Dimensions of the PDM frame: 167mm x 167mm x 28.7mm

3 different PCBs: First one (EC DYNODE board) allows to reroute half of the dynodes of 1 MAPMT so that they are aligned perpendicularly to the others. It covers the 4 MAPMTs. Second one (EC ANODE board) covers one MAPMT but has dimensions reduced allowing a flex pcb to get out. It is used to collect signal from the anodes and send them to the ASICs. Third one (EC HV board) covers one MAPMT. It welcomes the dynodes and supplies the HV to the EC-dynode board which transmits it to the 4 MAPMTs. Per EC unit: 1 EC-DYNODE board 4 EC-ANODE boards 1 EC-HV boards UV filter MAPMT Flexible pcb toward EC-back HV cables toward HV box 3

MAPMT EC ANODE BOARD EC DYNODE BOARD EC HV BOARD dynode anode EC-ASIC board welcomes ASICs as well as connectors. Data out are then transmitted to the PDM board. Toward PDM board 4

5 The flex and second rigid parts of the EC-anode boards have to go through the mechanical structure to reach the EC-ASIC board. PDM mechanical structure, with cross and hole.

Front view 6.1 mm outer diameter 3.1 mm inner diameter Radius of the corner : R mm Thickness: 1 mm 11 mm 6 mm 17 mm Outer and inner diameters 10 and 6 mm mm 53 mm 51 mm Thickness: 3 mm 9.3 mm 17 mm ~2 mm

EC-dynode needs to be < 55 mm long/large  54.5 mm EC-dynode central hole needs to welcome a screw of mm EC-anode flex and 2 nd rigid parts needs to be < 19 mm large  16 mm EC-anode flex needs to be 4-5 cm long depending on the type The central hole of the mechanical structure can be removed

PCB used to transmit HV signals to the dynodes pins of each MAPMT. Rerouting will have to be done (inside the pcb) for 7 pins (GR and Dy7 to Dy12) of MAPMT 3 For the MAPMTs with no rerouting (1, 2 and 4): all 14 pins (K, GR and Dy1 to Dy12) will be cut and soldered on this pcb For the MAPMT with rerouting (3): the 6 dynodes with lowest voltages and GR will be rerouted, new pins will be soldered on the. These 7 pins and the 7 other ones (Dy1 to Dy6 and K pin) will have extensions added 64 anodes pins going through the pcb (no soldering/connection) Rerouting of 6 HV pins and GR Pins with extensions

Top view 54.5 x 54. mm 1.5 mm thickness (can be reduced to 1.2 mm) 8 layers pcb 3.2 mm hole in the middle 3 areas 16.5 x 2.5 mm added to ease potting spread bottom right MAPMT print corresponds to the one with the pins extended

Top layerLayer 2Layer 3Layer 4 Layer 5Layer 6Layer 7 Bottom layer

EC-ANODE corresponding to the MAPMT with rerouted pins at the level of the EC-dynode board. Bigger holes because of extensions Same PCBs (holes for dynodes are not represented) Extensions Areas gained for flexes 12

Allows the routing of the 64 signals toward the connector. Choice of the connector is the critical part. It shouldn’t be too high, too large or too long but has to allow a feasible routing. 13 Flexible pcb Rigid pcb As long as needed connector 23.7 mm ~ 24 mm < 19 cm

2 types of pcbs are foreseen: 1 with a straight flexible part 1 with a curved flexible part similar routing same orientation One with a connector on top layer, the other with the connector on bottom layer Easier assembly 14 CONNECTORCONNECTOR connector CONNECTORCONNECTOR

First rigid: 24 x 23.7 x 1.5 mm Flex: 16 x 50 x ? mm Second rigid: 16 x 55 x 1.5 mm Rigid parts thickness can be reduced to 1.2 mm Rigid parts: 6 layers pcb Flex: 4 layers pcb Holes for the 14 extensions coming from the EC- dynode: 2 mm large.

Top layer (gnd) Layer 2 Layer 3

Layer 4 Layer 5 Bottom layer (gnd)

Top layer (gnd) Layer 2 Layer 3

Layer 4 Layer 5Bottom layer (gnd)

See Andreas Ebersoldt’s review

MAPMT Screws Column 2 options to fixe the EC front to the PDM mechanical structure: 2 screws and a column (colonnette in French) in between 1 screw long enough (~ 20 mm) In both options the initial central column would be removed. This would ease the assembly and potting of the EC front by postponing the fixation of it on the mechanical structure after the potting. But this central column is part of the initial design which stiffness was proved… Screws would have 2.5 or 3 mm diameter.

MAPMT EC-dynode (1.5 mm) EC-anode (1.5 mm) EC-HV (1.5 mm) 2.5 mm ~ 3 mm 1mm (7) Added pins, black plastic is 2.5 mm high Extensions of the pins Soldering (0.5 mm) 11 mm 8.5 mm 6.5 mm NB: PCBs thickness could be reduced to 1.2 mm MAPMT

EC-dynode (1.5 mm) EC-anode (1.5 mm) EC-HV (1.5 mm) Soldering (0.5 mm) 1.Added pins are soldered to the EC-dynode 2.MAPMT dynodes cut and soldered to the EC-dynode 3.Extensions added to the 14 HV pins coming out of the EC-dynode 4.Anode pins cut (if needed) and soldered to the EC-anode 5.Extensions pins cut and soldered to the EC-HV

25 R11265-M64 MAPMT from Hamamatsu. – 64 channels (Anodes) – 12 Dynodes (Dy1 – Dy12), 1 cathode (K) and 1 Guard Ring (GR) It is a photo-detector used to sense the UV photons arriving through the lenses. Each one should be equipped with a UV filter bonded with an optical glue

Potting must surround the 3 pcbs of the EC- front and the MAPMTs but shouldn’t cover the front of the filters. Potting area Front part of the filters. They must not be covered with potting. Cables going out of the potting MAPMT