1. Edda Gschwendtner1 Status of the TPG B. Bene, A. Blondel, E. Gschwendtner, J.-P. Richeux, R. Sandstrom, O. Voloshyn Universite de Geneve S. Giani, J.-C. Legrand, R. de Oliveira, L. Ropelewski, F. Sauli, M. Van Stenis CERN, Geneva M.G. Catanesi, E. Radicioni INFN, sezioni di Bari V. Ableev, U. Gastaldi, M. Lollo, M. Rigato, P. Temnikov INFN-LNL, Legnaro F. Abrosino, G. Chiefari, M. Napolitano, V. Palladino, L. Roscilli, G. Saracino Universita e sezioni INFN, Napoli M. Apollonio, P. Chimenti, G. Giannini Universita e sezione INFN, Trieste

2. Edda Gschwendtner2 TPG project TPC GEM hexaboard electronics mechanics Newly fabricated GEMs Hexaboard Mechanics Modifications Electronics  Preamps  FADCs HARP TPC Software

3. Edda Gschwendtner3 TPC The test-bed: available infrastructure from the HARP experiment  Beam area  Solenoid  Field-cage  Gas  Electronics  DAQ 2.2m long solenoid, 0.7T field.  <1% disuniformity over 1.5m 80cm diameter field-cage, 1.5m long

4. Edda Gschwendtner4 Modifications from HARP TPC to MICE TPC removal of the inner field cage installation of an adapter flange for hosting the TPG head modified end-plate with holders of X-ray sources

5. Edda Gschwendtner5 In the end, the test should provide simultaneously 1.Many longitudinal tracks (as in MICE) 2.With Kr in the gas, a flow of low energy photons 3.With calibration sources in the end-plates a first example of the calibration system for MICE and flows of photons of various energies (from few KeV to MeV) Altogether a demonstration very near the MICE conditions.

6. Edda Gschwendtner6 GEMs 6 GEM foils 6 support rings Assembly and certifying procedure:  HV tests both on raw GEMs and supports  Glue 1 GEM to 1 support  HV test on glued GEMs  Solder resistors  HV test again

7. Edda Gschwendtner7 GEMs and supports 3 circular GEM supports, with spacers and space provided for resistor chains GEM being stretched before gluing on support. Following previous experiences (i.e. COMPASS), the GEMs are divided in 8 sectors, powered independently.

8. Edda Gschwendtner8 GEM HV test Newly designed probe holder

9. Edda Gschwendtner9 GEM glued on support GEM completed with support and resistors for the voltage divider

10. Edda Gschwendtner10 Hexaboard First hexaboard is finished. Delivered on time but unusable for full test.  Damaged at last production step (pressing/gluing) The hexaboard has been characterized with measurements of strip capacitance Maybe usable for minor measurements, to be verified within a few days. 3 hexaboards are ordered  One will possibly be finished for test-beam measurements now!

11. Edda Gschwendtner11 Hexaboard: active surface Layer M Layer N Layer O Connector 1 1 36 1

12. Edda Gschwendtner12 Hexapads & strips Active surface of a prototype hexaboard 300  m 3 layers of strips running under the pads

13. Edda Gschwendtner13 Hexaboard back (connectors) side Mechanical support structure Prototype hexaboard glued to a support and seen from the connectors side.

14. Edda Gschwendtner14 1 st Hexaboard prototype characterization Capacitance between neighbouring strips are measured for the 3 layers. Typically good values are in the 10pF range. A short-circuit was verified with an ohmmeter… Extended areas in short and some strips with capacitance higher than normal, but overall shape of the plot is right  connections inside the Hexa are not just random

15. Edda Gschwendtner15 TPG head assembly and location of cables Design of the complete assembly of the TPG head, with HV guard ring: field-defining ring to be matched to the corresponding strip on the field- cage 3 GEM supports Hexaboard and its support Main flange with feeds for HV and gas Study of signal routing from the hexaboard to the preamplifier boards via flat cables. Similar to final MICE setup (RF shielding is here missing, not necessary for test beam).

16. Edda Gschwendtner16 Electronics 16 strips flexi-cables 48 channels preamp board Pico-coax bundle 2 x 24 channels to FADC Pico-coax bundle Actions:  Inverted polarity at FADCs: hardware modification, simple but lengthy  Measure gain curves for preamplifiers

17. Edda Gschwendtner17 Software DAQ  HARP, done Reconstruction  geometry and unpacking  Modify clustering First in planes Then in pads Pattern Recognition & Fit  Use same software as for HARP

18. Edda Gschwendtner18 Plans: first stage All components are ready. NOW detector is being assembled. Test of TPG head in small volume  Assemble hexaboard, 3 GEMs  Gas-piping... Ar/CO2 80/20  Assemble TPG head and close with 5cm field-cage  Instrument detector  X-ray measurements  Possibly tracks, but no magnetic field. TPG head can be tested without waiting 2 days for gas flushing or purging in the big field cage Good test already for many parameters relevant to MICE

19. Edda Gschwendtner19 Plans: second stage Mount into HARP TPC only after TPG head fully commissioned  First gas: Ar/CH4 91/9  Present time window for measurements with magnetic field (X-rays, cosmics, parasitic beam), is until 15.11  Longer period maybe possible, to be seen with PS coordination Winter shutdown of the CERN accelerator complex lasts till next spring.  Resuming operation in April.  Complete characterization of the detector.