1. B.Satyanarayana (For INO collaboration) Department of High Energy Physics Tata Institute of Fundamental Research Homi Bhabha Road, Colaba, Mumbai, 400 005 E-mail: bsn@tifr.res.inbsn@tifr.res.in Proposed detector and data readout system for the India-based Neutrino Observatory(INO)

2. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 20042 Plan of the talk Introduction Proposed detector RPC basics RPC test stand Gas mixing and distribution system RPC R & D results Electronics for the prototype detector; Thoughts for the final detector Status and future plan

3. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 20043 What and Why Neutrinos? Neutrinos are one of the fundamental particles of matter. Electrically neutral and were initially thought to be mass-less. Three types or flavors of neutrinos known. Recent evidence indicates that neutrinos have mass and also experience mixing among these flavors. Neutrino oscillations can explain the discrepancy between theory and observations about its flux. Neutrino mass can also be indirectly estimated by detecting its eventual oscillations. Non-zero mass for neutrino has profound implications on fields as varied as nuclear physics, particle physics, astrophysics and cosmology. Pioneering experiments at the KGF underground laboratories

4. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 20044 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 INO Collaboration 41 Experimentalists & Engineers 22 Theorists

5. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 20045 Proposed INO detector Magnetised iron calorimeter Iron RPC 140 layers RPC dimension: 3m X 2m No of chambers: 11K No of channels: 220K No of TDC channels: 3K 35KTons

6. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 20046 RPC principle of operation

7. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 20047 RPC rate capability

8. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 20048 RPC construction

9. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 20049 A small area RPC prototype Gas inlet HV terminals Graphite coat Gas outlet Spacer

10. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200410 Cosmic muon trigger and timing

11. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200411 RPC test setup Cosmic muon telescope

12. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200412 NIM and CAMAC electronics

13. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200413 Telescope rate monitoring

14. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200414 Schematic of gas mixing unit

15. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200415 Gas mixing unit Argon Iso-butane R134A(Freon)

16. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200416 Schematic of digital gas bubble counter

17. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200417 Digital gas bubble counter Temperature and RH meter

18. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200418 Typical RPC pulse profiles Trigger pulse In streamer mode of operation, pulses are large (>100 mV into 50  ) and fast (t r < 1ns) X-Strip Y-Strip

19. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200419 Typical RPC efficiency plot

20. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200420 Typical timing distribution plots

21. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200421 Typical time response plot

22. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200422 Typical time resolution plot

23. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200423 RPC typical charge distributions

24. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200424 RPC typical mean charge plot

25. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200425 RPC pulse height Vs timing plot

26. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200426 RPC typical noise rate plot

27. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200427 Typical cross-talk plots

28. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200428 Summary of cross-talk measurements Gas MixtureSlit Size (mm) Cross talk (%) 62:8:30106.8 62:8:30156.7 62:8:30206.2 57:8:35206.5 52:8:40205.9 46:8:46206.3

29. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200429 Gas mixtures’ study plots

30. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200430 Effect of water vapour in gas

31. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200431 Effect of water vapour in gas

32. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200432 Recovering a damaged RPC Purging with pure Argon at high flow rate. Bubbling pure Argon through pure ethyl alcohol. Bubbling pure Argon through 25% Ammonia solution for 24 hours without electric field. Recovers efficiency and brings down noise rate. Detail studies underway.

33. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200433 RPC recovery plots No of hours of gas flow

34. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200434 New RPC test setup 8020 Sections

35. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200435 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

36. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200436 Readout scheme for prototype

37. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200437 32-channel front-end module

38. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200438 Prototype detector trigger logic

39. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200439 Readout scheme for final detector The keywords are channel count and fast timing

40. B.Satyanarayana, TIFR, MumbaiNSNI-2004, Kalpakkam, February 17-20, 200440 Current status and future plan Production and study of small area RPCs successful Detailed study of effect of water vapour in gas Repeatability of results and long term stability of RPC Study of pickup strip materials and geometries Production of prototype chambers (4 ft X 3 ft) Gas mixing and distribution system for the prototype detector Prototype electronics finalised Production of circuit boards and other components in progress Initial thoughts given on final electronics and DAQ schemes Cooperative VLSI and ASIC development programmes explored