1. A LARGE ATMOSPHERIC NEUTRINO DETECTOR USING RESISTIVE PLATE CHAMBERS
Naba K Mondal
Tata Institute of Fundamental Research
Mumbai, India
RPC2005, Korea University, Seoul, Oct, 2005

2. Celebrating 40 years of atmospheric neutrino detection
Physics Letters 18, (1965) 196, dated 15th Aug 1965
Atmospheric neutrino detector
at Kolar Gold Field –1965
RPC2005, Korea University, Seoul, Oct 10-12, 2005
PRL 15, (1965), 429, dated 30th Aug. 1965

3. India-based Neutrino Observatory initiative
Goal: A large mass detector with charge identification capability
Two phase approach:
R & D and Construction
Phase I
Physics studies,
Detector R & D,
Site survey,
Human resource development
Phase II
Construction of the detector
Operation of the Detector
Phase I
Physics with Atmospheric Neutrinos
Phase II
Physics with Neutrino beam from
a factory
RPC2005, Korea University, Seoul, Oct 10-12, 2005

4. Physics using atmospheric neutrinos during Phase I
Reconfirm atmospheric neutrino oscillation
Improved measurement of oscillation parameters
Search for potential matter effect in neutrino oscillation
Determining the sign of Dm223 using matter effect
Discrimination between nm  nt and nm  ns oscillation
Probing CP and CPT violation
Constraining long range leptonic forces
Ultra high energy neutrinos and muons
RPC2005, Korea University, Seoul, Oct 10-12, 2005

5. Physics with Neutrino beam from NUFACT – Phase II
Determination of q13
Sign of Dm223
Probing CP violation in leptonic sector
Matter effect in nm  nt oscillation
RPC2005, Korea University, Seoul, Oct 10-12, 2005

6. Disappearance of Vs. L/E
The disappearance probability can be measured with a single detector and two equal sources:
= P(nm  nm; L/E)
N up(L/E)
N down(L’/E)
= 1 - sin2 (2Q) sin2 (1.27 Dm2 L/E)
RPC2005, Korea University, Seoul, Oct 10-12, 2005

7. Matter Effect & Sign of D31 from event rate
RPC2005, Korea University, Seoul, Oct 10-12, 2005

8. RPC2005, Korea University, Seoul, Oct 10-12, 2005
nm nt vs nm ns
nmnt events will give rise to excess of muon less events. There will be excess of upgoing muonless events.
RPC2005, Korea University, Seoul, Oct 10-12, 2005

9. RPC2005, Korea University, Seoul, Oct 10-12, 2005
CPT Violation
The expression for survival probability for the case of CPTV 2-flavour oscillations
and
RPC2005, Korea University, Seoul, Oct 10-12, 2005

10. Choice of Neutrino Source and Detector
Need to cover a large L/E range
Large L range
Large En Range
Use Atmospheric neutrinos as source
Detector Choice
Should have large target mass ( kT)
Good tracking and Energy resolution ( tracking calorimeter)
Good directionality ( <= 1 nsec time resolution )
Charge identification
Ease of construction
Modularity
Complimentarity with other existing and proposed detectors
Use magnetised iron as target mass and RPC as active detector medium
RPC2005, Korea University, Seoul, Oct 10-12, 2005

11. RPC2005, Korea University, Seoul, Oct 10-12, 2005
INO Detector Concept
RPC2005, Korea University, Seoul, Oct 10-12, 2005

12. RPC2005, Korea University, Seoul, Oct 10-12, 2005
The Magnet
RPC2005, Korea University, Seoul, Oct 10-12, 2005

13. ICAL Detector Specifications
No of modules 3
Module dimension
16 m X 16 m X 12 m
Detector dimension
48 m X 16 m X 12 m
No of layers
140
Iron plate thickness
6 cm
Gap for RPC trays
2.5 cm
Magnetic field
1.3 Tesla
RPC unit dimension
2 m X 2 m
Readout strip width
3 cm
No. of RPCs/Road/Layer 8
No. of Roads/Layer/Module
No. of RPC units/Layer
192
Total no of RPC units
27000
No of Electronic channels
3.6 X 106
RPC2005, Korea University, Seoul, Oct 10-12, 2005

14. RPC2005, Korea University, Seoul, Oct 10-12, 2005
RPC R & D
Built RPCs of different sizes
30 cm X 30 cm
120 cm X 90 cm
RPC2005, Korea University, Seoul, Oct 10-12, 2005

15. RPC Efficiencies and Timing
RPC working in Streamer mode
RPC2005, Korea University, Seoul, Oct 10-12, 2005

16. RPC2005, Korea University, Seoul, Oct 10-12, 2005
RPC in Avalanche mode
CMS bakelite RPC
73 cm X 42.5 cm
120 cm X 90 cm Glass RPC
Built at TIFR
CMS RPC on test stand
RPC2005, Korea University, Seoul, Oct 10-12, 2005

17. Performance in Avalanche mode
Efficiency plots of RPCs in Avalanche mode
Noise Rates of RPCs operating in Avalanche mode
RPC2005, Korea University, Seoul, Oct 10-12, 2005

18. RPC2005, Korea University, Seoul, Oct 10-12, 2005
Detector Simulation
Used NUANCE Neutrino Event Generator
Generate atmospheric neutrino events inside INO detector
Used Atmospheric Neutrino Flux of Honda et. al.
GEANT detector simulation package
Simulate the detector response for the neutrino event
Generated 5 years of simulated data equivalent to 5 years of running the experiment.
Analysed oscillation data at two levels
Using NUANCE output and kinematic resolution function
Using full detector simulation
Obtained preliminary results so far. Detailed simulation is underway.
RPC2005, Korea University, Seoul, Oct 10-12, 2005

19. RPC2005, Korea University, Seoul, Oct 10-12, 2005
Results using NUANCE n m
RPC2005, Korea University, Seoul, Oct 10-12, 2005

20. Location of the Underground Laboratory
Studies were performed on two potential sites.
Pykara Ultimate Stage Hydro Electric Project (PUSHEP) at Masinagudi, South India
Rammam Hydro Electric Project Site at Darjeeling District in West Bengal
INO Site Selection Committee after thorough evaluation have now recommended PUSHEP in South India as the preferred site for the underground lab.
RPC2005, Korea University, Seoul, Oct 10-12, 2005

21. RPC2005, Korea University, Seoul, Oct 10-12, 2005
Summary
A large magnetised detector of kton is needed to achieve some of the very exciting physics goals using atmospheric neutrinos.
A case for such a detector was highlighted earlier by the Monolith Collaboration.
Physics case for such a detector is strong as evident from recent publications.
It will complement the existing and planned water cherenkov detectors.
Can be used as a far detector during neutrino factory era.
We have started a very active R & D work towards building such a detector.
Need participation from international neutrino community.
RPC2005, Korea University, Seoul, Oct 10-12, 2005