Electroluminescence yields in MicroMegas , THGEM and GEM

7th RD51 Collaboration Meeting13-15 April, 2011, CERN


H. Natal da Luz1, C.M.B. Monteiro1, J.M.F. dos Santos1, C. Balan1, E.D.C. Freitas1, J.F.C.A. Veloso2, A. Breskin3,

T. Papaevangelou4, I. Giomataris4

1University of Coimbra, Portugal2University of Aveiro, Portugal

3Weizmann Institute of Sciences, Israel4Centre d’Études Nucléaires de Saclay, France

Electroluminescence yields in MicroMegas, THGEM and GEM

7th RD51 Collaboration Meeting13-15 April, 2011, CERN 2

Outline

Motivation; Experimental setups with different

MPGDs and UV sensitive LAAPDs; Methods for determination of Electro-

luminescence yields; Results; Conclusions.


Motivation

Rare event experiments (eg.: dark matter search, neutrinoless double beta decay) can take advantages of reading charge and scintillation light produced by MPGDs;

Decoupling of electronic noise; Usually much better SNR.



Gap: 50 mmHole diameter: 25 mm

Thickness: 0.4 mmHole diameter: 0.4 mmRim: 0.1 mm

MicroMegasTHGEM/GEM

MPGD scintillation vs. charge readout


Charge (a) and scintillation (b) pulse-height distributions in MM

LAAPD gain ~ 30

0 100 200 300 400 500 600 7000

500

1000

0

500

0

500

0 100 200 300 400 500 600 700b)

Channel Number

2 bar

Co

un

ts

6 bar

10bar

0 100 200 300 400 500 600 7000

500

10000

500

0

500

10000 100 200 300 400 500 600 700

a)

Channel Number

2 bar

Co

un

ts

6 bar

10bar


MM EL Yield

0 100 200 300 400 500 600 7000

500

1000

0

500

0

500

0 100 200 300 400 500 600 700b)

Channel Number

2 bar

Cou

nts 6 bar

10bar

0 100 200 300 400 500 600 7000

500

10000

500

0

500

10000 100 200 300 400 500 600 700

a)

Channel Number

2 bar

Cou

nts 6 bar

10bar

1 2

xE

x

ScUVeff w

ENY

QE

N

A

AN XRe

X

ScUV

,

3, 101.6

eV 62.3

eV 22100XReN

------------------------

APD

toteUV G

GQEN 1

,

ScUVeff NY

2


MM charge gain in Xe


Maximum charge gain Vs pressure (Xe)

0 1 2 3 4 5 6 7 8 9 10 11100

101

102

103

104

0 1 2 3 4 5 6 7 8 9 10 11

100

101

102

103

104

Max

imu

m G

ain

Pressure (bar)

MM-charge MM-scint S-THGEM S-GEM 3-GEM MHSP


MM Charge gain fluctuations (Xe)

300 400 500 600 700 800 9000,10

0,15

0,20

0,25

0,30

0,35

0,40

0,45

0,50

0,55

0,60

300 400 500 600 700 800 900

0,10

0,15

0,20

0,25

0,30

0,35

0,40

0,45

0,50

0,55

0,60

a)

1 bar 2 bar 3 bar 4 bar 5 bar 6 bar 7 bar 8 bar 9 bar 10 bar

En

erg

y R

es

olu

tio

n (

Ch

arg

e)

VMM

(V)

22 keV X-rays


MM gain in scintillation-readout (Gtot = primary charge/charge out from LAAPD)

LAAPD gain ~ 30

300 400 500 600 700 800 900102

103

300 400 500 600 700 800 900

102

103

b)

1 bar 2 bar 3 bar 4 bar 5 bar 6 bar 7 bar 8 bar 9 bar 10 bar

Ga

in -

sc

inti

lla

tio

n c

ha

nn

el

VMM(V)


Charge-to-scintillation gain ratio

300 400 500 600 700 800 900 1000

0,1

1300 400 500 600 700 800 900 1000

0,1

1

1 bar 2 bar 3 bar 4 bar 5 bar 6 bar 7 bar 8 bar 9 bar 10 barG

ain

Ra

tio

(C

ha

rge

/Sc

inti

lla

tio

n)

VMM(V)

Lower E/p favours excitations


Absolute EL Yield “out” of MM (Xe)

300 400 500 600 700 800 900 1000

102

103

300 400 500 600 700 800 900 1000

102

103

10 bar9 bar

8 bar7 bar

6 bar

5 bar

4 bar

3 bar2 bar

1 bar

Yef

f (

ph

oto

ns

/ p

rim

ary

e- )

VMM

(V)

• Double mesh, uniform field scintillation gap yields

466 photons/e-/cm @ 4.1 kV/cm/bar


THGEM Gains in Xe

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

1.E+06

1.E+07

0 500 1000 1500 2000 2500 3000

Ab

so

lute

Ga

in

DVTHGEM (V)

1.0 bar

1.5 bar2.0 bar

2.5 bar

1.0 bar

2.0 bar 3.0 bar

APD gain ~150


THGEM EL yield in Xe

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

0 500 1000 1500 2000 2500 3000

Ele

ctr

olu

min

es

ce

nc

e y

ield

(P

h /

pri

ma

ry e

- )

D VTHGEM (V)

1.0 bar

1.5 bar2.0 bar

2.5 bar


Statistical fluctuations in THGEM

0

5

10

15

20

25

30

35

40

0 500 1000 1500 2000 2500

En

erg

y R

es

olu

tio

n (

%)

DVTHGEM (V)

2.0 bar

2.5 bar

1.5 bar1.0 bar


GEM gain in Xe

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

100 200 300 400 500 600 700

Ga

in

DVGEM (V)

1.0 bar1.5 bar

2.1 bar2.5 bar

1.0 bar1.5 bar

2.1 bar

2.5 bar


GEM EL yield (Xe)

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

100 200 300 400 500 600 700

Ele

ctr

olu

min

es

ce

nc

e y

ield

(P

h /

pri

ma

ry e

- )

DVGEM (V)

1.0 bar1.5 bar

2.1 bar2.5 bar


GEM statistical fluctuations

0

10

20

30

40

50

60

100 200 300 400 500 600 700 800 900

En

erg

y R

es

olu

tio

n (

%)

DVGEM(V)

1.0 bar charge

1.5 bar charge

2.0 bar charge

2.5 bar charge

1.0 bar scint

1.5 bar scint

2.1 bar scint

2.5 bar scint


THGEM in Ar

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

0 500 1000 1500 2000 2500

Abs

olut

e G

ain

D VTHGEM (V)

1.1 bar1.5 bar

2.1 bar2.5 bar

1.0 bar

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

0 500 1000 1500 2000 2500

Elec

trolu

min

esce

nce

yie

ld

(Ph

/ prim

ary

e- )

D VTHGEM (V)

1.1 bar1.5 bar

2.1 bar 2.5 bar


GEM in Ar

1.0E+01

1.0E+02

1.0E+03

1.0E+04

100 200 300 400 500 600 700

Gai

n

DVGEM (V)

1.0 bar2.0 bar

1.0 bar 2.0 bar

1.5 bar

2.5 bar

3.0 bar

1.0E+00

1.0E+01

1.0E+02

1.0E+03

200 250 300 350 400 450 500 550

Elec

trol

umin

esce

nce

yie

ld

(Ph

/ pri

mar

y e

- )

DVGEM (V)

1.0 bar2.0 bar

2.5 bar

1.5 bar


Conclusions

Table I – Maximum gain and scintillation yield for GEMs and THGEMs

operating in argon and xenon at 1 bar and 2.5 bar.

Xenon Argon

1 bar 2.5 bar 1 bar 2.5 bar

GEM Gain 1.5 × 105 4 × 104 5 × 103 5 × 103

Yield 6 × 103 1.5 × 103 3 × 102 3 × 102

THGEM Gain 1.2 × 106 4 × 104 1.2 × 105 3 × 104

Yield 7 × 104 2 × 103 1.5 × 104 4 × 103

• Double mesh, uniform field scintillation gap yields

466 photons/e-/cm @ 4.1 kV/cm/bar


Documents

Electroluminescence yields in MicroMegas , THGEM and GEM