1. Proposal for LST-based IFR barrel upgrade Roberto Calabrese Ferrara University Workshop on IFR replacement, SLAC, 11/14/2002

2. Outline General Overview Layout geometry Performance Readout methodology Electronics Gas, HV, DAQ Costs Other presentations

3. General overview The entire project is driven by the allowed space The intrinsic efficiency of a standard LST tube is about 90%. This is due to dead spaces in the LST tubes. Efficiency is too low for our purposes. Not enough space to put 2 standard layers.

4. Possibilities to improve efficiency (given the allowed space) Option 1: single-layer with a large cell (19x17 mm) Readout of x and y coordinates from outside strips

5. Possibilities to improve efficiency Option 2: double-layer with a small cell (9x8mm) Readout of x coordinate from wire and y coordinate from outside strips

6. Possibilities to improve efficiency Option 3: modified double-layer with a small cell (9x8mm) Readout of x and y coordinates from outside strips

7. Detector layout: segmentation of a detector layer Z strip readout Layer of LST Ф strip readout Z strip signal collection PCB Ф strip signal collection PCB (a similar one in the opposite corner) PCB for cable connectors Servizio Elettronico INFN Ferrara

8. Detector layout: details of strip signal collection PCB Servizio Meccanico INFN Ferrara

9. Performance Expected efficiency about 96% Position resolutionbetter than 3 mm (z) for standard LSTbetter than 9 mm (  ) We do not need such a resolution and we can increase the strip width, thus decreasing the number of channels (  MC simulation)

10. Detector layout: questions How many strips?  resolution, cost, space How many chambers/layer ?  installation, cost

11. Detector layout: answer to the questions We are considering 4 cm z-strips and 4.3 cm  -strips (2  -strips (along the wire)/LST tube)  96 z-strips for each layer, total 6912 z-strips  74  -strips for the outer layer, total 4572  -strips  About 11500 channels of electronics 2 chambers/layer (remove only one corner block at the time), but the number of z-strips doubles (more cables, but same number of electronics channels) or we need to decouple z-strips from the chambers

12. Readout methodology Only digital readout of strips Time measurements could be implemented:  OR of 16 discriminated pulses  Time resolution about 16 ns ( using BaBar reference clock)  Implemented with FPGA

13. Electronics FEC gain depends on the shape of the signal  FEC ampli cannot be used Existing FEC: to be modified if we want to use them (when?)  the baseline is to use new electronics

14. Front end module design : block diagram of the NEW 96 channel (1 view of 1 layer) FEC 96x Amplifier-Discriminator 11us Digital OneShot Shift/Load Ck_Chain Data Out SHIFT REGISTER 96 x Threshold 12us Digital OneShot 11us Digital OneShot 12us Digital OneShot Shift/Load To the Active Patch Panel ahead of the FIFO Board 6 x Implemented in a single high performance FPGA (Field Programmable Gate Array) Cost per channel inclusive of: -components -PCB -crate&power supply 10 € / channel Servizio Elettronico INFN Ferrara

15. Front end module design : schematic of the front end based on Off-The-Shelf components Power dissipation: 250mW Servizio Elettronico INFN Ferrara

16. Front end module design : analog simulations, effect of strip capacitance and impedance Simulation of the amplifier/discriminator output from a 4pC input signal (0.1mA * 40ns) Comparator threshold = 50mV dielectric thickness 0.75mm a) dielectric FOAM (ε r =1) b) dielectric PTE (ε r =3.3) c) dielectric FR4 (ε r =4.8) a) b) c) Servizio Elettronico INFN Ferrara

17. Gas system mass flow control system main gas transport pipe system (existing) final gas distribution and bubbling system. We assume all the tubes in a layer with a single in/out Safe gas mixture, like Ar/Iso/CO 2 (2.5/9.5/88) (SLD)

18. HV, DAQ Each tube has a separate HV connection ( 2 for a double layer tube)  Possibility to use a commercial HV system for LST available from CAEN (SY546 mainframe + 12 channel boards A548), 150 $/channel DAQ  No change, all signals are FEC-like

19. Costs: assumptions double layer LST with 8mm cells; each layer with a separate HV; each ground returning separately through a measuring resistor 96 strips (40 mm strips) in the z direction; 2 strips per LST in the  direction 2 chambers/layer (double the number of z strips signals) 12 active layers

20. Costs (I) Tubes:  30 K$ (setup)  450 K$ ( about 200 $/tube x 2280 double layer tubes) Total cost tubes 480K$ (using single layer tube this cost would be about 300K$) Strip readout planes 240 m 2 /layer x 6 layers x 50 $/m 2 = 72 K$ Signal collection (PCB’s) inside iron 18 K$ Total cost readout planes 90 K$ Grand total chambers 570K$ (double layers); 390K$ (single layers)

21. Total cost of signal flat cables 146 K$ (outside iron) 15 K$ (inside iron) Total cost of signal flat cable connectors 28 K$ Total cost of electronics 115 K$ Service panels 4 K$ Total cost of LV ground wire 5 K$ Total cost of LV plugs 4K$ TDC system 20K$ (optional) Total electronics + cables 322 K$ (maximum); 171 K$ (minimum) Costs (II)

22. Costs (III) Total cost of HV wire 23 K$ Total cost of HV banana plugs 9 K$ Total cost of HV power supply+distributors 170 K$ Total cost of mass flow control system 11 K$ Total cost bubbling system 4 K$ DAQ, cooling no expected cost Total this page 217 K$ Grand total detector 780 K$  1100 K$

23. Addressing the various issues R&D issues and statusChangguo Lu LST experience and production issuesMario Posocco Installation issuesLivio Piemontese