1. Institute of High Energy Physics, CAS
The 4th Workshop of France China Particle Physics Laboratory
Large High Altitude Air Shower Observatory (LHAASO) Project and its present progress
Xiangdong SHENG
Institute of High Energy Physics, CAS
April , 2011

2. Outline 1. Scientific Problems
2. Design of the complex experiment of LHAASO project
3. Experimental progress of the prototypes
4. Site preparation and status of proposing
5. Conclusion

3. A centennial puzzle: Origin of high energy cosmic rays
The only matter from the universe
P、He…C、N、O…Mg、Al、Si…Fe…
neutrinos
few e, , …
All particle spectrum : power law
Energy range: >10 orders
Flux: >30 orders
2 Knees, 1 Ankle, GZK cutoff
Messenger of：particle acceleration and propagation, astronomical objects: forming and evolution, inner structure and environment, medium and background…
Origin is the key question, while the Sun is the only known source (E < 100GeV)
How to study? Spectrum Energy Distribution、composition、anisotropy
Fig. All particle spectrum

4. Origin of UHE cosmic rays
1. Scientific Problems
EHE cosmic ray
HIRES，AUGER
TA/TALE
50km
VHE γ、EHE CRs and Neutrinos can reserve the primary direction information.
VHE γ Astronomy
HESS，MAGIC
YBJ，MILAGRO
Origin of UHE
cosmic rays
VHE/UHE ν astronomy
ICECUBE，KM3
CRTNT，NUTEL，
ANITA

5. Cosmic ray study: Energy above the “knee”
Anisotropy: AGN & EHE CRs ( Auger)
Spectra Energy Distribution: energy scale (calibration, interaction model), narrow
Composition: inconsistency
Anisotropy: poor statistics, confirmation

6. The “Knee” — a 50-year puzzle Direct measurement:
balloon & satellite borne experiments
1015eV un-reachable by now
Indirect measurements: Ground-based measurements
But there is inconsistency in ground-based measurements.
— Difficulty in composition identification (model dependent , poor measurement, statistics, Observations at different altitudes, low flux…
— Energy scale (Calibration)
Model dependent & LHCf results (QGSJET II?)

7. The VHE g-ray Physics Program
Interstellar magnetic fields affect CRs.
Pulsars
SNRs
Origin of Cosmic Rays
Microquasars
AGNs
GRBs
Cold Dark Matter
cosmological
g-Ray Horizon
Test of the speed of light invariance

8. TeV γRays

9. (Leptonic model) RXJ1713 (Hadronic model)
VHE  astronomy—the first light
(Leptonic model) RXJ (Hadronic model)
Standard candle Crab Nebula
Hadronic model /Leptonic model？
Spectra Energy Distribution
Morphology

10. VHE  ray astronomy success of the Imaging air Cherenkov telescopes IACTs and the bottleneck？
Ferni
~100 VHE  ray sources
Galactic: 60 (after 2009: 3)
extra-galactic: 38 (after 2009: 16)
FOV, duty cycle (10%)
Full duty cycle, full sky survey
Lower threshold, higher sensitivity
CTA: 100 tels, 1km210GeV, 1mCrab
HAWC: 150mx150m, 900 water tanks

11. Possible Solutions:
(1) TeVγray observation has an opportunity of finding CR origin.
Observation ofγat high energy (>30TeV) is crucial, which needs the detectors with high sensitivity and high energy resolution.
All-sky survey forγsource population is necessary, and the detectors have the abilities of full duty cycle, wide FOV and sufficient sensitivity.
(2) PeV CR spectra of individual composition
Bridge between space/balloon borne measurements and ground based UHECR measurements
Ground-based Extensive Air Shower (EAS) detector is the only choice to cover the wide (about 6 orders of) energy range.

12. 4300m a. s. l.：near shower maximum (knee region), low energy threshold
ARGO
AS
4300m a. s. l.：near shower maximum (knee region), low energy threshold
The best high altitude site for cosmic ray observation
(YBJ Cosmic Ray Observatory)
Science，2006, Vol. 314, pp. 439
Anisotropy distribution E >7-8TeV CRs

13. 2. Design of the complex experiment of LHAASO project
4 major components: KM2A, WCDA, and SCDA, WFCTA.
Figure Detector array layout of the LHAASO project
The LHAASO project is proposed to study gamma ray astronomy from 40GeV to 1PeV by
searching for cosmic ray sources using gamma rays above 30TeV,
survey in the whole northern sky for gamma ray sources above 100GeV and
gamma ray source observation using high resolution telescopes
and cosmic ray physics from 5TeV to 1EeV in
energy spectrum for individual composition above 5TeV and energy spectrum and composition above 100PeV.

14. LHAASO-KM2A the highest sensitivity at the highest  ray energy
Discovery of the 1st GCR source
Survey of the northern sky with the highest sensitivity (1%ICrab), exploring the origin of galactic cosmic rays
acceleration and propagation
astroparticle physics
new
Expectation: if HESS sources are in the field of view
LHAASO 10 years
CTA 1 year
LHAASO 1 year
For γ Sources, good SED at UHE (10y)

15. LHAASO-WCDA Full Sky Survey of TeV  Ray Sources (extra-galactic): the most sensitive (2% Icrab) surveying
All the known TeV  ray sources will be observed by LHAASO in one year
Hundreds of TeV  ray sources are expected in 10 years
More sensitive than CTA for extended sources
LHAASO 1 year
LHAASO 10 years
CTA 1yr
Light curve in minute scale for Mrk421 as an IACT can do but with full sky survey and full duty cycle.
Two times better than HAWC for detecting GRBs

16. Study of Cosmic Rays: Energy beyond the Knee Hybrid observations (ARGO-YBJ，KM2A，WCDA，WFCTA and SCDA): the widest energy coverage (5× eV), accurate measurement of composition and energy spectrum through multiple parameters (core, muon, Xmax, etc)
Extending the energy range to EeV by Fluorescence observation (cost free re-configuration)
Transferring the energy scale by WFCTA
Anchoring the energy by ARGO-YBJ

17. Other Physics Goals of LHAASO
Dark Matter g-rays from the sub-halos
LHAASO sensitivity
g-rays from smooth bkg
ARGO sensitivity
E-W width  = 0.43°0.06
Anti-proton/proton ratio
Extra-galactic sources
Galactic sources
CRs blocked by the Moon
Solar activity--forecast magnetic storms

18. 3. Experimental progress of the prototypes
For 4 major components, KM2A, WCDA, and SCDA, WFCTA, the performances and characteristics of their prototypes have been studied or being measured in different steps.
To study the characteristics of 4 kinds of Detector Units by calibrating the candidate PMTs, assembling the detectors and measuring their performances.
To install the responding engineering array and take data, which aims at the absolute time calibrations, confirmation of the capabilities of the electronics and DAQ system, as well as the development of a data analysis package.
To construct a LHAASO complex engineering array (<1% LHAASO scale) at Yangbajing Cosmic Ray Observatory. with 42 EDs, 3 MDs, a prototype WCDA, 2 WFC telescopes and a SCDA prototype array. Coincident with ARGO array, the helpful experiences of complex experiment would be accumulated.

19. Primary study of WCD prototype in IHEP
Fig. Response to muons
Water circulation system
Water attenuation length is more than 17m.
2 R5912 PMTs
A water tank 7m in diameter and 5m in height was constructed at the Institute of High Energy Physics (IHEP), CAS, with a water circulation system to keep the water pure.
A three-fold coincidence in the telescope (3 scintillation detectors ) can identify muons passing through the water tank.

20. ED engineering array at YBJ
The engineering array (consisting of 42 EDs) has been deployed inside the hall of ARGO-YBJ experiment with the same spacing as in the KM2A, fully overlapping with the ARGO-YBJ array. A match between the Engineering array events and the ARGO-YBJ ones in a time window of 2 microsecond is performed based on the event times.
The engineering array have kept taking data smoothly at YBJ. Matched with ARGO data, the results from array data show its performance, such as direction reconstruction. more physical work are in progress.
Fig. An example shower front observed by ARGO-YBJ experiment (blue) and the engineering array (red).

21. 7m 1.2m Muon detectors’ optimization and its prototype at YBJ
Ground
Concrete housing
Plastic
water
tank
2.5 m Pile of dirt
1.2m 7m
The optimization of MD’s prototype benefits from a GEANT4-based simulation package. By restraining the punching-through effects, the simulation optimization gives the sizes of Muon detectors, such as its diameter and height, and the height of the convertor (dirt) on the top of MDs .
2 MD prototypes based on water Cherenkov technique would be completed at YBJ this year.

22. WFCTA prototype on site
Two WFCTA prototype telescopes have been designed and placed near the ARGO-YBJ experimental hall. They have been operating since 2007 with more than 500,000 Cerenkov events acquired in coincidence with ARGO-YBJ experiment.
WFCTA prototype on site 22

23. WFCTA shower at YBJ

24. SCDA Prototypes
A SCDA prototype array with 16 detector units have been developed and deployed inside the ASγ EAS array for hybrid observation with the ASγ experiment.

25. 4. Site preparation and status of proposing
Tibet Site in Yangbajing Valley
A tentative site is located at Yangbajing (4300m a.s.l.), Tibet, China, near the ASγ and ARGO-YBJ experiments.
4360 m

26. Status of Proposing
In Nov. 2010, CCDR (Chinese Committee of Development and Reformation) reviewed all proposals in 7 groups and LHAASO was ranked as No. 1 in the group of HEP&NP
In Jan. 2011, CCDR reviewed 21 candidate projects and LHAASO was selected as one to be supported in next 5 years
The proposal is expected to be approved soon because of its readiness in terms of R/D and site preparation

27. Domestic collaboration:
ARGO collaboration:
APC of IHEP
Tibet Univ.
SW Jiaotong Univ.
Yunnan Univ.
Shandong Univ.
Hebei Normal Univ.
New collaborators
EPC of IHEP
USTC
Tsinghua Univ.
PKU
IAP
CSSAR
NSMC
IMP
Communication Members (potential collaborators):
Shanghai Jiaotong Univ.
Eastern Institute of Science and Technology
Nanking Univ.

28. International collaboration
ARGO collaboration:
Rome II Univ.
Napoli Univ.
Turino Univ.
France IN2P3
expertise in Water Cherenkov technique (Auger experiment)
ASIC (PARISROC) dedicated to PMT readout
Russia Tunka;
…..
Communication Members (future collaborators):
HAWC Coll. …

29. Collaboaration on Microelectronics for LHAASO project
IHEP & LAL
Yan Xiongbo**
Wei Wei **
Wang Zheng **
Chang JinFan **
** IHEP Beijing
Selma Conforti *
Christophe de La Taille *
Gisèle Martin-Chassard *
*OMEGA-LAL Orsay

30. OMEGA/LAL-IHEP collaboration (2008-2011)
Collaboration laid out at Beijing in april 07,2007
Goal : design common chip for PM readout and sharing building blocks
Wei Wei has stayed 6 months in Orsay (feb08-aug08)
PArISROC1 developped for PMm2 (high speed amplifier, Wilkinson ADC and TDC)
Yan Xiongbo stayed one year in Orsay (nov. 08 –oct.09)
He participated to measurements of PARISROC1 in Orsay
He designed blocs of the second version: PARISROC2 (new slow shaper and bandgap)
30/11/2017

31. Design requirement of readout ASIC chips
Using a current available chip (PARISROC2) or design a new chip for both WCDA or KM2A detectors of LHAASO
Specifications:
Number of Input Channels: 3 or 4
Charge Dynamic Range :1P.E.~4000P.E.
Charge Resolution:
Timing Resolution: RMS < 500ps
Processing Period: <1us
Multi-hit Capacity
Output: LVDS
Calibration: Calibration input for all the channels
Monitor: Some key node can be observed
Configuration: JTAG or other readable mode
USTC, Shubin Liu
2011/02/18

32. PARISROC 2 general schematic
Designed by LAL (IHEP people joined the design)
30/11/2017

33. Progress of PARISROC2 chip
Demonstrator realized by the IPNO with 16 x 8-inch Hamamatsu tubes.
Test stand will be setup soon to check performance of PAROSROC2 chips for LHAASO
Necessary modifications of PARISROC2 will be carried out in the next 2 years
30/11/2017

34. Conclusion
LHAASO is proposed to explore the centennial puzzle: origin of high energy cosmic rays. Hundreds of TeV  ray sources are expected. and LHAASO will measure accurately the cosmic ray spectrum from 5TeV up to 1EeV, anchoring and transferring the energy scale of ground-based experiments
An engineering array is being constructed at YBJ for coincident observation with the ARGO-YBJ experiment.

35. for giving LHAASO this opportunity
Thanks to the FCPPL
for giving LHAASO this opportunity