PNPI R&D of the detectors for MUCH E. Chernyshova, V.Evseev, V. Ivanov, A. Khanzadeev, B. Komkov, L. Kudin, V.Nikulin, G. Rybakov, E. Rostchin, V.Samsonov, O.Tarasenkova, S. Volkov A.Khanzadeev_GSI_April 2010

This year our main R&D activity – assembling and testing two prototypes with radioactive sources. One of them – Double TGEM, another one – hybrid MICROMEGAS/GEM Anode structure 2048 pads with hidden contact holes Pad size 1.5x 3 mm 2 Working area 102x109 mm 2 Gap between pads 0.2 mm Preamp to take signals from mesh or TGEM A.Khanzadeev_GSI_April 2010

TGEM1 GG vs. ΔVg (ΔVag=0.28kV, ΔVgc=0.1kV – fixed) Thickness – 0.53 mm, distance between holes – 1.6 mm, hole diam. – o.5 mm, rim diam. – 0.72 mm Ar/CO2/iC4H10 (90/8/2) TGEM1 A.Khanzadeev_GSI_April 2010

TGEM 1 GG vs. ΔVgc (ΔVg=1.1kV, ΔVag=0.7kV – fixed) GG vs. ΔVag (ΔVg=1.11kV, ΔVgc=0.1kV – fixed) A.Khanzadeev_GSI_April 2010 For TGEM1 we can reach Gas Gain up to 12∙10 3 and energy resolution ~40% without visible problems Ar/CO2/iC4H10 (90/8/2)

TGEM2 ΔVag=0.6kV, ΔVgc=0.2kV– fixed A.Khanzadeev_GSI_April 2010 Thickness – 0.95 mm, distance between holes – 1.6 mm, hole diam. – 0.6 mm, rim diam. – 0.79 mm GG vs. ΔVag (ΔVg=1.3kV, ΔVgc=0.1kV – fixed) The same as for TGEM1 for TGEM2 we can reach Gas Gain up to 12∙10 3 and energy resolution fwhm~40% without visible problems Ar/CO2/iC4H10 (90/8/2) TGEM2

Double TGEM1/TGEM2 GG vs. ΔVg1g2 (ΔVag=500V, ΔVg1=800V, ΔVg2=1100V, ΔVcg=50V – fixed) Ar/CO2/iC4H10 (90/8/2) For double TGEM1/TGEM2 we can reach Gas Gain up to 30∙10 3 and energy resolution ~35% without visible problems 1.0 mm 0.5 mm A.Khanzadeev_GSI_April 2010 The best energy resolution reached – 30% (fwhm)

Double TGEM1/TGEM2 He/CF4/iC4H10 (75/23/2) GG vs. Δ Vg1 (ΔVag1=450V, ΔVg1g2=30V, ΔVg2= ΔVgc=0V) GG vs. Δ Vg2 (ΔVg1=750V, ΔVg1g2=450V, ΔVag1=450V, ΔVgc=50V During the test with 55 Fe double TGEM detector showed stable behaviour. Operation of the detector with He based gas mixture allows soft HV regime to get supposed for MUCH electronics value of GG=2∙10 4 A.Khanzadeev_GSI_April 2010

Drawback – to have good collection of primary electrons (shape and resolution of the 55 Fe spectrum are indicators) from cathode-GEM2 gap it was necessary to keep low voltage (about 50 volts per 4 mm). So, in this case we have huge charge collection time. Reason for that is large distance between holes. To solve this problem we have produced new TGEMs having smaller distance between holes. A.Khanzadeev_GSI_April 2010

Double TGEM1/TGEM2 (new TGEMs) Ar/CO2/iC4H10 (90/8/2) GG vs. ΔVg1&ΔVg2 (ΔVg1=ΔVg2) (ΔVag=300V, ΔVg1g2=300V, ΔVcg=800V) GGx10 3 TGEM1, TGEM2 are identical: thickness – 0.53 mm step between holes – 1 mm hole diam.– 0.6 mm rim diam mm volts Resolution, % ΔVg, volts A.Khanzadeev_GSI_April 2010 For new double TGEM1/TGEM2 we can reach Gas Gain up to 30∙10 3 and energy resolution fwhm ~30% without visible problems Gaps: Anode-G1 – 1.5mm G1-G2 – 1.5 mm Cathode-G2 – 4 mm

Ar/CO2/iC4H10 (90/8/2) A.Khanzadeev_GSI_April 2010 Double TGEM1/TGEM2 (new TGEMs) Gas gainX10 3 volts Gas gainX10 3 volts GG vs. ΔVgc (Δ Vg1= Δ Vg2=800V, ΔVag1=300V, ΔVg1g2=300V) GG vs. ΔVag1 (ΔVg1=ΔVg2=800V, ΔVg1g2=300V ΔVgc=800V ) GG vs. ΔVg1g2 (Δ Vg1= Δ Vg2=800V, ΔVag1=300V, ΔVag1=300V) volts Sensitivity to changing HV at different gaps

Double TGEM1/TGEM2 (new TGEMs) A.Khanzadeev_GSI_April 2010 volts Gas gain X10 3 GG vs. ΔVg1&ΔVg2 (ΔVg1=ΔVg2) (ΔVag=300V, ΔVg1g2=300V, ΔVcg=800V – fixed) He/CF4/iC4H10 (75/23/2) During the test with 55 Fe double TGEM detector showed stable behaviour. Operation of the detector with He based gas mixture allows soft HV regime to get supposed for MUCH electronics value of GG=2∙10 4

Micromegas/GEM Energy resolution fwhm~36% 3.7 mm 2.6 mm 60 mcm Ar/CO2/iC4H10 (90/8/2) GEM – produced by CERN PCB has hidden contact holes GG vs. Vm&ΔVg (Vm=ΔVg) (ΔVmg=100V and 250V, ΔVcg=350V – fixed) Easy to get GG ~4∙10 5 We are taking signals from the mesh A.Khanzadeev_GSI_April 2010

GG vs. ΔVmg (Vm=300V, ΔVg=300V, ΔVcg=350V – fixed) Micromegas/GEM GG vs. ΔVcg (Vm=ΔVg=300V, ΔVmg=250V – fixed) GG vs. Vm (ΔVg=320V, ΔVmg=300V, ΔVcg=400V – fixed) GG vs. ΔVg (Vm=300V, ΔVmg=300V, ΔVcg=400V – fixed) Sensitivity to changing HV at different gaps Ar/CO2/iC4H10 (90/8/2) A.Khanzadeev_GSI_April 2010

He/CF4/iC4H10 (75/23/2) Micromegas/GEM GG vs. Vm (ΔVmg=50V, ΔVg=ΔVcg=0V – fixed) GG vs. ΔVg (Vm=400V, ΔVmg=260V, ΔVcg=400V – fixed) GG vs. Vm&ΔVg (Vm=ΔVg) (ΔVmg=260V, ΔVcg=400V – fixed) During the test with 55 Fe Micromegas/GEM detector showed stable behaviour. Operation of the detector with He based gas mixture allows very soft HV regime to get supposed for MUCH electronics value of GG=2∙10 4. It is enough to keep volts on Gem and volts on Micromegas A.Khanzadeev_GSI_April 2010 Easy to get GG ~4∙10 5

Important remark Technology for production of PCB, hidden contacts to pads from connector side, and production of TGEM are well suited to industrial technology

Plan for 2010 ■ Get NXYTER cards from GSI ■ Adjust GSI cards to prototype connectors ■ Understand how to work with NXYTER ■ Make tests with radioactive sources ■ Deliver prototypes to GSI ■ August/September – beam test in GSI A.Khanzadeev_GSI_April 2010