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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 1 Edda Gschwendtner TPG project mechanics GEM TPC Modifications Electronics Preamps FADCs 2 HARP TPC Software Software electronics hexaboard Newly fabricated GEMs Hexaboard Mechanics Edda Gschwendtner 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 3 Edda Gschwendtner 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 4 Edda Gschwendtner 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. 5 Edda Gschwendtner 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 6 Edda Gschwendtner 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. 7 Edda Gschwendtner GEM HV test Newly designed probe holder 8 Edda Gschwendtner GEM glued on support GEM completed with support and resistors for the voltage divider 9 Edda Gschwendtner Hexaboard First hexaboard is finished. Delivered on time but unusable for full test. 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 10 Damaged at last production step (pressing/gluing) One will possibly be finished for test-beam measurements now! Edda Gschwendtner Hexaboard: active surface Layer N 36 1 1 36 Connector 36 Layer O 11 1 Layer M Edda Gschwendtner Hexapads & strips •Active surface of a prototype hexaboard 300 mm 3 layers of strips running under the pads 12 Edda Gschwendtner Hexaboard back (connectors) side • Mechanical support structure • Prototype hexaboard glued to a support and seen from the connectors side. 13 Edda Gschwendtner 1st 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… Layer M for shorcut: C==0 90 n:n+1 connector 80 70 60 C [pF] 50 40 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 30 20 10 0 0 100 200 300 400 500 600 -10 14 strip number Edda Gschwendtner 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 fieldcage • 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). 15 Edda Gschwendtner Electronics 16 strips flexi-cables Pico-coax bundle 16 strips 2 x 24 channels to FADC 16 strips Pico-coax bundle 48 channels preamp board Actions: Inverted polarity at FADCs: hardware modification, simple but lengthy Measure gain curves for preamplifiers 16 Edda Gschwendtner Software DAQ HARP, done Reconstruction geometry and unpacking Modify clustering Pattern Recognition & Fit 17 First in planes Then in pads Use same software as for HARP Edda Gschwendtner Plans: first stage 18 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 Edda Gschwendtner 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. 19 Edda Gschwendtner