Experiences with RPC Detectors in Iran and their Potential Applications Tarbiat Modares University...

Experiences with RPC Detectors in Iran and their Potential Applications

Tarbiat Modares University

Ahmad Moshaii

A. Moshaii, IPM international school and workshop on Particle Physics (IPP12)

IPM international school and workshop on Particle Physics (IPP12): Neutrino

Physics and AstrophysicsSchool of Physics, IPM, Tehran, Iran

September 26-October 1, 2012(5-10 Mehr, 1391)

(TMU)Tarbiat Modares University, Tehran, Iran

Introducing Resistive Plate Chamber (RPC) detector

Simulation of RPC performance

Experimental activities with RPC detector

Potential Applications of RPC detector

Outlines

A. Moshaii, First IPM Meeting on LHC Physics, Isfahan 20-24 April, 2009A. Moshaii, IPM international school and workshop on Particle Physics (IPP12)

HIGH RESISTIVITY ELECTRODE

GAS GAP

GRAPHITE COATING

INSULATOR (Myler)

READOUT STRIPS Y

READOUT STRIPS X

HV

GNDSPACER

Introducing Resistive Plate Chamber (RPC) Detector

Transverse slice through RPC:

Resistivity of the plates should be more than 1010 .cm


Two 2 mm thick float glassesseparated by 2 mm spacers

2 mm thick spacer

Glass plates

Graphite coating on the outer surfaces of glass

Signal pickup strips for X-Y readout

An Introduction to RPC

3D View:


An Introduction to RPC

Layout of CMS RPCs:


High Resistive Plates Gas Gap

Ionization Beam

+ -

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

extE

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

Principles of Operation



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

extE

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


+

_



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

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

locE

t

t eQQ

)0()(

extE



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

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

extE

TimeRelaxation


1s for Glass

10ms for Bakelite



electric field

electric field

electric field

extEA. Moshaii, IPM international school and workshop on Particle Physics (IPP12)

RPC Operation Regions

I

I. RecombinationII. IonizationIII. ProportionalIV. Limited ProportionalV. Geiger-MullerVI. Discharge

II III IV V VI

V1 V3V2 V5V4 V6Applied Voltage

Pu

lse

Am

plit

ude

(log

sca

le)

Modes of Operation


RPC Streamer Mode

RPC Avalanche Mode

Breakdown Point

I


II III IV V VI


Pu

lse

Am

plit

ude

(log

sca

le)

Modes of Operation

A. Moshaii, First IPM Meeting on LHC Physics, Isfahan 20-24 April, 2009

Space Charge Becomes Important

I


II III IV V VI


Pu

lse

Am

plit

ude

(log

sca

le)

Modes of Operation


Space Charge Effect:

The electrons are collected relatively quickly (ns) at the anode leaving behind the positive ions that move much more slowly. The positive ions form a space charge that appreciably distort the electric field and the process of electron avalanche inside the gap.

Modes of Operation

Space charge is the main factor restricting the avalanche growth


Simulation of RPC performance

Based on Transport Equations:

Stxntxntxnxt

txneee

e

),(),(),(

),(

Stxnt

txne

),(

),(

Stxnt

txne

),(

),(

ne is the number density of electrons

n+ and n- are the number densities of positive and negative ions

S is photon contribution for the electrons avalanche

Townsend Coefficient : Attachment Coefficient: Drift Velocity :

Dynamic Simulation

x

txtxE

),(

),(g

tx

x

tx

),(),(

2

2

),(),(),(),( 0 txntxntxnetx e

Dynamic Simulation

Based on Transport Equations:

),(),(),(),(

txntxntxnxt

txneee

e

),(),(

txnt

txne

),(),(

txnt

txne

Space charge field:


Simulation Input:

MAGBOLTZ (Townsend Coefficient, Attachment Coefficient, Drift Velocity) Steve Biagi

Dynamic Simulation


Dynamic Simulation

Space Charge:

xd

Anode

Cathode

x

R

x

d

xPREd

xEd

Origin

r

xdRxx

xxEI

mxxdiscx

2201 12


r

Gap

Anode

Cathode

P

Dynamic Simulation

Space Charge:

d

d

d

x

x

dtotx IIIIEE

2

11

0

1

0

1chargeSpace

x


= Initial condition= Boundary condition = Interior point

Finite Difference Method (Lax Numerical Scheme):

Time

Distance

Dynamic Simulation


Dynamic Simulation

1) Avalanche Mode

2) Avalanche to Streamer Transition

3) Streamer Mode

R. Cardarelli, V. Makeev, R. Santonico,Nucl. Instr. and Meth. A382 (1996) 470


Dynamic Simulation

Initial Conditions:

1) Avalanche Mode

sStepsTime

kVHV

SFHCiHFC

10

6104242

101

10

3.0/3/7.96//


Monte Carlo Simulation & Results

Charge Spectrum:

3.0/3/7.96

// 6104242 SFHCiHFC

Dynamic Simulation

Spatiotemporal Growth:

1) Avalanche Mode

approximate analytical solution.

Compared to:

P. Fonte, IEEE Trans. Nucl. Science, 43:2135–2140, 1996


Dynamic Simulation

1) Avalanche Mode


Dynamic Simulation

Space Charge Field:

1) Avalanche Mode


Dynamic Simulation

1) Avalanche Mode (5 Clusters)

Initial Conditions:


Dynamic Simulation





Total Electric Field:

Dynamic Simulation

Still not enough to distort the applied field



Dynamic Simulation



Dynamic Simulation

sStepsTime

kVHV

SFHCiHFC

10

6104242

101

04.11

3.0/3/7.96//




Dynamic Simulation

Space Charge Field:

Space Charge is becoming comparable to the applied field


3) Streamer Mode

Dynamic Simulation


sStepsTime

kVHV

SFHCiHFC

10

6104242

101

42.11

3.0/3/7.96//


Dynamic Simulation

3) Streamer Mode

Pre-Pulse

Streamer Pulse


Main Simulation outputs:

Monte Carlo Avalanche Simulation

Space Charge

Avalanche Mode

Saturated Avalanche Mode

Streamer Formation

Dynamic Simulation


Window glass HIGH RESISTIVITY ELECTRODE

Window glass

Experimental activities with RPC detector

GAS GAP

Silicone glue

38

cm45 cm

GRAPHITE COATING

Graphite coating

20 kΩ

HV connection

INSULATOR

Mylar sheet

READOUT STRIPS X

READOUT STRIPS Y

Resistor R=50 Ω

Faraday cage

Aluminum foil

Gas Mixing System Diagram

Construction of the Gas Mixing System for RPCs

150

cm

50 cm

Construction of the Gas Mixing System for RPCs

2- States Valve: To allow the gas flow

Regulator: To adjust the input gas pressure

Pressure Gauge: to show the input gas pressureTemperature Gauge: to show the input gas temperatureMixer: to mix the used gases (Ar/CO2)Low Range Flow Meter( 0-20 L/H)3-States valve: To select the output gas mixtureGas Mixture OutputsBubbler: To have a uniform flow in RPCPressure Gauge: to show the mixed gas pressure

Gas Connector

Glass RPC

HV Supply

ground

+HV

-HV

Digital oscilloscop

e

signal

Gas inputGas output

Gas mixin

g syste

mAr

50 Ω

CO2bubbler

Experimental Setup

Experimental Study of the RPCs Time Resolution

1/16/2010TMU44

Glass RPC

HV Supply

ground

+HV

-HV

Digital oscilloscop

e

signal

Gas inputGas output

Gas mixin

g syste

mAr

50 Ω

CO2bubbler

Charged particles

Rise Time: Electron Component Fall Time: Ion Component

Experimental Study of the RPCs Time Resolution

1/16/2010TMU45

2-mm glass RPC2-mm Gas GapHV= 3.5 kvAr

-4 16 36 56 76 96 1160

1

2

3

4 mean=49.6365𝜎=16.7244

time resolution=49.6∓16.7

interval time(ns)

coun

ts

2-mm glass RPC2-mm gas gapHV=3.5 kv

pure Ar

1-mm glass RPC1-mm Gas GapHV= 4, 5 kvAr/CO2 50/50

HV= 4 kv

HV= 5 kv

-30 -10 10 30 50 70 90 110 130 1500

0.5

1

1.5

2

2.5

3

3.5

4

4.5 mean=55.3354𝜎=28.2876

time resolution=55.3∓28.2 ns

Interval time(ns)

Co

un

ts

Ar/CO2 50/50

-30 -10 10 30 50 70 90 110 130 150 1700

0.5

1

1.5

2

2.5

3

3.5 mean=59.5𝜎=29.43

time resolution=59.5∓29.4

Interval time(ns)

Co

un

ts

Ar/CO2 50/50

HV= 4 kv HV= 5 kv

2-mm glass RPC1-mm Gas GapHV= 2.5, 3, 3.5, 4 kvAr/CO2 50/50

HV= 2.5 kv

HV= 3.5 kvHV= 4 kv

HV= 3 kv

-5 0 5 10 15 20 25 30 35 400

0.5

1

1.5

2

2.5

3

3.5

4

time resolution=16.8∓5.7 nsAr/CO2 50/50

Interval time(ns)

Coun

ts

mean=16.8564𝜎=5.782252 ns

-5 0 5 10 15 20 25 30 35 40 450

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Interval time(ns)

Co

un

ts

Ar/CO2 50/50mean=17.896 ns𝜎=4.9722 ns


-3 2 7 12 17 22 27 320

1

2

3

4

5

6

7 mean=14.6975 ns𝜎=5.0743 ns

Interval time(ns)

Co

un

ts


Ar/CO2 50/50

-5 0 5 10 15 20 25 300

1

2

3

4

5

6 mean=15.2458 ns𝜎=3.9580 ns


Interval time(ns)

Co

un

ts

Ar/CO2 50/50

HV= 2.5 kv

HV= 4 kv HV= 3.5 kv

HV= 3 kv

2-mm glass RPC1-mm Gas GapHV= 2.5, 3, 3.5, 4 kvAr/CO2 70/30

HV= 2.5 kv

HV= 4 kv HV= 3.5 kv

HV= 3 kv

-5 0 5 10 15 20 25 30 350

0.5

1

1.5

2

2.5

3

3.5

4 mean=15.68 ns𝜎=4.30 ns

time ∓resolution=15.64.3 ns

Interval time(ns)

Cou

nts

Ar/CO2 70/30

-5 0 5 10 15 20 250

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5 mean=12.16 ns𝜎=3.58 ns

Interval time(ns)

time resolution=12.6∓3.5 nsAr/CO2 70/30

Coun

ts

-5 0 5 10 15 20 25 300

0.5

1

1.5

2

2.5

3

3.5

4

4.5 mean=14.765𝜎=4.12

Interval time(ns)

Co

un

ts

time resolution=14.6∓4.1Ar/CO2 70/30

-5 0 5 10 15 20 25 300

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Interval time(ns)

Co

un

ts

Ar/CO2 70/30 mean=16.165 ns𝜎=3.9855 nstime resolution=16.1∓3.9 ns

HV= 2.5 kv

HV= 3.5 kvHV= 4 kv

HV= 3 kv

2-mm glass RPC1-mm Gas GapHV= 2, 3, 3.5 kvAr/CO2 85/15

HV=2 KVHV=3 KVHV=3.5 KV

-12 -7 -2 3 8 13 18 23 28 33 380

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Interval time(ns)

Co

un

ts

mean=22.72 ns𝜎=3.7373 nsAr/CO2 85/15


-7 -2 3 8 13 18 23 28 330

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5 mean=16.915𝜎=3.561


Interval time(ns)

Co

un

ts

Ar/CO2 85/15

-13 -8 -3 2 7 12 17 22 27 320

1

2

3

4

5

6

7

8 mean=20.022𝜎=2.54

time resolution=20∓2.5 ns

Interval time(ns)

Co

un

ts

Ar/CO2 85/15

HV=2 kvHV=3 kv

HV=3.5 kv

2-mm glass RPC1-mm Gas GapEntries: 200HV= 3 kvAr/CO2 50/50

-5 0 5 10 15 20 250

5

10

15

20

25

30

35

40

45

50 mean=11.257𝜎=3.5848Ar/CO2 50/50


interval time(ns)

entries=200

Coun

ts

Applications:

CERN as a trigger detector Cosmic Ray Detection TOF Measurements PET

RPC Applications

Importance:

Economically Efficient High Efficiency Simple Configuration Good Time Resolution


CMS Forward RPCs

Disk RE4/1 RE4/2 RE4/3

No. of Chambers 18*2 36*2 36*2

Four stations in each endcap

Three rings in each station

Disk RE3/1 RE2/1 RE1/1

No. of Chambers 18*2 18*2 36*2


Conclusion

• All works are going to schedule and progressing well

Thanks for your attentions

And thanks to all colleagues and students collaborating in the works:

Pezeshkian, Doroud, Khosravi, Eskandari, Radkhorami, Hosseini, and Jamali


• Preparing a dedicated gas mixing system for RPCs equipped with digital MFCs

• The system now is equipped by two different gases and is ready to use for test of RPCs

GAS MIXING SYSTEM


Experimental activities at CERN (ISR lab)Construction of a prototype RE1/1 RPC in collaboration with Korean colleagues


Production of 4 prototypes Front End Board (FEB) for CMS RPCs


FEB production at IPMThe board has about 250 electronics components


Experiences with RPC Detectors in Iran and their Potential Applications Tarbiat Modares University...

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