RPC project

Update on the trigger Two members of the RPC group are active in the trigger simulation to review and cross check all the figures

• Production of gaps The production of CMS gaps has started.

• Tests in Summer/Autumn 2001 Irradiation with gammas and neutrons DT-RPC test RPC-Link Board test

RPC project

Update on the trigger Two members of the RPC group are active in the trigger simulation to review and cross check all the figures

• Production of gaps The production of CMS gaps has started.

• Tests in Summer/Autumn 2001 Irradiation with gammas and neutrons DT-RPC test RPC-Link Board test

50 Hz/cm2

Neutron factor 3

10%

100%1/0 5 1/041/031/02

70%

01 02 03 04 05 06

1/06

120 RB1, 120 RB2, 120 RB3, 40 RB4

80 RB4

Install. Milestones (V.31)

# of chambers needed for install. in SX

Trialwheel 0 7/04

readiness wheel +2 8/03

Readiness wheel -2 8/04

End of SXinstallation 12/04

End of UXinstallation 6/05

< install. of wheels 0 ,+1 >

end +2 +1,0 2/04

< installation of wheels +2, -1, -2>

Begin mass production 9/ 01

500 gap

Maggio 02

500 gap

Maggio 02

820 gap

Febbraio 03

820 gap

Febbraio 03

Gap production at GT

So far 40 gaps (RB3 type) have been produced). The goal is to have 100 gaps ready for the end of the year.

Quality control: • pressure test up to 20 mbar• HV test up to 8000 in pure C2H2F4 ( I < 3A)• Quality of the oil coating ( by opening 1/10 of chambers)

Plan for next year: J F M A M J J A S O N D 40 140 240 330 450 500 550 600 650 650 650 650

Bakelite procurement: 300 foils arriving at GT in January 300 in production in January

Gap production at GT

So far 40 gaps (RB3 type) have been produced). The goal is to have 100 gaps ready for the end of the year.

Quality control: • pressure test up to 20 mbar• HV test up to 8000 in pure C2H2F4 ( I < 3A)• Quality of the oil coating ( by opening 1/10 of chambers)

Plan for next year: J F M A M J J A S O N D 40 140 240 330 450 500 550 600 650 650 650 650

Bakelite procurement: 300 foils arriving at GT in January 300 in production in January

Assembly at GT

Double gap assembly foreseen at GT. Tools in preparation.Assembly should start very soon, but space, resources and schedule at GT still to de defined. The option to use additional INFN manpower for the assembly has been very preliminary discussed in the INFN RPC committee

Chamber assembly at GT: Idem

Chamber assembly in Sofia : ready Chamber assembly in Pavia: site in preparation

Chamber assembly in Bari: ready

Assembly at GT

Double gap assembly foreseen at GT. Tools in preparation.Assembly should start very soon, but space, resources and schedule at GT still to de defined. The option to use additional INFN manpower for the assembly has been very preliminary discussed in the INFN RPC committee

Chamber assembly at GT: Idem

Chamber assembly in Sofia : ready Chamber assembly in Pavia: site in preparation

Chamber assembly in Bari: ready

DT + RPC under tested at ISR

DT + RPC at GIF

Combined DT-RPC testCombined DT-RPC test

Efficiency Efficiency

s

ss

P

P

1

No SF6; data with SF6 being analysed No SF6; data with SF6 being analysed

Rate from cluster countingRate from cluster counting

Efficiency 99%

Strip # is fired if it the median of the considered cluster

Strip # is fired if it the median of the considered cluster

No SF6; data with SF6 being analysed No SF6; data with SF6 being analysed

Hit countingHit counting Cluster sizeCluster size

No SF6; data with SF6 being analysed No SF6; data with SF6 being analysed

even

ts

Distributions of residuals between reconstructed impact point from DT and the median strip in the RPC cluster

Spatial resolutionSpatial resolution

Gamma irradiation @ GIFGamma irradiation @ GIF

“Oiled” chamber at GIF from October 2000 to May 2001:• Monitor rate and current• Study the efficiency to cosmic

“Oiled” chamber at GIF from October 2000 to May 2001:• Monitor rate and current• Study the efficiency to cosmic

Before irradiationBefore irradiation

Two month after irradiationTwo month after irradiation

Efficiency Efficiency

Rate Rate

Monitor the chamber at different source conditions (ABS)Monitor the chamber at different source conditions (ABS)

NABS = number of hit

expected at a given ABS, as computed by the simulation

The system resistance remains constant during irradiation

The system resistance remains constant during irradiation

If R is the total resistance of the system,the quantity Hvgas should be invariant:

If R is the total resistance of the system,the quantity Hvgas should be invariant: HV HVgas

LegnaroLegnaro (Padova INFN) (Padova INFN)

1717CiCi 252 252Cf:Cf:

a-3%a-3% spontaneous fission;spontaneous fission;

b-b-97%97% decay decay

1 gap oiled1 gap not oiled1 gap oiled1 gap not oiled

3.8 n/fission3.8 n/fission

EEavav= 2.14 = 2.14 MeVMeV

Neutron irradiation Neutron irradiation

Measure the sensitivity to low energy neutrons

Measure the sensitivity to low energy neutrons

Lovain Centre de Recherches du Cyclotron (Louvain la Neuve, Belgium)

Reaction: 9Be (d,n)

Neutron Flux at 90 cm:

8.15 107 n/cm2 s A

3 double gap RPCs

Neutron irradiationNeutron irradiation

90 cm from the target

Single gap sensitivity at low energy: (2.5-3.5) 10-4

Single gap sensitivity at high energy: (2-3) 10-3

Same chamber used for both measurements

No difference between the oiled and the no oiled gaps

Single gap sensitivity at low energy: (2.5-3.5) 10-4

Single gap sensitivity at high energy: (2-3) 10-3

Same chamber used for both measurements

No difference between the oiled and the no oiled gaps

Neutron sensityityNeutron sensityity

Double gap sensitivity is twice the single gap value

Double gap sensitivity is twice the single gap value

1 gap with oil coating

(Resistivity: 1.4 1010

cm)

1 gap without oil coating

(Resistivity: 3.2 109 cm)

Gas mixture: 96.5% C2H2F4

3.5% i-

C4H10

1 gap with oil coating

(Resistivity: 1.4 1010

cm)

1 gap without oil coating

(Resistivity: 3.2 109 cm)

Gas mixture: 96.5% C2H2F4

3.5% i-

C4H10

The Neutron Flux can be adjusted by tuning the current of the beam:

at 90 cm= 8.15 107 n/cm2 s A

The Neutron Flux can be adjusted by tuning the current of the beam:

at 90 cm= 8.15 107 n/cm2 s A

n ageing @Louvain n ageing @Louvain

# Measurements Dose (Gy)

Charge (C/cm2 gap)

n fluence (n/cm2)

1 0 0 before irradiation

2 4 710-4 2 1011

3 50 0.002 1 1012

4 50 0.002 After irradiation

# Measurements Dose (Gy)

Charge (C/cm2 gap)

n fluence (n/cm2)

1 0 0 before irradiation

2 4 710-4 2 1011

3 50 0.002 1 1012

4 50 0.002 After irradiation

Irradiation schedule

High neutron fluxes (2-3 107 n/s cm2)

High neutron fluxes (2-3 107 n/s cm2)

Chamber noise monitoringChamber noise monitoring

At constant neutron flux the contribution of the neutron activation must be added.

At constant neutron flux the contribution of the neutron activation must be added.

The chamber noise is decreasing following the decay law

The chamber noise is decreasing following the decay law

0

500

1000

1500

2000

2500

3000

0 5 10 15 20 25 30 35 40 45 50

Irradiation time(min)

rate

(H

z/cm

2)

non oiled GAP

BEAM ON

BEAM OFF

oiled gap

-

20

40

60

80

100

8 8.2 8.4 8.6 8.8 9 9.2 9.4 9.6 9.8 10 10.2 10.4 10.6 10.8

HV (kV)

Effic

ienc

y (%

)

Before irradiation

After Irradiation

oiled gap

00.5

1

1.52

2.53

3.5

44.5

5

8 8.2 8.4 8.6 8.8 9 9.2 9.4 9.6 9.8 10 10.2 10.4 10.6 10.8

HV (kV)

rate

(H

z/cm

2)

Before Irrad.

After Irrad.

The chamber efficiency was measured using cosmic muon triggers

The chamber efficiency was measured using cosmic muon triggers

Efficiency and noise: before after irradiationEfficiency and noise: before after irradiation

Non oiled gap

0

1020

30

40

5060

70

80

8.2 8.4 8.6 8.8 9 9.2 9.4 9.6 9.8 10 10.2 10.4

HV (kV)

Ra

te (

Hz/

cm

2)

Before irrad.

After irrad.

Non oiled gap

-

20

40

60

80

100

8.2 8.4 8.6 8.8 9 9.2 9.4 9.6 9.8 10 10.2 10.4 10.6

HV (kV)

Rate

(H

z/c

m2)

Before irrad.

After irrad.

Conclusion Conclusion

• Satisfactory results on the performance of the RPC system

• Barrel production has started

• The schedule at GT needs some refining

• Man power required (art. 2222)

• Specification for the gas system defined (tender ready to go)

• Pavia site in preparation

• Satisfactory results on the performance of the RPC system

• Barrel production has started

• The schedule at GT needs some refining

• Man power required (art. 2222)

• Specification for the gas system defined (tender ready to go)

• Pavia site in preparation