General layout of the barrel detectorGeneral layout of the barrel detector

RB4 … … 120 chambers

RB3 … … 120 chambers

RB2 … … 120 chambers

RB1 … … 120 chambers

One barrel sector … … … … … ......60 sectors

General layout of the forward detectorGeneral layout of the forward detector

RPC in avalanches… a simple model RPC in avalanches… a simple model

s

d

qs

+

-

-

n 0ve

qe

Qe < qe >= kηd

< Qe (d)> = qeln0

kηd

λη+ λ

eηd

- k= (εr d/s)/( εr d/s +2) - qel is the electron charge- no is the average size of the primary cluster- λ is the cluster density in the gas mixture- εr is the relative dielectric constant- d is the gap width- s is the electrode thickness

- k= (εr d/s)/( εr d/s +2) - qel is the electron charge- no is the average size of the primary cluster- λ is the cluster density in the gas mixture- εr is the relative dielectric constant- d is the gap width- s is the electrode thickness

SimulationSimulation

M avalanche fluctuation

Double gap conceptDouble gap concept

The double gap detector is made out by two single gaps. Between them a planeof readout strips is located.

The double gap detector is made out by two single gaps. Between them a planeof readout strips is located.

A foil of Cupper is draped around the sandwich. It ensure the reference for the signal transmission along the strip and it is the ground of high voltage ad low voltage

A foil of Cupper is draped around the sandwich. It ensure the reference for the signal transmission along the strip and it is the ground of high voltage ad low voltage

CU

-9 kV

Double gap CMS chamberDouble gap CMS chamber

A barrel chamber is made with 4 gapsA barrel chamber is made with 4 gaps

Termination resistors

Cupper foil(ground) wrappedaround the gaps

Z axisConnection to FE

G. Iaselli

- HV

- HV

- HV

- HV

a) b)

The double gap designThe double gap design

Double gap geometryimproves the efficiency andallows safer operation athigher threshold. Also thetime resolution improves.

Double gap geometryimproves the efficiency andallows safer operation athigher threshold. Also thetime resolution improves.

Basic parameters Bakelite thickness 2 mmBakelite bulk resistivity 1-2 .1010 Ω cmGap width 2 mmGas mixtures 95% C2H2F4,5% i-C2H10

Operating High Voltage 8.5 - 9.0 kV

# Gaps 2

Basic parameters Bakelite thickness 2 mmBakelite bulk resistivity 1-2 .1010 Ω cmGap width 2 mmGas mixtures 95% C2H2F4,5% i-C2H10

Operating High Voltage 8.5 - 9.0 kV

# Gaps 2

Basic parametersBasic parameters

Basic parametersBakelite thickness 2 mmBakelite bulk resistivity 2-3 .1010 Ω cmGap width 2 mmGas mixtures 97% C2H2F4, 3% i-C2H10

Operating High Voltage 8.5 - 9.0 kV# Gaps 2

Basic parametersBakelite thickness 2 mmBakelite bulk resistivity 2-3 .1010 Ω cmGap width 2 mmGas mixtures 97% C2H2F4, 3% i-C2H10

Operating High Voltage 8.5 - 9.0 kV# Gaps 2

In most part of the In most part of the muon muon system the value of the dose system the value of the doseintegrated in 10-years is below 1 integrated in 10-years is below 1 GyGy..

A large double gap RPC (A large double gap RPC (ρ =2 10 ρ =2 10 1111) has been irradiated with 11) has been irradiated with 11 mCi mCi of ofγ γ source ( source ( 6060Co ). The performance has been monitored continuously toCo ). The performance has been monitored continuously tospot possibly aging effects.spot possibly aging effects.

Absorbed dose 1.6Gy

Irradiation testsIrradiation tests

Currents and rateCurrents and RateCurrents and Rate

Currents and single rates measured by the chamber under irradiation with sourceCurrents and single rates measured by the chamber under irradiation with sourceopen and closed. The applied voltages have been corrected for pressure andopen and closed. The applied voltages have been corrected for pressure andtemperaturetemperature..

Efficiency and cluster sizeEfficiency and Cluster sizeEfficiency and Cluster size

Efficiencies of the chamber underEfficiencies of the chamber underirradiation with source open andirradiation with source open andclosed.closed.

Average number of fired stripsAverage number of fired stripsclosed to the one associated to theclosed to the one associated to theextrapolated trackextrapolated track..

BARI Gamma Irradiation FacilityThe Gamma Irradiation Facility

at X5 (CERN)The Gamma Irradiation Facility

at X5 (CERN)

155 cm

γ

Beamµ

RPC

20 Ci 137Cs source

Absorbed dose duringthe test: ~23 Gy

Total charge accumulated 525 C

Total charge accumulated 525 C

Total irradiation time 7x 106 s

Total irradiation time 7x 106 s

Irradiation tests are continuing at GIF with a lowresistivity chamber (ρ =2 10 10)

Irradiation tests are continuing at GIF with a lowresistivity chamber ((ρ =2 10 ρ =2 10 1010))

R&D BarrelR&D Barrel

• A full size RB2 chamber tested at GIF during summer-autumn 1999

• Results are very satisfactory

• A full size RB2 chamber tested at GIF during summer-autumn 1999

• Results are very satisfactory

Single gap mode

ρ=1011

R&D ForwardR&D Forward

Extensive R&D during 1999

• A full scale RE2/2 chamber built in Korea was tested at GIF

• A small prototype built in China was also tested at GIF

Extensive R&D during 1999

• A full scale RE2/2 chamber built in Korea was tested at GIF

• A small prototype built in China was also tested at GIF

RE2/2

)R(R

offon

γNSHV

−=

Sensitivity at Bari irradiation facilitySensitivity at Bari irradiation facility

1 double gap RPC (ρ = 2 • 1011Ωcm) 1.3 x 1.2 m2

Gas mixture: 95% C2H2F4 and 5% i-C4H10

No sensible variation withirradiation time is observed

15 mCi of 60Co

φγ ≈ 10 4 cm-2 s -1

Sensitivity for a RB1 CMSSensitivity for a RB1 CMS

RPC area20 x 20 cm2

RPC area250 x 250 cm2

I gap 0.9 10-2 1.21 10-2

II gap 0.79 10-2 1.16 10-2

Double gap 1.51 10-2 2.12 10-2

The RPC hit rate in the CMS RB1 to γ will be about 5 Hz/cm2

CMS Muon Barrel (RB1) γ spectrum into the RPCs gaps

thisLHC like test beam (this week)LHC like test beam (this week)

Production and control of Bakelite Production and control of Bakelite

Resistivity range :• 2/3 of production in the range ρ20 = 2-5 1010 Ω cm• 100% of production in the range ρ20 = 1-6 1010 Ω cm

Roughness range :• Ra ≤ 0.2 µm

Resistivity range :• 2/3 of production in the range ρ20 = 2-5 1010 Ω cm• 100% of production in the range ρ20 = 1-6 1010 Ω cm

Roughness range :• Ra ≤ 0.2 µm

Totals for barrel≈ 4000 Slabs ≈14000 m2

Totals for barrel≈ 4000 Slabs ≈14000 m2

These are the first 400 slabsThese are the first 400 slabs

A wrapping machine allows to have a protecting film on each face of the slab

A wrapping machine allows to have a protecting film on each face of the slab

The table to measure the resistiviryThe table to measure the resistiviry

First results from the mass productionFirst results from the mass production

CMS MEASURED

21,4%

1,2%

27,2%24,1%

9,2% 10,1%6,7%

0%5%

10%15%20%25%30%

BLACK

WHITE

YELL

OW RED

GREENBLU

E

BLACK

RESISTIVITY COLOR CODE[5 – 6.3]BLUE

[4 – 5 [GREEN

[3 – 4 [RED

[2 – 3[YELLOW

[0.95 – 2[WHITE

< 0.95 or >6.3BLACK

RANGE

(x 1010 Ω cm)COLOR CODE

400 slabs

Bakelite AgeingBakelite Ageing

Gamma (137Cs) Irradiation Facility

Gamma (137Cs) Irradiation Facility

(Α) ρ vs Temp. (0 C)(B) ρ vs Time (days)(C) Temp. vs Time

ρ no Temp. corrected

A

B

C

Source ON

Source OFF

Melaminic sample

The ASIC DesignThe ASIC Design

Technology: 0.8 µm BiCMOS ofAMS8 channelsPower supplies: +5 V; GNDPower consumption: ~ 45mW/channel

Technology: 0.8 µm BiCMOS ofAMS8 channelsPower supplies: +5 V; GNDPower consumption: ~ 45mW/channel

In

Vtest Preamplifier

Dummy Preamplifier

Gain stage

Vbias Vth Vdrive

Zero-crossingDiscriminator

Outp

OutmDriver

Vmon

Monostable

Improvements:Input impedance = 15 ΩBetter threshold uniformityImproved timingperformance

Improvements:Input impedance = 15 ΩBetter threshold uniformityImproved timingperformance

Discriminator Response in the dynamic rangeDiscriminator Response in the dynamic range

∆T ~ 10 ns

One-Shot response

Zero-crossing Discriminator response

∆T < 1 ns

Zero-Crossing Discriminator response

∆ t < 1 ns

Qth = 20 fC 1 fC < Qov < 20 pC

Test Results (14 prototypes)Test Results (14 prototypes)

In-chip delaydispersion

Typical timing response

Qth = 30 fC

0

1

2

3

4

5

6

1 10 100 1000 10000Qov (fC)

|Tm

ax -

Tmin

| (ns

)

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

23

23.5

24

24.5

25

25.5

26

26.5

1 10 100 1000 10000Qov (fC)

<Tim

e (n

s)>

[Arb

itrar

y ze

ro] Chip 1

Chip 2Chip 3Chip 4

VLSI selection and FE board testVLSI selection and FE board test

The VLSI will be grouped by:

•Threshold value at a fixed Vgain•Signal propagation delay and time spread among the 8 channels

The VLSI will be grouped by:

•Threshold value at a fixed Vgain•Signal propagation delay and time spread among the 8 channels

FE board tests:

•Measure of Vpower and Vref•Check of DAC dynamics range•Gains equalization•Width adjustment of the one-shot output•Height adjustment of the output pulse•Electronic check of the “test-branch” and of the “reading-branch”•Delay time measure•Burn in

FE board tests:

•Measure of Vpower and Vref•Check of DAC dynamics range•Gains equalization•Width adjustment of the one-shot output•Height adjustment of the output pulse•Electronic check of the “test-branch” and of the “reading-branch”•Delay time measure•Burn in

Gamma irradiation Gamma irradiation

Triga Mark II 250 kW Reactor in PAVIA

Neutron spectrum afterthe boral window

Neutron spectrum afterthe boral window

Simulation

NeutronEnergy

Φn

(n/cm2 sec)Total

(n/cm2 sec)

En < 0.4 eV 1.6 x 10 3

0.4 eV<En<10 KeV 3.4 x 10 5

10 KeV<En<10 MeV 2.5 x 10 55.9 x 10 5

The FE boards were put in the Thermal Column of the Reactor justin front of a boral window (to deplete thermal component)

The FE boards were put in the Thermal Column of the Reactor justin front of a boral window (to deplete thermal component)

Average CHIP SEU RATE

0,012

0,015

0,018

0,021

0,024

0 5 10 15 20

Fast Neutron Fluence ( x 1010 cm-2)

Ave

rage

CH

IP R

ATE

(Hz)

Assuming6 x 105 cm-2 s-1

Assuming6 x 105 cm-2 s-1

PRELIMINARY

PRELIMINARY

Each OR of 8 channels ( 1 chip) was counted (with open input )at Reactor ON and OFF to measure spurious neutron inducedevents (Single Event Upset)

Each OR of 8 channels ( 1 chip) was counted (with open input )at Reactor ON and OFF to measure spurious neutron inducedevents (Single Event Upset)

UCL Neutron Facilities at Louvain

Wide spectrum neutron source:

* beam from variable shaping collimator

* maximum irradiation area 25x25 cm 2 @ 2m from target

* protons on Be target @ 15µA maximum current

* yield of 15µA of 65 MeV protons at 2m: 3.6x10 7 n/cm 2 /s

* flat spectrum up to proton energy (65MeV maximum)

8 hours beam on the 27 June

UCL Neutron Facilities at Louvain

Wide spectrum neutron source:

* beam from variable shaping collimator

* maximum irradiation area 25x25 cm 2 @ 2m from target

* protons on Be target @ 15µA maximum current

* yield of 15µA of 65 MeV protons at 2m: 3.6x10 7 n/cm 2 /s

* flat spectrum up to proton energy (65MeV maximum)

8 hours beam on the 27 June

Neutron irradiationNeutron irradiation

Front-End electronicsSchedule

Front-End electronicsSchedule

• VLSI pre-production (1000 pieces): done

• Test of pre-production June 2000

• Neutron irradiation tests at Louvain June 2000

• Start tender of VLSI July 2000

• Start tender of FE boards September 2000

• VLSI pre-production (1000 pieces): done

• Test of pre-production June 2000

• Neutron irradiation tests at Louvain June 2000

• Start tender of VLSI July 2000

• Start tender of FE boards September 2000

Production OverviewProduction Overview

Barrel• Single gaps from industry

• RB1 assembled in China

• RB2 assembled in Italy

• RB3 assembled in Bulgaria

• RB4 assembled in Italy

Problems

Bulgarian funds not fully established

Barrel• Single gaps from industry

• RB1 assembled in China

• RB2 assembled in Italy

• RB3 assembled in Bulgaria

• RB4 assembled in Italy

Problems

Bulgarian funds not fully established

Forward• Single gaps from Korea

• RE1 assembled in China

• RE n/1 assembled in Korea

• RB n/2 assembled in Pakistan

• RB n/3 assembled in Pakistan

Problems

Still missing money (.7 -1.0 KCHF)

Forward• Single gaps from Korea

• RE1 assembled in China

• RE n/1 assembled in Korea

• RB n/2 assembled in Pakistan

• RB n/3 assembled in Pakistan

Problems

Still missing money (.7 -1.0 KCHF)

Resistive Plate ChambersBarrel

Resistive Plate ChambersBarrel

• Production of Bakelite already started (10% in February)

• Tender for single gap completed

• Front-end VLSI pre-production completed (1000 chips)

• Test towers under construction in Bari

• The first RB2 chamber ready by June

• Final front-end board ready

• Front-end irradiation test under way

• Tenders for VLSI and FE board in July

• Production of Bakelite already started (10% in February)

• Tender for single gap completed

• Front-end VLSI pre-production completed (1000 chips)

• Test towers under construction in Bari

• The first RB2 chamber ready by June

• Final front-end board ready

• Front-end irradiation test under way

• Tenders for VLSI and FE board in JulyTest towers

Assembly table

Resistive Plate ChambersForward

Resistive Plate ChambersForward

Definition of the single gaps design done

Definition of the mechanics and the assembly procedure May

Construction of single gaps in Korea June

Assembly of a forward sector in Korea and Pakistan July

Definition of the single gaps design done

Definition of the mechanics and the assembly procedure May

Construction of single gaps in Korea June

Assembly of a forward sector in Korea and Pakistan July

The forward single gap will be built in Korea using Italian bakeliteThe chambers will be assembled in China, Korea, Pakistan

The forward single gap will be built in Korea using Italian bakeliteThe chambers will be assembled in China, Korea, Pakistan

Production scheduleProduction schedule

Barrel:• Follow Dt production schedule• One wheel by middle of 2001• Few chambers by the end of the year

•Forward:• Design frozen by te end of the year

Barrel:• Follow Dt production schedule• One wheel by middle of 2001• Few chambers by the end of the year

•Forward:• Design frozen by te end of the year