thgem: trieste lab. equipment and contacts with possible producer

Fulvio TESSAROTTO CERN, 13/02/2008 - GDD Meeting - Contribution from TriesteCERN, 13/02/2008 - GDD Meeting - Contribution from Trieste 11

THGEM:THGEM: TRIESTE LAB. TRIESTE LAB. EQUIPMENT AND CONTACTS EQUIPMENT AND CONTACTS WITH POSSIBLE PRODUCERWITH POSSIBLE PRODUCER

Introduction

THGEM prototypes from ELTOS

Equipping the Trieste Laboratory

Test boxes

Home made amperometers

Fulvio Tessarotto


IntroductionIntroduction

The development of MPGD-based photon detectors is considered to bevery 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 complementedby some work at Trieste home laboratory


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

IntroductionIntroduction


Production of THGEM Production of THGEM prototypesprototypes

Following indications from Rui de Oliveira we contacted an

Italian producer: ELTOS S.p.A. (Arezzo, Tuscany)http://www.eltos.it/en/main/en-main.htm

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

http://www.eltos.it/en/main/en-main.htm


Production of THGEM Production of THGEM prototypesprototypes

Small diameter holes need high rotation speed of the driller: the multi-spindle machines at ELTOS can reach 180000 turns/min,

allowing hole diameters as narrow as 150 μm.

Nominal drilling tolerance: +- 10 μm

POSALUX ULTRASPEED 6000LZ6-spindle-roboter

Estimated cost for large number of holes: ~ 1 euro per 1000 holes


THGEM prototype THGEM prototype geometrygeometry

Size of active area: 30mm x 30 mmThickness: 0.4 mmHoles diameter: 0.4 mmPitch: 0.8 mm diametersMaterial: R-1566 Panasonic(halogen free, anti CAF)Cu thickness: 35 μm


THGEM prototypes we THGEM prototypes we orderedordered

We ordered 6 identical pieces for each prototype group,2 groups without holes for reference measurements and13 groups with different production characteristics:1) Single drilling, no etching2) Double drilling: 0.4 mm + 0.45 mm diam. on one side

only3) Double drilling: 0.4 mm + 0.50 mm4) Double drilling: 0.4 mm + 0.60 mm5) Triple drilling 0.4 mm + 0.50 mm + 0.50 mm on the other

side too6) Drilling + etching 0.010 mm7) Drilling + etching 0.025 mm8) Drilling + etching 0.050 mm9) Same as 8) with different material (Isola PLC370 HR)10) Drilling + etching 0.100 mm11) Drilling + laser photolytic imaging + etching 0.010 mm12) Drilling + laser photolytic imaging + etching 0.050 mm13) Drilling + global etching (no protection) 0.010 mm


Summary tableSummary tableNam

eDrilling 0.4

mm Rim 1 (μm) Rim 2 (μm) rim production materialM1 Y 0 0 NO Panasonic

M2 Y 25 0 Drilling Panasonic



M5 Y 50 50 Two Sides Drilling Panasonic

R NO NO NO NO Panasonic

RI NO NO NO NO Isola

C1 Y 10 10 Etching Panasonic



C3I Y 50 50 Etching Isola


C5 Y 10 10 Laser + Etching Panasonic

C6 Y 50 50 Laser + Etching Panasonic

C7 Y 10 10 Laser + Global Etching Panasonic


THGEM test boxTHGEM test box


Signal amplitude Signal amplitude spectraspectra

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 55Fe source at start, Ar-CO2 70% - 30% (1 bar) Gains between 10 and 10000 should provide signal amplitudes in the range from 0.2 fC to 200 fC


Multichannel analyzerMultichannel analyzer

Amplified signals will be digitized by CAEN N957 multichannel analyzer.13 bit ADC, 800 ns conversion time, internal buffer for 65535 signals computer controlled via C++ libreries, 30 Mb/s USB2 transfer rate


Anodic current Anodic current measurementmeasurement

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


Home-made Feedback Home-made Feedback amperometeramperometer

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 8607

10 MΩ feedback resistor (+ parallel capacitor)

OEM44 Voltmeter: 4.5 digits

We are considering alternatives which would allow automatic recording


Estimate of resolution of Estimate of resolution of the home-made the home-made amperometeramperometer

Using a current generator: 3V battery + 50 GΩ resistor we checked the Keithley response: 61.43 pA +- 0.23 pA

Providing the same current to the home-made amperometer we obtained: 61.8 pA +- 2.7 pA

In both cases no special shielding was provided

=> We hope to provide < 10 pA resolution in real HV + THGEM set-up

thgem: trieste lab. equipment and contacts with possible producer

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