1. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Status Report on triple-GEM detector M.Alfonsi 1, G. Bencivenni 1, W. Bonivento 2,A.Cardini 2,C. Deplano 2, P. de Simone 1, F.Murtas 1, D.Pinci 2,3, M. Poli-Lener 1, D. Raspino 2 1 - Laboratori Nazionali di Frascati - INFN, Frascati, Italy 2 - Sezione INFN di Cagliari – Cagliari, Italy 3 - Università degli Studi di Cagliari, Cagliari, Italy

2. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002  2002 tests beam summary  Module-0 test results (preliminary)  New aging test results (preliminary)  Future Plans OUTLINE

3. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 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 integrated without any damage or aging effect about 5000 discharges, corresponding to a discharge probability 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

4. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 CERN test (July 2002): fast gas efficiency Single detector Efficiency in 25 ns 99% Efficiency in 25 ns Two detector in OR These results were obtained with a thr of 3 fC

5. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Discharge probability < 10 -12 99% efficiency in 25 ns of two chambers in OR (measured after 10 years LHCb equivalent) 1250 V1315 V at least 65 V wide working region PSI + CERN beam test Ar/CO 2 /CF 4 = 45/15/40

6. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Module-0 test at T11-PS (october 2002)  Two coupled triple-GEM;  active area: 20x24 cm 2 (top side of each GEM divided in 6 sectors);  2x192 pads (10x25 mm 2 );  2x120 pads instrumented with ASDQ fee: HIGH operating threshold: ~ 200mV 5 fC

7. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Chamber A: one sector of one GEM foil was disconnected because the 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 Module-0 test at T11-PS (october 2002)

8. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 200 mm 240 mm 34 mm Holes for SMD decoupling resistor G10 Frame

9. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Good uniformity even though efficiency is a little bit low, due to high thres hold (5 fC instead of3 fC) Module-0 test at T11-PS (october 2002) efficiency in 25 ns Chamber B efficiency in 25 ns A or B

10. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Module-0 test at T11-PS (october 2002) 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 on pad center CS=1.2 on pad edge

11. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 10 years of LHCb R1-M1 60-20-20 G=2x10 4 Aging test(I) By irradiating the detector with an X-rays flux of 50 MHz/cm 2 : ~ 20 C/cm 2 was integrated with 60-20-20 @ G= 2x10 4 (15 LHCb Y) ~ 4.5 C/cm 2 was integrated with 45-15-40 @ G= 6x10 3 (10 LHCb Y) Gain change less than 5% 10 years of LHCb R1-M1 45-15-40 G=6x10 3 P and T variations are corrected by using a low irradiated 3-GEM chamber HV= 1230 HV= 1280

12. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Aging test(II) 45-15-40 G=6x10 3 5.9 keV X-ray spectrum 5.9 keV X-ray: charge peak stability during irradiation 5.9 keV X-ray: peak RMS stability during irradiation 45-15-40 G=6x10 3 10 years of LHCb R1-M1 45-15-40 G=6x10 3 10 years of LHCb R1-M1

13. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 iso-C 4 H 10 aging test (very preliminary) Ar/CF 4 /iso-C 4 H 10 = 65/28/7 at 1030 V – G=1x 10 4 To simulate 10 years of LHCb R1-M1, at a gain of 10 4, a charge of 6.4 C/cm 2 must be integrated ~ 5 years of LHCb R1-M1 in progress !!! HV= 1030

14. G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 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 Co 60 for large area irradiation  Light version design: Module 0.1 (light honeycomb panel …)  PSI/CERN beam tests