B.Satyanarayana (For INO collaboration) Department of High Energy Physics Tata Institute of...

B.Satyanarayana(For INO collaboration)

Department of High Energy Physics

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

E-mail: [email protected]

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


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.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


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


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


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


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


A small area RPC prototypeGas inlet

HV terminals

Graphite coat

Gas outlet

Spacer


P1P2

P3

P4P5

P6

Glass RPC under test

Muon Trigger =654321 PPPPPP

Cosmic muon trigger and timing


RPC test setup

Cosmic muon telescope


NIM and CAMAC electronics


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


Schematic of gas mixing unit


Gas mixing unit

Argon

Iso-butane

R134A(Freon)


Schematic of digital gas bubble counter


Digital gas bubble counter

Temperature and RH meter


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


Typical RPC efficiency plot


Typical timing distribution plots


Typical time response plot


Typical time resolution plot


RPC typical charge distributions


RPC typical mean charge plot


RPC pulse height Vs timing plot


RPC typical noise rate plot


Typical cross-talk plots


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


Gas mixtures’ study plots


Effect of water vapour in gas


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.


RPC recovery plots

No of hours of gas flow


New RPC test setup

8020 Sections


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


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


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


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


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


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

B.Satyanarayana (For INO collaboration) Department of High Energy Physics Tata Institute of...

Documents

Transcript of B.Satyanarayana (For INO collaboration) Department of High Energy Physics Tata Institute of...