B.Satyanarayana(For INO collaboration)

 Department of High Energy Physics

Tata Institute of Fundamental ResearchHomi Bhabha Road, Colaba, Mumbai, 400 005

E-mail: bsn@tifr.res.in

Proposed detector and data readout system for the

India-based Neutrino Observatory(INO)

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 2

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

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 3

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

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 4

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, BhubaneswarAmit Roy

Nuclear Science Centre, New DelhiJ.B.Singh, M.M.Gupta, V.Bhatnagar

Panjab University, Chandigarh  S.D.Sharma

Himachal Pradesh University, SimlaA.Joshipura, S.Rindani

P.R.L., AhmedabadA.Bhadra,B.Ghosh,A.Mukherjee,S.K.Sarkar

North Bengal UniversityS.UmasankarIIT, Mumbai

S.K.SinghAMU

Scientific Advisors: G.Rajasekaran, Bikash Sinha, Ramnath Cowsik,V.S.Narasimham, H.S.Mani, Amit Roy 

INO Collaboration

41 Experimentalists & Engineers22 Theorists

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 5

Proposed INO detector

Magnetised iron calorimeter

Iron

RP

C

140

laye

rs

• RPC dimension: 3m X 2m

• No of chambers: 11K

• No of channels: 220K

• No of TDC channels: 3K

35KTons

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 6

A passing charged particle induces an avalanche, which develops into a spark. The discharge is quenched when all of the locally ( ) available charge is consumed.

2cm 1.0r

The discharged area recharges slowly through the high-resistivity glass plates.

Before spark After spark

Signal pickup(X)

Signal pickup(Y)

GlassPlates

Graphite

Graphite

Spacer

++++++++++++++++++++

-------------------------++++++ ++++++

---------- -------

RPC principle of operation

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 7

E a c h d i s c h a r g e l o c a l l y d e a d e n s t h e R P C . T h e r e c o v e r y t i m e i s a p p r o x i m a t e l y

l

A

A

lRC

N u m e r i c a l l y t h i s i s ( M K S u n i t s )

s 2)10 x (8.85 x 4 x )10 x ( -1210

A s s u m i n g e a c h d i s c h a r g e d e a d e n s a n a r e a o f , r a t e s o f u p t o c a n b e h a n d l e d w i t h 1 % d e a d t i m e o r l e s s . T h i s i s w e l l b e l o w w h a t i s e x p e c t e d i n o u r a p p l i c a t i o n .

2Hz/m 500

2cm 1.0

+ + + + + + + + + + + + + +

- - - - - - - - - - - - - - - - - - - -

RPC rate capability

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 8

Two 2 mm thick float GlassSeparated by 2 mm spacer

2 mm thick spacer

Glass plates

Graphite coating on the outer surfaces of glass

Signalpickup strips

RPC construction

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 9

A small area RPC prototypeGas inlet

HV terminals

Graphite coat

Gas outlet

Spacer

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 10

P1P2

P3

P4P5

P6

Glass RPC under test

Muon Trigger =654321 PPPPPP

Cosmic muon trigger and timing

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 11

RPC test setup

Cosmic muon telescope

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 12

NIM and CAMAC electronics

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 13

Telescope rate monitoring

100000

120000

140000

160000

180000

200000

220000

240000

260000

280000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Time, Hours

Tele

scop

e pa

ddel

rat

es

P1

P2

P3

P4

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 14

Schematic of gas mixing unit

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 15

Gas mixing unit

Argon

Iso-butane

R134A(Freon)

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 16

Schematic of digital gas bubble counter

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 17

Digital gas bubble counter

Temperature and RH meter

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 18

Typical RPC pulse profiles

Trigger pulse

In streamer mode of operation, pulses are large (>100 mV into 50) and fast (tr < 1ns)

X-Strip

Y-Strip

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 19

Typical RPC efficiency plot

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 20

Typical timing distribution plots

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 21

Typical time response plot

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 22

Typical time resolution plot

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 23

RPC typical charge distributions

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 24

RPC typical mean charge plot

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 25

RPC pulse height Vs timing plot

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 26

RPC typical noise rate plot

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 27

Typical cross-talk plots

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 28

Summary of cross-talk measurements

Gas Mixture Slit Size

(mm)Cross talk (%)

62:8:30 10 6.8

62:8:30 15 6.7

62:8:30 20 6.2

57:8:35 20 6.5

52:8:40 20 5.9

46:8:46 20 6.3

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 29

Gas mixtures’ study plots

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 30

Effect of water vapour in gas

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 31

Effect of water vapour in gas

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 32

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.

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 33

RPC recovery plots

No of hours of gas flow

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 34

New RPC test setup

8020 Sections

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 35

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

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 36

Readout scheme for prototype X-plane RTC Y Final X Trigger TDC Event Scalers

FEE Control Logic Read Data &

Monitor Monitor Scalers CAMAC Controller

LAN

PC (LINUX)

CAMAC

1 2 8 9 10 14

1 2 8 9 10 14

Front End Electronics

Trig & TDC Router

Y-p

lane

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 37

32-channel front-end module 1 2 3 ……………………………………………………………32

Threshold

Mon SI

Mon SO

Addr & Control

Event Trig

Eve SI Eve SO

FPGA

32 ECL Comparators

Trigger 0 Logic (ECL)

&

Timing signal

Trigger 1 M fold Logic

( CPLD )

Level Translator & Wave shaper (32+8)

SHIFT REGISTER ( 48 bit )

Board ID (SW8)

Monitor

MUX unit ( 40 : 1 )

Module Selection

LV

DS

EVE (SW4) MON(SW4)

Counter

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 38

Prototype detector trigger logic

Front End Electronics X-Plane Y-Plane Level-0

Level 1 S1….S8 S1…S8 S1…S8

1F,2F……4F 1F,2F……4F 1F,2F……4F 1F,2F……4F (LVDS interface)

Level-2 ( Back end )

F1(14)…………..F4(14) F1(14)…………..F4(14) (

OR

L1P1

(mF)

L14P1

(mF) L14P2

(mF) L1P2

(mF)

P1 (m x n fold)

P2 (m x n fold)

Final Trigger

S1=1+9+17+25 S2=2+10+18+26 ………. S8=8+16+24+32

Trigger & TDC signals Router

Trigger & TDC signals Router

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 39

Readout scheme for final detectorThe keywords are channel count and fast timing

B.Satyanarayana, TIFR, Mumbai NSNI-2004, Kalpakkam, February 17-20, 2004 40

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