1 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste THGEM: TRIESTE LAB. EQUIPMENT AND CONTACTS WITH POSSIBLE PRODUCER Introduction THGEM prototypes from ELTOS Equipping the Trieste Laboratory Test boxes Home made amperometers Fulvio Tessarotto

2 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Introduction The development of MPGD-based photon detectors is considered to be very important by Trieste, Turin and others in the COMPASS RICH group We believe there is a brilliant future for gaseous PD’s To start with, THGEM have been selected for this investigation First studies in 2007: Elena Rocco in MPGD lab at CERN Elena’s activity will continue for 2008, and will be complemented by some work at Trieste home laboratory

3 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste The aim of this presentation is to give informations about two items: First contacts with a possible THGEM producer Activity to equip our laboratory in Trieste for THGEM tests People involved for 2008: Jaroslav Polak (PHD, ~100%) Gabriele Giacomini (postdoc, ~100%) Giorgio Menon (~50%) Fulvio Tessarotto (~50%) We plan to provide updates whenever meaningful Introduction

4 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Production of THGEM prototypes Following indications from Rui de Oliveira we contacted an Italian producer: ELTOS S.p.A. (Arezzo, Tuscany) They have wide experience in production of pcb’s of all kinds ~90 workers, high tech equipments We noticed: modern work organization willingness to produce special pieces understanding of our goals

5 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Production of THGEM prototypes Small diameter holes need high rotation speed of the driller: the multi-spindle machines at ELTOS can reach turns/min, allowing hole diameters as narrow as 150 μm. Nominal drilling tolerance: μm POSALUX ULTRASPEED 6000LZ 6-spindle-roboter Estimated cost for large number of holes: ~ 1 euro per 1000 holes

6 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste THGEM prototype geometry Size of active area: 30mm x 30 mm Thickness: 0.4 mm Holes diameter: 0.4 mm Pitch: 0.8 mm diameters Material: R-1566 Panasonic (halogen free, anti CAF) Cu thickness: 35 μm

7 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste THGEM prototypes we ordered We ordered 6 identical pieces for each prototype group, 2 groups without holes for reference measurements and 13 groups with different production characteristics: 1)Single drilling, no etching 2)Double drilling: 0.4 mm mm diam. on one side only 3)Double drilling: 0.4 mm mm 4)Double drilling: 0.4 mm mm 5)Triple drilling 0.4 mm mm mm on the other side too 6)Drilling + etching mm 7)Drilling + etching mm 8)Drilling + etching mm 9)Same as 8) with different material (Isola PLC370 HR) 10)Drilling + etching mm 11)Drilling + laser photolytic imaging + etching mm 12)Drilling + laser photolytic imaging + etching mm 13)Drilling + global etching (no protection) mm

8 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Summary table Nam eDrilling 0.4 mmRim 1 (μm)Rim 2 (μm)rim productionmaterial M1Y00NOPanasonic M2Y250DrillingPanasonic M3Y500DrillingPanasonic M4Y1000DrillingPanasonic M5Y50 Two Sides DrillingPanasonic RNO Panasonic RINO Isola C1Y10 EtchingPanasonic C2Y25 EtchingPanasonic C3Y50 EtchingPanasonic C3IY50 EtchingIsola C4Y100 EtchingPanasonic C5Y10 Laser + EtchingPanasonic C6Y50 Laser + EtchingPanasonic C7Y10 Laser + Global EtchingPanasonic

9 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste THGEM test box

10 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste THGEM test box

11 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste THGEM test box

12 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Signal amplitude spectra  Signals formed on the anode will be read out by ORTEC preamplifier 142PC and Research amplifier ORTEC 450.  The preamp has noise from 300 e- at 0 pF to 450 e- at 100 pF, rise time of 25 ns at 0 pF to 150 ns at 100 pF  The preamp sensitivity is 6.5 V/pC  The amplifier has adjustable gain from 2.5 to 3000, shaping time ~1μs  We will use a 55 Fe source at start, Ar-CO 2 70% - 30% (1 bar)  Gains between 10 and should provide signal amplitudes in the range from 0.2 fC to 200 fC

13 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Multichannel analyzer  Amplified signals will be digitized by CAEN N957 multichannel analyzer.  13 bit ADC, 800 ns conversion time, internal buffer for signals  computer controlled via C++ libreries, 30 Mb/s USB2 transfer rate

14 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Anodic current measurement  For anodic current we will use a KEITHLEY 6485 picommeter (with 10 fA resolution in the lowest range, up to 1000 readings per sec and drivers for control and data storage (LabVIEW, C++, …)  Should not be used above 42 V

15 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Home-made Feedback amperometer This device has been tested to operate at high voltage, powered by batteries. We plan to use one of these for each voltage line  The cost of the pieces for this device is in the order of 100 euros Scheme of principle CMOS Operational Amplifier: AD MΩ feedback resistor (+ parallel capacitor) OEM44 Voltmeter: 4.5 digits We are considering alternatives which would allow automatic recording

16 Fulvio TESSAROTTO CERN, 13/02/ GDD Meeting - Contribution from Trieste Estimate of resolution of the home-made amperometer Using a current generator: 3V battery + 50 GΩ resistor we checked the Keithley response: pA pA Providing the same current to the home-made amperometer we obtained: 61.8 pA pA In both cases no special shielding was provided => We hope to provide < 10 pA resolution in real HV + THGEM set-up