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Electroluminescence yields in MicroMegas , THGEM and GEM. H. Natal da Luz 1 , C.M.B. Monteiro 1 , J.M.F. dos Santos 1 , C. Balan 1 , E.D.C. Freitas 1 , J.F.C.A. Veloso 2 , A. Breskin 3 , T. Papaevangelou 4 , I. Giomataris 4. 1 University of Coimbra, Portugal
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Electroluminescence yields in MicroMegas, THGEM and GEM H. Natal da Luz1, C.M.B. Monteiro1, J.M.F. dos Santos1, C. Balan1, E.D.C. Freitas1, J.F.C.A. Veloso2, A. Breskin3, T. Papaevangelou4, I. Giomataris4 • 1University of Coimbra, Portugal • 2University of Aveiro, Portugal • 3Weizmann Institute of Sciences, Israel • 4Centre d’ÉtudesNucléaires de Saclay, France
Outline • Motivation; • Experimental setups withdifferentMPGDsand UV sensitiveLAAPDs; • Methods for determinationofElectro-luminescenceyields; • Results; • Conclusions.
Motivation • Rareeventexperiments (eg.: darkmattersearch, neutrinolessdouble beta decay) cantakeadvantagesofreadingchargeandscintillationlightproducedbyMPGDs; • Decouplingofelectronicnoise; • Usuallymuchbetter SNR.
MPGD scintillation vs. charge readout THGEM/GEM MicroMegas Gap: 50 mm Holediameter: 25 mm • Thickness: 0.4 mm • Hole diameter: 0.4 mm • Rim: 0.1 mm
Charge (a) and scintillation (b) pulse-height distributions in MM LAAPD gain ~ 30
MM EL Yield ------------------------
MM Chargegainfluctuations (Xe) 22 keV X-rays
MM gain in scintillation-readout (Gtot = primary charge/charge out from LAAPD) LAAPD gain ~ 30
Charge-to-scintillationgain ratio Lower E/p favours excitations
Absolute EL Yield “out” of MM (Xe) • Double mesh, uniform field scintillation gap yields 466 photons/e-/cm @4.1 kV/cm/bar
THGEM GainsinXe APD gain ~150
Conclusions • Double mesh, uniform field scintillation gap yields 466 photons/e-/cm @4.1 kV/cm/bar