MPGD TECHNOLOGIES AND PRODUCTION GEMMicromegas Resistive MSGC (NEW!) Rui De Oliveira 7/12/20111Rui De Oliveira

GEMGEM 7/12/20112Rui De Oliveira

7/12/2011 Rui De Oliveira 3 GEM Foil Present max size 1.2m x 0.6m Future max size 2m x 0.6m (thanks to new equipments)

7/12/2011 Rui De Oliveira 4 Base material : Polyimide 50um + 5um on both sides Double mask Vs single Mask Base material Hole patterning in Cu Polyimide etch Bottom electro etch Second Polyimide Etch Limited to 40cm x 40cm due to Mask precision and alignment Limited to 2m x 60cm due to Base material Equipment Double maskSingle mask

7/12/2011Rui De Oliveira5 Double mask Vs single Mask Similar patterns, similar behavior Same material Angles can be adjusted to application (High gain –> Charging up)

COMPASS 6 GEM double mask examples LHCb-Muon trigger TOTEM GEMs, T. Hilden,V. Greco… Window Drift electrode GEM stack Pad Plane Support & Media-Distribution Cooling Support & LV- Distribution Front-End Electronic Shielding Cover & Read-out Plane B. Surrow, STAR GEM 7/12/2011Rui De Oliveira Production quantities : around 500 GEMs/ year in average

7 GEM Single mask examples KLOE – Cylindrical 3 GEM Detector GEM 800mm x 500mm CMS 3 GEM Detector GEM 1.1m x 500mm Present production rate : 100 Gem / year Expected rate for 2012 : 250 GEM/Year 7/12/2011Rui De Oliveira

No spacers in active area Assembly time ½ hour for 10cm x 10cm detector (1 technician) 2 hours for 1m x 0.6m detector (1 technician) No gluing, no soldering Re opening possible GEM exchange possible Frame less than 10mm Final Gas test with detector assembled New GEM stretching method (NS2) 7/12/20118Rui De Oliveira

No spacer self stretching structure 7/12/2011Rui De Oliveira9 10 to 15mm Readout connector O-ring GEM attaching structure (4 pieces defining gaps) Drift electrode Free to slide External screws to adjust stretching gluing

7/12/2011Rui De Oliveira10 FRAME GEM HV DIVIDER DRIFT BOARD Screws O-ring HV BNC Connector Gas connectors Read-out connectors R/O Board Bottom Top

7/12/2011Rui De Oliveira11 30cm x 30cm

GEM foil tests in CO 2 have been done by applying HV to each GEM and measuring the current. Nothing suspicious has been found. 7/12/201112Rui De Oliveira

7/12/2011Rui De Oliveira13 GEM1GEM2GEM3 HV GNDDrift 40mm Trimming : 0.1% relative 1mA polarizing 4KV 4W power generation Resistor are trimmed for 2 applications: 3/2/2/2 gaps 3/1/2/1 gaps 40 CHF/piece for 1 piece 4 CHF/piece for 1000 piece

MicromegasMicromegas 7/12/201114Rui De Oliveira

7/12/ PCB lamination Mesh deposit lamination development Rui De Oliveira Micromegas

Atlas CSC replacement project 7/12/2011Rui De Oliveira16 MPGD Vs Wire chambers -Faster -no need for fancy gases -lower cost -robust 1.2m x 0.6m

Resistive Bulk MicroMegas 7/12/2011Rui De Oliveira17

7/12/2011 Rui De Oliveira 18 Resistive strip process Photoimageable coverlay technique -less accurate, lower homogeneity -cracks between coverlay and resistive material trapping chemistry -Resistor adhesion problems PCB Full PCB technique -Better resistor uniformity -Easy to clean -Thermally robust

7/12/2011Rui De Oliveira19

Spark signal 7/12/2011Rui De Oliveira20 15us No protections needed for the amplifiers Time 0.35V V on 50Ohms

7/12/2011Rui De Oliveira21 Atlas CSC replacement project Double sided Board Res strip depositing Bulking TestTest before closingClosing

7/12/201122Rui De Oliveira 5 Bulks have been produced -1Standard Bulk (S1) -No production problems -Detector works -3 Resistive Bulk R1 to R3 (coverlay) -1 good piece (R2) Leakage current  -2 are bad due to high leakage current -1 Resistive Bulk R4 (full PCB) -Immediately good at HV test -under test We have removed the meshes for expertise of R1 and R3 Atlas CSC replacement project

7/12/2011Rui De Oliveira23 R1 Perfect strips No visible grooves Absolutely flat Micro grooves between Resistor and Coverlay, Probably trapping some Residues of chemistry coverlay Resistor Dark color due to KmnO4 Cleaning

7/12/2011Rui De Oliveira24 Correct strips No visible problem But the strips are not flat Due to over cleaning R3 Clear resistor delamination due to Coverlay preparation and shorter Thermal treatment

7/12/2011Rui De Oliveira25 X/Y read-out U/V/W read-out

7/12/2011 Rui De Oliveira26 PCB Resistive Strip 1MOhms for 1cm Copper Strip isolated +500V Embedded resistor GND Grounded Mesh

Embedded resistive protection 7/12/2011Rui De Oliveira 27 Read-out strip Embedded Resistor Resistive material (pads down to 2mm x 0.3mm ) 50 to 75um

Resistive MSGCResistive MSGC work done in collaboration with Vladimir Peskov 7/12/201128Rui De Oliveira

7/12/2011Rui De Oliveira29 Readout lines drift -600v0V Resistive linesCoverlay

a) Multilayer PCB with a Cu layer on the top and one layer of readout strips on the bottom, 1mm pitch Upper Cu layer etching The grooves were then filled with resistive paste (ELECTRA Polymers Removal of the Cu v v v Filling with Coverlay b) c) d) e) Microdot detector manufacturing steps v Resistive anode dots 0.1mm diameterResistive cathode strips Readout strips 1mm0.1mm 7/12/201130Rui De Oliveira

A magnified photo of Microdot detector Anode Dots Resistive cathode strips 7/12/201131Rui De Oliveira 1mm 0.1mm 0.7mm 0.5mm 0.3mm

Gain plots Gas gain vs. the voltage of R-Microdot measured in Ne and Ne+1.5%CH 4 with alpha particles (filled triangles and squares) and with 55 Fe (empty triangles and squares). 7/12/201132Rui De Oliveira

Gain (triangles) dependence on voltage applied to R-Microdot measured in Ar (blue symbols) and Ar+1.6%CH 4 (red symbols) and in Ar+9%CO 2. Filled triangles and squares -measurements performed with alpha particles, open symbols - 55 Fe. SQ streamers 7/12/201133Rui De Oliveira

GEM single mask process is stable Ramp up the production Increase the size to 2m x 0.6m Reduce the prices Large Protected Micromegas seems OK Produce 4 2D detector end of January Resistive MSGC seems attractive but: Needs more measurements Needs more understanding Conclusions and next steps 7/12/201134Rui De Oliveira

Thank you 7/12/2011Rui De Oliveira35 GEM: double or single mask 1 to 4 GEMS Read-out: 1D, 2D,3D,Pads, Pixels Compatible whith SRS electronics Gas connection Options: Honey-comb structure Built in Resistive protections HV divider Kit or assembled Bulk Micromegas Read-out: 1D, 2D,3D,Pads, Pixels Compatible whith SRS electronics Gas connection Options: Honey-comb structure Resitive protection Resitive sharing layers Kit or assembled

Voltage-Current Characteristic of the DC Electrical Discharge Gas Discharge Physics, Yuri P. Raizer