction
(A. Tsirigotis talk)
Zenith angle < 13 deg
Muon vs Shower Axis
muon primaryθ - θ (deg) μ-shower Space angle (deg)
Primary Zenith Angle Resolution
reconstructed true
Θ
θ - θ
σreconstructed trueθ - θ (deg)
• Deposited Charge per counter > 4 mips
• Number of Hits > 10
Primary Azimuth and Space angle Resolution
reconstructed trueφ - φ (deg) Space angle (deg)
• Deposited Charge per counter > 4 mips Number of Hits > 10
Performance Plots
Minimum number of Active counters
Minimum number of Active countersMinimum number of Active counters
2Effective Area (m )
θ resolution (deg)
Telescope Offset Resoltuion (deg)
Charge
Time (ns)Charge (in units of mean p.e. charge)
At the Detector Center
Data
- Monte Carlo Prediction
Scintillator A
Scintillator B
Lead
discriminators
Inputs
Trigger
Data
___ M.C. Prediction
Charge parameterization
Distance from shower core (m) Distance from shower core (m)
2Mean density (mip/m )2RMS density (mips/m )
2
( ) 1 11000
a h a
M M
r r rr C
R R
AGASA parameterization (S. Yoshida et al., J Phys. G: Nucl. Part. Phys. 20,651 (1994)
Parameters depend on
(θ, Ε, primary)
“Mean particle density registered by an active
counter”
Primary Impact determination
total charge collected (mip)
Impact Resolution (m)
Impact x (m)
Absolute Position resolution ~ 0.5 m
Performance Plots
Minimum number of Active counters
Minimum number of Active countersMinimum number of Active counters
2Effective Area (m )
Spatial Resolution (m)
Telescope Offset Resoltuion (deg)
Telescope Resolution
Telescope resolution ~ 0.1 deg
Surface Area resolution ~ 1 deg
Telescope’s resolution measurement Impossible
Inter calibration
σ=0.014
σ=0.094
σ=0.062
Conclusions
The operation of 3 stations (16 counters) for 10 days will provide:
• The determination of a possible offset with an accuracy ~ 0.05 deg
• The determination of the absolute position with an accuracy ~ 0.6 m
• Efficiency vs Energy and Zenith angle…• Resolution No!