Gas Electron Multiplier A Gas Electron Multiplier F

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Gas Electron Multiplier A Gas Electron Multiplier (F. Sauli, NIM A 386 531 1997)

Gas Electron Multiplier A Gas Electron Multiplier (F. Sauli, NIM A 386 531 1997) is made by 50 m thick kapton foil, copper clad on each side and perforated by an high surface-density of bi-conical channels; 70 µm 140 µm 50 µm 31 x 31 cm 2 F. Murtas LUMI GEM 1

Gas Electron Multiplier Filed lines By applying a potential difference between the two copper

Gas Electron Multiplier Filed lines By applying a potential difference between the two copper sides an electric field as high as 100 k. V/cm is produced in the holes acting as multiplication channels. Potential difference ranging between 400 - 500 V F. Murtas LUMI GEM conversion and drift amplification transfer 2

Triple GEM geometries Gain ~20 ~20 ~8000 F. Murtas LUMI GEM 3

Triple GEM geometries Gain ~20 ~20 ~8000 F. Murtas LUMI GEM 3

A Triple GEM luminometer 10 cm 2. 4 cm 64 pads 10 cm A

A Triple GEM luminometer 10 cm 2. 4 cm 64 pads 10 cm A triple GEM 10 x 10 cm 2 has been built with a 64 pixel 3 x 3 mm 2 The read out has been realized using 8 chip ASDQ (8 channel each) Actually non more than 64 channel readout is possible; but we are working on implementation of a new chip IDEAS with 64 ch each F. Murtas LUMI GEM 4

Movie on chamber This movie has been realized during the readout debug. F. Murtas

Movie on chamber This movie has been realized during the readout debug. F. Murtas LUMI GEM 5

A Triple GEM luminometer The chamber has been placed on BTF for tests with

A Triple GEM luminometer The chamber has been placed on BTF for tests with electrons and photons The chamber is readout with a 64 ch scaler with a time gate of 200 ns F. Murtas LUMI GEM 6

Electron Beam 1 electron 1 2 electrons 3 Hit Multeplicity Raw Data !!! Beam

Electron Beam 1 electron 1 2 electrons 3 Hit Multeplicity Raw Data !!! Beam Spot F. Murtas LUMI GEM 7

Analysis number of electrons tagging electron efficiency 80 % (due to leakage) spatial resolution

Analysis number of electrons tagging electron efficiency 80 % (due to leakage) spatial resolution sx=sy= 3. 3 mm including beam spread F. Murtas LUMI GEM 8

Efficiency with electron Measurements with an LHCb Chamber (same structure) at BTF on September

Efficiency with electron Measurements with an LHCb Chamber (same structure) at BTF on September working range F. Murtas LUMI GEM 9

Working in progress Next days measurements with BTF photons After that possible measurement on

Working in progress Next days measurements with BTF photons After that possible measurement on Dafne F. Murtas LUMI GEM 10

Thecnical slides F. Murtas LUMI GEM 11

Thecnical slides F. Murtas LUMI GEM 11

30 -1 -2007 ore 9: 15 run 1048 “linea fotoni” run su elettroni F.

30 -1 -2007 ore 9: 15 run 1048 “linea fotoni” run su elettroni F. Murtas LUMI GEM 12

30 -1 -2007 ore 9: 15 Pedestal run 1049 F. Murtas LUMI GEM 13

30 -1 -2007 ore 9: 15 Pedestal run 1049 F. Murtas LUMI GEM 13

30 -1 -2007 ore 9: 25 run 1052 fascio 2 -3 elettroni F. Murtas

30 -1 -2007 ore 9: 25 run 1052 fascio 2 -3 elettroni F. Murtas LUMI GEM 14

2 run su elettroni 1058 e 1059 picco del pedestals F. Murtas LUMI GEM

2 run su elettroni 1058 e 1059 picco del pedestals F. Murtas LUMI GEM 15