INO Collaboration

1. INO Collaboration B.S.Acharya, Sudeshna Banerjee, P.N.Bhat, S.R.Dugad, P.Ghosh, K.S.Gothe, S.K.Gupta, S.D.Kalmani, N. Krishnan, N. K Mondal, B.K.Nagesh , P.Nagaraj, Biswajit Paul, A.K.Ray, Probir Roy, B.Satyanarayana, S.Upadhaya, P.Verma Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai V.M.Datar, M.S.Bhatia, S.K.Kataria Bhabha Atomic Research Centre, Mumbai P. Bhattacharya, S.Bhattacharya, S. Chattopadhyay, A.Ghoshal, A.Goswami K. Kar, D.Majumdar, P.B.Pal, S. Saha, M. Sharan, S.Sarkar, S.Sen Saha Institute of Nuclear Physics, Kolkata S. Chattopadhyay, M.R.Datta Mazumdar, P.Ghosh, G.S.N.Murthy, T.Nayak, Y.P.Viyogi Variable Energy Cyclotron Centre, Kolkata  Amitava Raychaudhuri Calcutta University, Kolkata M.V.N.Murthy, D.Indumathi Institute of Mathematical Sciences, Chennai A. Datta, R.Gandhi, S.Goswami, S. Rakshit, P.Mehta Harish Chandra Research Institute, Allahabad S.C.Phatak, D.P.Mahapatra IOP, Bhubaneswar Amit Roy Nuclear Science Centre, New Delhi J.B.Singh, M.M.Gupta, V.Bhatnagar Panjab University, Chandigarh   S.D.Sharma Himachal Pradesh University, Simla A.Joshipura, S.Rindani P.R.L., Ahmedabad A.Bhadra,B.Ghosh,A.Mukherjee,S.K.Sarkar North Bengal University S.Umasankar IIT, Mumbai S.K.Singh AMU Scientific Advisors: G.Rajasekaran, Bikash Sinha, Ramnath Cowsik,V.S.Narasimham, H.S.Mani, Amit Roy 41 Experimentalists & Engineers 22 Theorists

2. Proposed INO detector Magnetised iron calorimeter • RPC dimension: 3m X 2m • No of chambers: 11K • No of channels: 220K • No of TDC channels: 3K (2 Tesla solenoid) Iron 140 layers RPC 35KTons

3. RPC principle of operation

4. RPC construction

5. A small area RPC prototype Gas inlet Graphite coat Spacer Gas outlet HV terminals

6. Cosmic muon trigger and timing

7. RPC test setup 8020 Sections

8. Schematic of gas mixing unit

9. Typical RPC efficiency plot

10. Typical timing distribution plots

11. Typical time response plot

12. RPC timing resolution plot

13. RPC typical charge distributions

14. RPC typical mean charge plot

15. RPC typical noise rate plot

16. Gas mixtures’ study plots

17. INO prototype detector • Detector and signal specifications • Detector dimensions: 1m X 1m X 1m • 14 layers of RPCs with 6cm iron plates interleaved. • Two signal planes orthogonal to each other and each having 32 pick-up strips • Total channels = 32 X 14 X 2 = 896 • Pulse height = 100 to 300mV; Rise time = < 1 ns • Pulse width = ~50ns; Rate ~ 1KHz • Trigger information • Expected trigger rate is few Hz • Required Trigger logic is m X n fold, where • m = 1 to 4; no. of consecutive channels in a layer • n = 5 to 1; no. of consecutive layers with m fold in each layer • ie m x n = (1 x 5) OR (2 x 4) OR (3 x 3) OR (4 x 2) • Information to be recorded on a trigger • Absolute arrival time of the trigger • Track identification (XYZ points in RPC layers) • Direction of track ( TDC information) • Miscellaneous information and calibration data • Monitoring health of the detector

18. Current status • Gas mixing and distribution system developed • Production of small area (1 ft2) RPCs successful • Studied efficiency and timing resolution of RPCs • Detailed studies on effect of water vapour in gas and long term stability of chambers in progress • Electronics for prototype detector electronics finalised • Production of circuit boards and other components in progress

19. Future plan • Production of prototype detector chambers (4 ft X 3 ft) • Study of pickup strip materials and geometries • To study avalanche mode of operation, improving timing resolution • Continuation of work on gas mixtures including SF6 • Design of electronics, trigger and DAQ schemes for the final detector • Cooperative VLSI and ASIC development programmes for electronics being explored