A PiggyBack Micromegas Ioannis Giomataris – CEA-Saclay M. S. Dixit et al., NIMA 518 (2004) 521 M. Dixit et al.,NIMA581 (2007) 254 P. Colas et al., NIMA535(2004)506 ATLAS resistive planes MAMA project P. Colas et al., NIMA535(2004)506 I. Giomataris

Micromegas on a resistive thin ceramic substrate Readout pixels or strips is an independent element Signal propagates through capacitive coupling without loss If t2<<t12/1 Ceramic provide large dynamic range of dielectric constants

Test chamber I. Giomataris

I. Giomataris

Signal induced at the read-out anode Efficiency Better than 90% Argon + 5% Isobutane Fe55-109 source Efficiency Better than 90% I. Giomataris

Argon + 5% Isobutane Cd-109 source I. Giomataris

In Neon mixture I. Giomataris

Gain stability: decrease of the gain the first 100 minutes I. Giomataris

I. Giomataris

Advantages Detector dissociated from read-out plane It provides spark protection Excellent outgassing – Seal detector Read-out of CMOS pixel ASICs Negligible dead space I. Giomataris

PiggyBack and TimePix Parer in preparation:A Piggyback resistive Micromegas  D. Attie, P. Colas, I. Giomataris, A. Gongadze, R. De Oliveira, Th. Papaevangelou, A. Peyaud I. Giomataris