pnpi r&d of the detectors for much e. chernyshova, v.evseev, v. ivanov, a. khanzadeev, b....

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 structure2048 pads with hidden contact holesPad size 1.5x 3 mm2

Working area 102x109 mm2

Gap between pads 0.2 mmPreamp to take signals from mesh or TGEM


TGEM1

TGEM1

Resolution

0

10

20

30

40

50

60

70

80

1040 1060 1080 1100 1120 1140

dVg

fwh

m %

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


TGEM 1

resolution

0

10

20

30

40

50

60

70

80

0 50 100 150 200 250 300 350

Vc

fwh

m %

GG vs. ΔVgc (ΔVg=1.1kV,ΔVag=0.7kV – fixed)

GG vs. ΔVag (ΔVg=1.11kV,

ΔVgc=0.1kV – fixed)


For TGEM1 we can reach Gas Gain up to 12∙103 and energy resolution ~40% without visible problems

Ar/CO2/iC4H10 (90/8/2)

TGEM2

resolution

0

10

20

30

40

50

60

70

80

1290 1300 1310 1320 1330 1340 1350 1360

Vg

fwh

m %

ΔVag=0.6kV,

ΔVgc=0.2kV– fixed


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∙103 and energy resolution fwhm~40% without visible problems

Ar/CO2/iC4H10 (90/8/2)

TGEM2

Double TGEM1/TGEM2

resolution

0

10

20

30

40

50

60

70

80

0 100 200 300 400 500

Vggfw

hm

%

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∙103 and energy resolution ~35% without visible problems

1.0 mm

0.5 mm


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)

800 850 900 950 1000 850 900 950 1000

GG vs. Δ Vg2 (ΔVg1=750V, ΔVg1g2=450V, ΔVag1=450V, ΔVgc=50V

During the test with 55Fe 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∙104


Drawback – to have good collection of primary electrons (shape and resolution of the 55Fe 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.


Double TGEM1/TGEM2 (new TGEMs)

Ar/CO2/iC4H10 (90/8/2)

GG vs. ΔVg1&ΔVg2 (ΔVg1=ΔVg2) (ΔVag=300V, ΔVg1g2=300V, ΔVcg=800V)

GG

x10

3

TGEM1, TGEM2 are identical:

thickness – 0.53 mm

step between holes – 1 mm

hole diam.– 0.6 mm

rim diam.- 0.74 mm

volts

Res

olu

tio

n, %

ΔVg, volts


For new double TGEM1/TGEM2 we can reach Gas Gain up to 30∙103 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)


2

3

4

5

6

7

8

9

200 250 300 350 400 450

0

2

4

6

8

10

100 150 200 250 300 350 400 450


Gas gainX103

volts

Gas gainX103

Gas gainX103

2

3

4

5

6

7

8

200 300 400 500 600 700 800 900volts

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



volts

Gas

gai

n X

103

GG vs. ΔVg1&ΔVg2 (ΔVg1=ΔVg2) (ΔVag=300V, ΔVg1g2=300V, ΔVcg=800V – fixed)

He/CF4/iC4H10 (75/23/2)

During the test with 55Fe 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∙104

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∙105

We are taking signals from the mesh


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)


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 55Fe 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∙104. It is enough to keep 320-330 volts on Gem and 320-330 volts on Micromegas


Easy to get GG ~4∙105

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


pnpi r&d of the detectors for much e. chernyshova, v.evseev, v. ivanov, a. khanzadeev, b....

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