1. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Region 2 Drift Chambers Status Report Qweak Collaboration Meeting October 2005

2. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Prototype I 40cm X 40cm 32 20 m m Gold-plated Tungsten Sense Wires 33 100 m m Gold-plated Beryllium-copper Wires

3. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Prototype I Test Setup

4. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Hurdles Jumped TDC readout using MIDAS DAQ “Feedback” from TDC ribbon cables to the chamber wires caused oscillations at ~22MHz. - Tried shielding the ribbon cables (no luck) - installed filter capacitors on the amplifier input (allowed us to take data but reduced amplifier sensitivity) - Wrapped the chamber with Aluminized mylar (Now operating without filter capacitors. Aluminum shield reduces feedback to below 30mV Threshold level) Noise when DAQ running - Raised threshold to 50mV level

5. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Prototype I Tests 10% CO 2 90% argon gas Nanometrics N-277 Amplifier/Discriminator cards Threshold set at 1.5 m amp (50mV) Scintillators above and below chamber Efficiency = (# events with at least one hit)/(# 3-fold scint. triggers)

6. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Cathode at –2000V

7. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Singles Rate

8. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Garfield Equipotential Lines (1800V)

9. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Garfield electron arrival times (1800V)

10. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 # of hits/event Events Prototype I

11. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 hits

12. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 hits

13. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05

14. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Continuing Tests Voltage studies (Cathode/Field) to obtain optimum drift velocity and efficiency Garfield simulations Different gases (Argon/CO 2 /CF 4 )(Argon/Ethane)? Mapping of active area to check uniformity

15. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Proposed New chamber

16. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05

17. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 New chamber

18. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Design Parameters Four chambers with six planes each Wire pitch 4.6 mm 20 m m gold-plated Tungsten sense wires 75 m m gold-plated Be-Cu field wires 1664 electronics channels Nanometrics preamp/descriminators 100 x 16 channels/board = ~$35k

19. N. Morgan, Virginia Tech Qweak meeting,Oct ‘05 Plans for 2006 Build and test a chamber with the final dimensions xuv sense planes four cathode planes 208 electronics channels