1. Proposal for the construction procedures for the NSW chambers Harry van der Graaf, Nikhef Frascati, Nov 29 2012

2. Dear Harry, thanks for your slides. It would nice if you could come to the Frascati meeting and bring your ideas into the discussion. A 15' minute presentation would be very welcome. I would like to limit the time of presentations to leave enough time for discussion. Let me also recall that the purpose of the meeting is to organize the work on mechanical prototypes that would allow us then to take a decision on the assembly procedure based on real objects and not on paper work. It would be great if NIKHEF (with all its experience) could be one of the places where assembly procedures can be developed and engineering prototypes will be built. Time scale is between now and summer 2013. Plus the real work to come later... Cheers Joerg

3. Nikhef will not contribute to the NSW chamber project (for now) Based on experience with MDTs, Honeycomb chambers, Micromegas chambers and GridPix/InGrid/Gossip detectors, we worked out an assembly schema for the NSW chambers I am interested to collaborate with institutes to construct prototypes Who knows what happens next?

4. Essential construction element: the monolayer -sufficiently rigid to be manipulated & stored -(possible) gas tight unit, full HV testable -has precise layer thickness (height) of 10 mm, +/- 3 μm -does not deform under gas pressure NSW chambers are stacked monolayers

5. Any table Spacers on Cathode Boards (CBs) -non-precision spacer: -height: 9.8 mm (mold injection) for 10 mm drift gap -dia. 5 mm -hollow cylinder: wall thickness 0.8 mm -Spacer pitch: Tapered, hex or square pattern, pitch 100 – 200 mm -Cathode Boards (CB): single sided Cu, segmented Thickness variations allowed -Tool (template) for rapid positioning of spacers -Apply UV curing glue (R&D: check ageing effects)

6. Any table Spacer Positioning Tool UV-LED Spring (cushion) O-ring CB

7. Any table Micromegas on Cathode Board (CB)

8. any table Resistive silk screen printing on Anode Board (AB) Photoresist Avalanche Gap Pillars + Spacer Pedestals AB + photoresist pillars

9. Preparation (in design) of the Anode Boards (ABs): AB (0.8 – 1.0 mm) Micromegas Micromegas support (photo resist) Pedestal for spacer dia. 5 mm

10. Granite flat table Construction of monolayers CB + spacers + micromegas + edge gas seals AB + pillars + pedestals straight edge + CB egg-suckers

11. Granite flat table Construction of monolayers Gauge blocks: define thickness monolayer (σ < 5 μm) Monolayers (gas tight) can be made fully operational and tested Gas seals at edges: undersized, glue sealed

12. Granite flat table Construction of bi-layers Assembly of: -two monolayers -spacer: -could be interconnected spacers (same X,Y position as in monolayer) -could be (machined) honeycomb -could be polyester wire (1 mm dia). -Height verification after assembly CB AB CB

13. Granite flat table Construction of quadlayers Assembly of: -two duallayers -spacer: -could be interconnected spacers -could be (machined) honeycomb -could be plastic wire Height verification after assembly

14. Spacer (stiffback, cross plate, longbeam, InPlane Rasnik systems) Quad layer Granite flat table Construction of chamber stations Assembly of: -two quadlayers -spacer: -made from G10 plates, bars, profiles -has 3 or more external temporally references: only precise in length (height). -includes Rasnik InPlane system (2 cams, 4 diff. plates, 4 light sources) readout during construction (calibration: ‘straight’ values).

15. USB Pixel CMOS chip (taken out 10 $ webcam) Diffraction Plate lasers (out of pointer!)Readout USB webcam: any processor

16. Quad layer Granite flat table Construction of chamber stations: fixing the 2 nd quad layer Quad layer Spacer (stiffback, cross plate, longbeam, InPlane Rasnik systems)

17. Alignment of Anode Boards (AB’s): Idea of Saclay: Rasnik code in Cu at upper and lower edges

18. Granite flat table Alignment of Micromegas PCB (MB): - Integrate Rasnik mask in CU of all MBs: -Record (X,Y) positions in each corner (4x) by means of 4 cam’s -Also Z values can be measured (quality control!)

19. Granite flat table Large monolayers (combination of 2 or more ABs): Glue strip ends together with (permanent) aux. joint plate interconnect (wire bond) strips Use filler spacer while applying CB+pillars filler