1. Chamber PCB s, FEB s, Cooling, HV/LV Distribution 1)PCB designs-track widths, track to track distances … 2) Double sided and Multi layer, modular approach. 3) Resistors for protection against possible sparks. 4) Orientation of FEB s, Scheme, Cooling 5) HV/LV distribution- No of channels, Modules, cost

2. Prototype PCBs No of pads- 256, Pad sizes-8*3.4 sq mm Readout area-97*85 Sq mm. Read by 2 FEBs each with 128 channels. 2 types of pad sizes tried. Both Staggered. Double sided PCB Track widths -6mil Track- track – 6 mil to 15mil. Resistors added later (0603) Top copper 256 tracks - all on bottom copper For previous test beams vias from- top to bottom copper

3. For next Test beam Resistors -0402 3 and 4 sq mm pads. Not staggered. Track lengths are long. 4 mil tracks. Track- track 4 /6 mil spacing Cross talk??? Multi layer with GND planes??? 512 pads- to be read by 4 FEBs each 128 channels Double sided PCB- all 512 tracks on bottom copper only Bottom copper Top copper Pad area-67*73 Sq mm for 3mm. For 4mm - 88*97 sq mm

4. 4 layer PCB with GND Plane Top copper Inner 1 Inner 2 Bottom copper Connectors for FEBs Connector with resistors Type 1 GND Plane GND plane GND Plane

5. 4 layer PCB with GND tracks Bottom copper Inner 1 Every track is in between 2 GND tracks. in case of type2 Too many tracks to draw. Easy to draw the GND planes in case of type1. Removal of planes is also easier Track lengths are still very long due to connectors for both cases. Type-2 Top and Inner-2 not shown.

6. Modular approach Inner 1Inner-2Bottom Copper 2.6 Sq mm Pads 32*8 matrix. 256 pads Single 300 pin Connector. Reads 2 n - XYTERS. Top copper Blind vias from inner layers( blue) Blind vias (red ) to inner layer 2.6 mm square pads  Pads arranged in one block of 32*8=256.  Connected to 300 pin connector.  Tracks - shorter and not closer.  can be easily duplicated for bigger sizes.  4 such blocks for GEM of 10cm * 10 cm.  Each block read by 1 FEB with 2 n-XYTERs  No resistors could be added so far.  FEBs can be mounted horizontal or vertical For STAR PMD For ALICE PMD

7. Prototype design Inner1 Inner2 Bottom copper Top copper 4 connectors. Each reads 2 N-XYTERS. 44 spare pins on the connector.

8. FEB--Probable scheme?? 64 channel chip-- No of Pin outs 125-150? For inputs- 64 For I2c - 6 For CLK - 6 For SDA, SCl - 2 I2C Reset - 2 Reset 2 DATA (diffl) --- 18 ( 16 for digital, 2 analog) Total -100 PLUS Bias,GND, other control inputs -25 to 50 ?? Consider BGA144(1,27mm pitch) / SQFP148(10*14) with 148 pin count and if we arrange-see the board size-10cm*3.2cm BGA-144 ADC 300 Pin CON SQFP148 ADC ROC CON

9. Cooling Issues  FEB with one NXYTER draws 1.5A @5V.(with regulators)  For a 2 chip FEB, Current drawn is expected to be 3A minimum. Power= 15Watts. With 3.3V it is 10 Watts.  With 4 such FEBs, each reading a zone with 1K pads, the power dissipation is 40 Watts on an area of 10(cm) * 10 (cm).  Same as power dissipated on one ALICE-PMD module (4608 cells).  Each FEB with 2/4 n –XYTERS needs cooling. To be taken care while designing the FEB.

10. Detector specifications Detector active area= 20 sq met. GEM PCB dimensions= 30x30Cm. No Of GEMS required =20 ÷0.3x0.3= 222.2= 222 Total number of GEMs required = 222x3= 666 (for triple GEM). 9k pads on one chamber PCB (30cm by 30 cm) For 500,000 we need 56 Nos, each for chamber and drift PCBs (min). HV HV channels required for GEM PCBs = 222 ( one for each triple GEM) HV specification = 3 to 5 KV/1mA /5Watts. CAEN 1535 board has 24 HV channels. Each = 3.5KV/3mA. SHV /multi pin connectors. CAENA1550-5KV/1mA with multi Pin and SHV Can be housed in SY1527. Number of boards required will be = 10 ( 10x24=240 channels). SY 1527 houses 5/10 boards. Need 2/1 Crates. Power consumption= 240x5Watts = 1.2KW Detector, HV

11. FEBs-LV FEB s, ROC s Channels to read= 500,000 One N-XYTER reads =128 channels. FEB with 2 n-XYTERS reads-256 channels No of FEB s Required = 500,000÷256 = 2000 No (512,000 channels). Each ROC can handle = 2 FEBs (512 channels). No Of ROCs required =1000Nos. LV Specifications 2chip Feb With 3.3 v supply the power dissipation =10watts. 2000 FEBs consume =2000x 10Watts =20KW. One ROC need -3.5A @5V ( one FEB connected). With two FEBs it is 4A 1000 ROC s consume = 1000x5Vx4A=20KW. Power consumption expected for 2000FEBs +1000 ROCs = 40KW

12. A3009B -2to 8 V, 9A @5V. Max =45W. Has 12 independent channels. Max 480Watts For 1000 ROCS Need 1000÷12= 84 modules For 2000 FEBSs = 2000÷12= 167 modules. Need 167+84 =251 modules. Separate LV channels for FEB and ROC. Alternately: Reduce LV channels to 168÷2=84 by using LVDB to feed 2 FEBS (from 1 channel) Need 84+84 =168 modules. No of 3009s in one EASY crate =4 (2KW) EASY crates Required = 250÷4=63 or 164 ÷4=41 With 2 channels 3486 has =48V /40A, Power Capacity =5KW 3486 s required = 40KW÷5 = 8Nos. Filter for 3486 =8 Nos. One Branch Controller (A1676A) controls 6 EASY- 3000 Crates. For 63/41 Crates we need = 11 /7 Branch controllers. LV distribution

13. Costs of CAEN-LV/HV modules SY1527 -Universal Crate-- 11K Euro 3486-48V supply- 12K Euro A3000NF-Filter for 3486--- 3.2KEuro A1676- Branch Controller --- 1.4K Euro A3009B--- 2 to 8V supply ----- 7.1K Euro EASY 3000 Crate (for A3009B)---- 2.6K Euro A1535-24 channel HV module---- 4.8K Euro A1550 -24 Channel HV module---------- 5.8K Euro

14. Issues to be taken care  Too many modules and Crates ???  Alternate systems from WEINER or ??  Which Detector Control System PVSS or ???  Cooling system - water cooled or air cooled??  FEB PCB vertical type of horizontal type ???  If No regulators on the FEB, any precaution to be taken in DB…..????