What we did up to now:

1. What we did up to now: Summary of the measurements performed up to now with the gas setup built for the THGEMs coated with the CsI. • Photocurrent measurements (Leszek’s chamber) with several gas mixtures (Ne, Ar, CH4, NeCH4 X/100-X, ArCH4 X/100-X, ArCO2 70/30) at different pressures (i.e. atm pressure, 0.2 bar, 30 mbar) for a dummy THGEM coated with CsI and with a dummy THGEM as a drift (see Jarda’s presentation GDD 32 meeting); • Quick characterization (drift and voltage scans) for a double structure THGEM (C7 type: d=0.4 mm, p=0.8 mm, t=0.4 mm, rim=0.01 mm) used as a single structure with 55Fe source flushing the gas at atmospheric pressure and with several gas mixtures (NeCH4 90/10, CF4, ArCH4 X/100-X, ArCO2 70/30); • Optimization of the voltage on the double THGEM structure for few gas mixtures at atmospheric pressure with 55Fe source; • Drift scan with the UV light (Oriel Lamp) on the double THGEM used as a single and as a double structure just with the Ar/CO2 gas mixture (70/30); • Single Photon spectrum acquisition and estimation of the rate of the photons from the current measured onto the anode.

2. Same setup, several & different purposes Setup for photocurrent measurements and optimization of performance for the double THGEM structure with the iron source Quartz window of the double THGEM chamber (type C7) Hidden N2 exhaust Leszek’s chamber Dummy/dummy picoammeters Oriel Lamp N2 inlet Double THGEM C7 Gas mixer 55Fe Avantes – UV lamp Filter 3.0 OD Setup for UV light meas. with the double THGEM structure Filter 0.5 OD Three positions of the shutter: 1.completly open, 2.closed (some internal reflections), 3.Open + filter 3.0 OD Narrow Filter

3. drift = wires Some examples about performed meas. d=4.5 mm Collection efficiency of electron from CsI Transfer scan of the double THGEM with Iron source THGEM 1 d=1.6 mm THGEM 2 d=1.6 mm anode Single Photon spectrum THGEM: C7 d=0.4 mm pitch =0.8 mm t=0.4 mm rim=0.01 mm