MICROMEGAS DHCAL 2011 - Intro Several attractive features for a semi-DHCAL large area, high efficiency, low fired pad multiplicity, standard gas mixtures, proportional mode (semi-digital info.), resolution of 5-10 ns (CLIC), high rate capability (forward CAL), gain real time correction for P/T variations 1 m2 ~ 6x48x32 cm2 1x1 m2 MICROMEGAS chamber design 6 boards with embedded front-end & Bulk Micromegas Pads of 1x1 cm2 and dead zone < 2% inside chamber Several beam tests in the past 3 years @ CERN 2008 : prototype of 16x6 cm2 with analog electronics (SPS and PS) 2009 : prototype of 32x8 cm2 and 48x32 cm2 with digital electronics (PS) 2010 : first Micromegas prototype of 1x1 m2 (SPS) Publications/proceedings : JINST 4 P11023, JINST 4 P11011, JINST 5 P01013, IWLC 2010 proc., CALOR 2010 proc.

MICROMEGAS DHCAL 2011 - TB request Continuation of 2011 tests With a few 1X1 m2 chambers with optimized electronics (MICROROC) Standalone test Detailed efficiency scan 150 GeV/c muons Rate below 1 kHz RD51 telescope (H4) 3000 triggers per pad x 104 pads 25 Hz effective acquisition rate → 15 days Combined test Chamber behaviour in showers Insert all available chambers (2-5) in tungsten and/or steel CALICE structures Test area preferred by CALICE : H8 Sample showers at different depths of the calorimeters 2 weeks in July/August in H4 To be combined with 2 weeks of RD51 request, so at the end : 1 month in summer 2 weeks in Oct./Nov. in H8 PS : special hazard : use of flamable gas (argon/isobutane 95/5), small volume (3l/chamber) and flow (3l/h)