Progress with pixelised readout of gaseous detectors ALCPG 2011 – Eugene 20 March 2011 Jan Timmermans NIKHEF/DESY On behalf of the Bonn/CERN/Freiburg/Nikhef/Saclay groups

Full post-processing of a TimePix · Timepix chip + SiProt + Ingrid: Timepix chip: 256x256 pixels pixel: 55x55 μm2 active surface: 14x14 mm2 MESA+: Ingrid IMT Neuchatel: 15 or 20 μm highly resistive aSi:H protection layer Now also Si3N4 protection layers (7 μm)

Terminology Timepix = 256x256 pixel CMOS readout chip, with time measurement per pixel Siprot (amorphous Si) or Si3N4 highly resistive protection layers Ingrid = Timepix + ‘Siprot’ + integrated (Micromegas-like) conductive grid (NIKHEF and Mesa+ Univ. Twente (NL)); now also at IZM Berlin + Bonn Octopuce = 8 x Ingrid (NIKHEF/Saclay))

Pad readout vs. Pixel readout Pad size ~1x5 mm2 or ~3x7 mm2 Timepix pixel size 55x55 (μm)2 Pad TPC ~ 106 pads; several 109 3D-voxels CMOS pixel readout ~ 2.109 ‘pads’ (but ‘only’ ~ 4.104 chips); ~ 1012 3D voxels # pads/pixels might be problem for software, but occupancy “rather low”

72x24 pads of ~3x7 mm2 5 GeV e- beam B = 1 T TimePix chip 14x14 mm2

Two-track separation: Will be diffusion limited In this example: 5 pixels = 275 μm Diffusion at 4T in Ar/CF4/iC4H10 is ~ 20√200 = 300 μm 256x256 pixels 55x55 (μm)2 275 μm

Single chips / 3x3 chip squares at Twente facilities at Twente U can (at most) handle 4 inch wafers practically at most 3x3 chips can be handled at once several days of processing (+ working) time for one run Try to find a place which can manufacture Ingrids on a 8 inch wafer scale Best candidate currently: (Berlin)

Detector Technologies 3-GEM 8 (2x4) Timepix InGrid 8 Timepix „Octopuce“ underneath a 3-GEM stack NIKHEF Saclay Twente Bonn Freiburg

Detector Technologies First „large area“ ( 2.8 x 5.6 cm2, 500k „channels“) tracking devices (EUDET): 3-GEM 8 Timepix InGrid 8 Timepix NIKHEF Saclay Twente Bonn Freiburg

1st attempt at IZM: „GEMGrids“

„GEMGrids“ – work (in principle) first signals seen in Bonn setup with 55-Fe source challenges / problems limited yield (~ 1 / 6 structures working so far...) sparking at the edges limited HV  limited efficiency to be understood T. Krautscheid, Bonn

Activities in 2010 at DESY test beam 4-chip/Ingrid tests in March; 3 days OK Single Ingrid tests in May combined with EUDET telescope: some synchro problems Single Ingrid tests in Aug/Sept with Bonnie Chow (DESY summer student); one run combined with ZEUS/MVD telescope; synchro seems OK, some problem with Endianness of various PCs (or software?) Octopuce (= 8 Ingrids) test on LP with magnet in December together with Saclay group

Track backscattering from chip (=anode)

Handshaked Pixelman operation based on Uwe Renz Pixelman plugin Work performed with Uwe Renz (and Martin Killenberg support) and with DESY summerstudent Bonnie Chow Detector used is the (2009) “8 um” Ingrid

Track scattering at grid (or anode) Out-of-time track Beam entering through cathode

DESY Nov/Dec test beam e- test beam 5 GeV Preparation/installation Octopuce detector in gastestbox on Monday 29/11 Some test runs in gastestbox w. beam on Tuesday 30/11 Mounting detector module on LPTPC evening Tuesday 30/11 Flushing with pure He and from morning Wed 1/12 with He/isoButane 80/20 (5-6 hours per 40l gas bottle at 9 bar when full) First data taking evening Thu 2/12 without B-field B = 1 T available from Fri 3/12 15:00 Several data taking runs until Sat 4/12 ~12:00 Data taking rather slow (1 Hz), because of only (old) PC that worked with Muros and 8-chips

8 Ingrids on daughter board LPTPC with 7 detector slots inside1 T solenoid

EUDET 2010 - Octopuce - P. Colas 29/09/2010 EUDET 2010 - Octopuce - P. Colas 18

LCTPC WP phone meeting #119 TPC at 0T He/Iso 80/20 Vmesh = 380V Time mode December 9, 2010 LCTPC WP phone meeting #119 19

LCTPC WP phone meeting #119 TPC at 1T He/Iso 80/20 Vmesh = 380V Time mode December 9, 2010 LCTPC WP phone meeting #119 20

The last trigger taken: 4 Dec 2010, 11:06 He/iC4H10 80/20 Vgrid = -400 V B = 1 T

Summary (including some ‘old’ statements) 8 μm thick Si3N4 protection layers seem sufficient Problems with readout of 4-fold Timepix/Ingrid (still) being investigated Successful standalone “handshaked” operation with early shutter opening Common data acquisition with Zeus telescope, running EUDAQ, succeeded Short but rather successful data taking with Octopuce module at Large Prototype TPC at B = 0 and 1 T

Future Wafer-scale production of Ingrids/GEMgrids at IZM Berlin (all single steps of process tried out); hopefully 1st successful production in next few months Construct 2nd Octopuce and test at LP with T2K gas Move to new (faster) readout: e.g. Muros/Pixelman  “Relaxed” Longer term (2(?) years): development of “full” scale LP module with ~64 – 119 Ingrids; integrated design Ingrid, cooling, FPGA readout and data transfer Timepix2 with better time resolution and improved readout

2nd road at IZM: Ingrids transfer original „Twente“ process to 8´´ very successful 1st attempt on dummy wafers development after dicing IZM+Y.Bilevych,Bonn extremely regular...