G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Status Report on triple-GEM detector M.Alfonsi 1,...

G.Bencivenni LNF/INFN Muon Meeting 21-October-2002

Status Report on Status Report on triple-GEM detectortriple-GEM detector

M.Alfonsi1, G. Bencivenni1, W. Bonivento2,A.Cardini2,C. Deplano2,

P. de Simone1, F.Murtas1, D.Pinci2,3, M. Poli-Lener1, D. Raspino2

• 1 - Laboratori Nazionali di Frascati - INFN, Frascati , Italy

• 2 - Sezione INFN di Cagliari – Cagliari, Italy

• 3 - Università degli Studi di Cagliari, Cagliari, Italy


2002 tests beam summary

Module-0 test results (preliminary)

New aging test results (preliminary)

Future Plans

OUTLINE


Discharge probability < 10-12

1 %inefficiency due to re-charging time

End of efficiency plateau given by the limit on the discharge probability of 10-12

During the PSI test each detector integratedwithout any damage or aging effect about 5000 discharges, corresponding to a dischargeprobability per incident particle of 10-12 in 10 years at LHCb.

Discharge probability per incident particle

Start of efficiency plateau:99% in 25 ns per station

PSI beam test (June 2002): discharge studies


CERN test (July 2002): fast gas efficiency

Single detector

Effi

cie

ncy in

25 n

s

99%

Effi

cie

ncy in

25 n

s

Two detector in OR

These results were obtained with a thr of 3 fC


Discharge probability < 10-

12

99% efficiency in 25 ns of two chambers in OR(measured after 10 years LHCb equivalent)

1250 V 1315 V

at least 65 V wide working region

PSI + CERN beam test

Ar/CO2/CF4= 45/15/40


Module-0 test at T11-PS (october 2002)

Two coupled triple-GEM;

active area: 20x24 cm2 (top side of each GEM divided in 6 sectors);

2x192 pads (10x25 mm2);

2x120 pads instrumented with ASDQ fee:

HIGH operating threshold: ~ 200mV 5 fC


Chamber A: one sector of one GEM foil was disconnected becausethe limiting resistor was broken and the whole GEM had to be supplied at lower voltage

Chamber B: OK

Total Efficiency

Chamber B

Total Efficiency

Chamber A



200 mm

240 mm

34 mm

Holes for SMD decoupling resistor

G10 Frame


Good uniformity even though efficiency is a little bit low, due to high thres hold

(5 fC instead of3 fC)


efficiency in 25 ns

Chamber B

efficiency in 25 ns

A or B



fine scan measurements with small crossed scintillator fingers

Chamber B

Cluster size uniformity

Good and uniform cluster size along the pads

Chamber B

Cluster size-fine scan

CS=1.1 onpad center

CS=1.2 onpad edge


10 years of LHCb R1-M1

60-20-20G=2x104

Aging test(I)By irradiating the detector with an X-rays flux of 50 MHz/cm2 :

~ 20 C/cm2 was integrated with 60-20-20 @ G= 2x104 (15 LHCb Y)

~ 4.5 C/cm2 was integrated with 45-15-40 @ G= 6x103 (10 LHCb Y)

Gain change less than 5%


45-15-40G=6x103

P and T variations are corrected by using a low irradiated 3-GEM chamber

HV= 1230

HV= 1280


Aging test(II)45-15-40G=6x103

5.9 keV X-rayspectrum

5.9 keV X-ray: charge peak

stability duringirradiation

5.9 keV X-ray: peak RMS stability during

irradiation

45-15-40G=6x103


45-15-40G=6x103



iso-C4H10 aging test (very preliminary)

Ar/CF4/iso-C4H10 = 65/28/7 at 1030 V – G=1x 104

To simulate 10 years of LHCb R1-M1, at a gain of104, a charge of 6.4 C/cm2

must be integrated

~ 5 years of LHCb R1-M1

in progress !!!

HV= 1030


Future Plans

ASDQ thr lowering (from 5 fC to 3 fC) by means of a better LV distribution (splitter board) and then possible test at BTF (LNF)

ENEA-Casaccia test with (1.25 MeV) from Co60

for large area irradiation

Light version design: Module 0.1 (light honeycomb panel …)

PSI/CERN beam tests

G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Status Report on triple-GEM detector M.Alfonsi 1,...

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