1. Tracking Session, Groningen, August 30th, 2010 1 News from Krakow on the Forward Tracker J. Smyrski Institute of Physics UJ Model of the tracking stations FT3, FT4 Development of new end plugs for straws

2. Model of FT3 and FT4 FT3 FT4 Dipole magnet beam Main challenge: to place all passive elements including straw end plugs, support frames, electronics and cabling within the foreseen space limited to Δy≤55 mm 12 modules /double layer

3. Side view 0º0º+5º-5º0º0º0º0º+5º-5º0º0º

4. Cabling for one double layer 12x HV cables (weight 3 G/m) 12x signal cables + disc. threshold control + test pulser control (weight 67 G/m) LV supply (U=6V, I=3.6 A) (2x isolated copper lead 3 mm 2 ; weight 53 G/m) U-profile for laying down the cables Total weight of cables for one double layer: 0.6 kG

5. Gas connections gas in out manifold outlet inlet

6. Development of new end plugs for straws (for an easy assembly and for elimination of the grounding spring) Basic functions of end plugs: Gas supply Gas supply Holding the anode wire Holding the anode wire Centering the anode Centering the anode Electrical connection of anode Electrical connection of anode Grounding the cathode Grounding the cathode

7. Wedging anode wire in plastic socket with brass tube Pneumatic hummer Brass tubePVC socket 25 μm tungsten wire 9 20 conical part of tube PVC socket wire

8. Measurement of wire tension Drop of tension due to wedging: Drop of tension due to wedging: from t 0 = 50 G to t 1  (42.9 G, 49.3 G) from t 0 = 50 G to t 1  (42.9 G, 49.3 G) (for 10 stretched wires) (for 10 stretched wires) The tension remained constant The tension remained constant within the measuring accuracy of about 0.5 G during monitoring period of 3 months (observation of signal induced by vibrations of wire in magnetic field; length of wire = 1m)

9. Summary 3-D model of FT3 and FT4 completed 3-D model of FT3 and FT4 completed (at least for the time being); further details and corrections will be introduced after construction of prototype double layer Wedging of anode wires in PVC socket with brass tube works, but the scatter of the wire tension should be reduced Wedging of anode wires in PVC socket with brass tube works, but the scatter of the wire tension should be reduced