performance of crtnt for sub-eev cosmoc ray measurement zhen cao ihep, beijing & univ. of utah,...
TRANSCRIPT
Performance of CRTNT forSub-EeV Cosmoc Ray Measurement
Zhen Cao IHEP, Beijing & Univ. of Utah, SLC
Aspen, CO, 04/2005
Outline
• Motivation of CRTNT project
• Design of CRTNT
• Status of prototype detector construction
• Simulation
• Aperture and event rate
• Conclusion
Motivation
• UHEτneutrinos
(Z.Cao et al., J. Phys. G: 31 (2005) 571-582)
• Sub-EeV Cosmic Rays
UHECR Energy Spectrum Structure
No Absolute Calibration
Poor Measurement on Composition
HiRes/MIA, HeverahPark,Cerenkov etc
CR arrival direction: Anisotropy
Millard CountyUtah/USA
~600 Scintillators(1.2 km spacing)
AGASA x 9
3 x Fluorescence StationsAGASA x 4
phase-1 TA Detector Configuration
Exp Res.
AGASA
1.60
TA SD ~1.00
TA FD 0.60
TA Hyb.
0.40
Low Energy ExtensionOf TA in Hybrid
TALETALE
TA
UHECR Research Strategyco-site, cross-calibration ,dedicate
TA/AugerTALECRTNT X
access?
CRTNT Detector Design& Prototype
• Mobile
• High sensitivity
• Big dynamic range
CRTNT DetectorCRTNT Detector
2.3m
2.3m
3.0m
•Shower imaging camera:
16x16 40mm hexagonal
Photonis PMT array
•A half of Connex box
•20 Φ600mm spherical
mirror, reflectivity 82%
Detector Structure
• Remote control door
• 256 pixels
• On board FADC electronics
• UV filter
• ~5m2 spherical Al reflector
Main tower detector12 telescopes
64º
21º 35º
10m 7m
F/C light Detector
Linux box
Detector Design: OpticsSpherical mirror: R=4490mmFocal plane camera: D=2305mmHexagonal pixel size: A=40mmMirror reflectivity: R=82%UV filter transmission: T=80%Physical optical spot: about the size of the pixel
Trigger/read out Electronics
50 MHz 10 bit FADC: High gain: 3 count/peLow gain: 0.3 count/pe
FPGA: single channel trigger 3.5σ
Digital adjustable HV supply 4 pole filter, x 30 Amp (H) x 3 Amp (L)
Detector Design: Electronics
848 pe440 ns
160 pe240 ns
• sky noise background: 40 photon/μsec/m2
• single channel trigger: signal/noise ratio>3.5σ• 320 ns running widow• 3 histories of 6μsec per event stored
320 ns window320 ns window
Characteristics of pulses
1000 events: 6X107GeV <E< 3X109GeV
Pulse Width (ns) # of pe’s per 20 ns bin
LG
HG
Status of Prototype Construction
• $0.3M for two prototype telescopes• 512 PMT’s calibration by Aug., • 2 modified connext boxes by June• 40 Φ600mm mirrors mounted by Aug.• Analog electronics by July.• Single channel trigger digital board by Sept.• 10 m2 UV filter by Sept.• Event trigger board & I/O by Nov.
Simulation & Performance
Simulation for CRTNT
• Detector configuration (3 site stereo)
• Proton primary
• Corsika+QGSJet based parameterization
• Single channel (tube) trigger: 3.5σ
• Telescope trigger: any 6 channels
• Event trigger: main tower && (one of sides)
• Cuts: edge events, Cerenkov light events
CRTNT Configuration
• Portable fluorescence detectors
• 3 site stereo
(12+2+2)
8km
3km
1-12
W1,2 E1,2
Cerenkov/edge events
Aperture of CRTNT
Impact Parameter
to the Tower Detector
AzimuthAngle
distribution
Zenith angle
distribution
Event distribution
Event Rate
Shower angular resolution
Conclusion
• The CRTNT is dedicated to the “second knee”
• All components for prototype are ordered
• Constr. /Testing in lab until the end of this year
• On-site testing/calibration/background next year
• Simulated aperture ~ 30 km2 sr @ 0.1EeV
• 20k events per year (>0.1EeV, flat aperture)
• 550 events per yr (>1EeV, full aperture) for cross-calibration with TALE