A Large High Altitude Air Shower Observatory
LHAASO ProjectZhen Cao
Institute of High Energy Physics, China, Beijing 100049
TeVPA, SLAC,2009
Yangbajing Valley in Tibet
YBJ, Tibet4300m a.s.l.
Outline
• Scientific Perspectives
• Tentative design of a detector array
• Performance
• Prototyping
• Conclusion
Scientific Problems and Possible Solutions
• TeVγray observation has an opportunity of finding CR origin: 80+ sources discovered– 50+ galactic sources: γat high energy (>30TeV) is crucial
(high sensitivity and high energy resolution)
– All-sky survey forγsource population is necessary
(full duty cycle, wide FOV and sufficient sensitivity)
• PeV CR spectra of individual composition– Bridge between space/balloon borne measurements and g
round based UHECR measurements
• Searching for Dark Matter galactic sub-structures
?
Hadronic model
Leptonic model
A Tentative Design of A Complex Detector Array
Three major components• 1km2 complex array forγrays and CRs >30TeV
– 1 km2 scintillation detector array– 40k m2 μdetector array– 28 C-telescopes– 1k m2 burst detector
• 90k m2 water Cerenkov detector for γ>100GeV
• Two MagicII telescopes
Large High Altitude Air Shower Observatory
Charge Particle
Arrayμdetector
Array
Water CArray
LHAASO Project: γastronomy and origin of CR
Wide FOVC-Telescope
Array&
Core DetectorArray
Contribution of Magic Coll.
Water Cherenkov Detector
μdetector
Ground Charge Particle Detector
250mm
250m
m
20mm
1.2m
1m
scintillator PMT WS fiberThick Iron Case2.3cm
Wide FOVCherenkovtelescopes
Shower Core Detector YACYAC detector detector Pb(7r.l.)Pb(7r.l.)
Fe(1cm)Fe(1cm)PlasticPlastic scintiscinti..
Cost Free high energy
(1EeV)extension
Tower CT: 16
μ : 100x400m2
Side Trigger CT: 2x4
Re-Configuration
Performance
• 1km2 array for γdetection >50TeV
• MagicII @ Tibet site
• WCDA for source survey
• CR (30TeV ~ 1EeV): both knees &
absolute energy scale
Forγastronomy
ARGO
?
Resolution for light and heavy composition
μ-content, Xmax and HE (>30TeV) shower particles
Proton Iron
For Proton and Helium:
1.5 m spacing
Nb>100 , any 5
(> 30 GeV)
For Iron:
3.75m spacing
Nb>100 , any 21
( > 30 GeV)
The keys are to lower threshold, making connections with direct measurements & measure spectra up to 100PeV
A bridge between balloon measurements and ground base UHECR experimentcovering both “knees” with absolute energy scale
Dark Matter-rays from the sub-halos
Reed et al, MNRAS357,82(2004)
LHAASO sensitivityLHAASO sensitivity
-rays from smooth bkg-rays from smooth bkg
source
sun GC
ARGO sensitivity
Prototyping• R/D budget: ~$1M
• Detector unit prototype @ IHEP
On Site Prototype Exp.
• 1% of the final configuration of LHAASO
ARGO Hall
预先研究进展
• 1% 规模实验计划
From S. P. SWORDY, Space Science Reviews 99: 85–94, 2001.
CR Energy Spectrum
(160k events)
resolution < 10%With bias<3%Core resolution <1m
Conclusion
• a ground based large and complexγ/CR observatory at high altitude (4300m a.s.l.) within 5~10 years– Complementary to CTA in γastronomy– Unique for CR measurements at Knees– Perhaps useful for DM detection
Perspectives on γAstronomy
• Survey the whole sky for γsources above 100GeV (>90% of area is never surveyed at a sensitivity of 0.03ICrab)
• Investigate detailed energy spectra for galactic sources above 30TeV, cosmic ray sources are expected to be identified
• Detailed morphologic investigation of discovered sources for acceleration mechanism. (>30GeV)
Domestic Collaboration(13 inst.) • ARGO collaboration:
– APC of IHEP (detector design, project organization)– Tibet Univ. ( FPM )– SW Jiaotong Univ. ( FPM: construction at high altitude)– Yunnan Univ. (PMT calib., optics) – Shandong Univ. (PMT calib.. Computing & Simulation)– Hebei Normal Univ. (Simulation)
• New collaborators– EPC of IHEP (KM2A electronics, DAQ)– USTC (WCDA electronics, trigger and PMT calib.) – PKU (computing, UHE CRs) – IAP (high Altitude Atmospheric Phys. )– CSSAR (Space weather monitoring and prediction)– NSMC (Space weather monitoring and prediction)– IMP (Biophys. & Environment )
• Communication Members (potential collaborators):– Tsinghua Univ. – Shanghai Jiaotong Univ.– Eastern Institute of Science and Technology – Nanking Univ.
International Collaboration • ARGO collaboration:
– Rome II Univ. ( RPC, Simulation, Slow Control )– Lecce Univ. ( CRs, electronics)– Napeli Univ. (DAQ) – Torino Univ. (ECAL, GRBs)– …..
• Magic collaboration:– Max Planck Institute (Germany) (electr., Simulation, analysis)– Padova Univ. (Italy) (Telescope, optics)– IFAE (Spain) (Telescope, analysis)– …..
• Heidelberg Univ. (phys. Analysis)• Communication Members (future collaborators):
– HAWC Coll. (WCDA)
You are invited to Lhaaso at Lhasa!
Large High Altitude Air Shower Observatory