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 Laboratori Nazionali di Frascati - INFN, Frascati, Italy 2 - Sezione INFN di Cagliari – Cagliari, Italy 3 - Università degli Studi di Cagliari, Cagliari, Italy

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

G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Discharge probability < %  inefficiency due to re-charging time End of efficiency plateau given by the limit on the discharge probability of 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 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

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

G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Discharge probability < % 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

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

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)

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

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

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

G.Bencivenni LNF/INFNMuon Meeting 21-October years of LHCb R1-M 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 G= 2x10 4 (15 LHCb Y) ~ 4.5 C/cm 2 was integrated with G= 6x10 3 (10 LHCb Y) Gain change less than 5% 10 years of LHCb R1-M G=6x10 3 P and T variations are corrected by using a low irradiated 3-GEM chamber HV= 1230 HV= 1280

G.Bencivenni LNF/INFNMuon Meeting 21-October-2002 Aging test(II) G=6x keV X-ray spectrum 5.9 keV X-ray: charge peak stability during irradiation 5.9 keV X-ray: peak RMS stability during irradiation G=6x years of LHCb R1-M G=6x years of LHCb R1-M1

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

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