R. Pani Department of Experimental Medicine and Pathology University of Rome La Sapienza-Italy. Flat Panel PMT: advances in position sensitive photodetection.

R. Pani

Department of Experimental Medicine and Pathology University of Rome La Sapienza-Italy.

Flat Panel PMT: advances in position sensitive photodetection

8th Topical Seminar on Innovative Particle and Radiation Detectors 21 - 24 October 2002 Siena, Italy

Metal channel dynode PSPMT

Flat Panel H8500 2 inch Final goal

Large FoV PSPMT

Packing density (effective area/outer size) (%)

5 inch 1 inch R7600 2 inch Flat_ panel

57 71 90

10 cm FoV or more

Parameter Flat Panel 1

Flat Panel

23” R2486 5” R3292

R5900 M64

R7600 C8/C12

Window thickness (mm) 2.8 2 3.2 6 1.5 0.8

Dynode structureMetal

channel

Metal

channel

Proximity

mesh

Proximity

mesh

Metal

channel

Metal

channel

Dynode number of stage 12 12 12 12 12 11

Anode structure Multi anode Multi anodeCrossed

wireCrossed

wireMulti

anodeCrossed

wire

Number of anodes 64 (8x8) 64 (8x8) 16+16 28+28 64 (8x8) 4+4/6+6

Pixel size/ pitch (mm) 5.6/6.0 5.6/6.0 3.75 3.75 2/2.25 5/5.5/3.6

Effective area (mm2) 49x49 49x49 50 diam 100 diam 18.1x18.1 22x22

Outer size (mm2) 53x53 52x52 76 diam 132 diam 26x26 26x26

PMT thickness (mm) 15.3 14.7 55 113 20.1 20.1

Intr. charge spread (mm) <1 FWHM ? <1 FWHM ? 7 FWHM 11 FWHM <1 FWHM <1 FWHM

Packing density (effective area/outer size) (%)

85 89 43 57 48 71.6

Cathode luminous sensitivity (A/Lm)

80 50.2 80 80 70 70

Gain 3 10 6 3 10 6 105 105 3 105 7 105

Anode dark current (nA) 96 1.02 20 40 12.8 2

Time response

transit time (ns)6 6 17 ? 5 5

Anode uniformity 1:3 1:2 1:4 1:4 1:5 1:4

Inter-Channel Gain Variation

Flat 1 Flat 2

53 78 80 77 78 91 100 50

48 81 77 72 72 78 88 47

47 94 82 67 62 69 79 43

42 88 81 59 53 59 65 30

45 91 77 60 54 57 65 29

51 90 79 63 58 57 62 32

49 89 72 63 58 60 62 40

30 51 47 41 41 41 44 27

P1-1

P1-8P8-8

P8-1 80 77 69 65 64 63 58 45

89 47 55 62 62 59 58 53

96 79 70 64 59 57 58 54

96 100 81 63 57 64 62 49

92 98 79 61 56 58 63 51

86 89 74 67 63 60 61 55

82 81 72 64 57 56 60 58

73 90 79 71 63 59 63 54

P1-1

P1-8P8-8

P8-1

27 : 100 45 : 100

Flat_panel CsI(Tl) scintillating array

0

100

200

300

400

0 50 100 150 200

Image Pixel

Cou

nts

16x16 array1.4x1.4 mm2 pixel size

15x15 array 3x3 mm2 pixel size

48 mm

57Co flood field irradiation

S.R.= 0,63 mm FWHM

S.R.= 0.72 mm FWHM

26 mm

0

100

200

300

400

500

0 50 100 150 200

Image PixelC

ount

s

24x24 array 1.8x1.8 mm2 pixel size

NaI(Tl) scintillating array

57Co flood field irradiation

Anode disconnected

48 m

m

Flat 1 Flat 2

0

100

200

300

400

0 100 200

Image Pixel

Co

un

ts

020406080

100120140

20 120 220

Image Pixel

Co

un

ts

NaI(Tl) scintillating array 24x24 array 1.8x1.8 mm2 pixel size57Co flood field irradiation

0

50

100

150

200

250

100 200 300 400 500

Image Pixel

Cou

nts

48 m

m

R7600-C12 (1 inch)

0

40

80

120

160

100 200 300 400

Image Pixel

Cou

nts

R3292 (5inch)

0

100

200

300

400

500

600

0 100 200 300

Channel

Cou

nts

0

1000

2000

3000

4000

0 20 40 60 80 100 120 140

Channel

Cou

nts

0

50

100

150

200

250

300

350

0 20 40 60 80

Channel

Cou

nts

NaI scintillating array : Best energy resolution valuesCo57 spot irradiation

Flat Panel 1

11.8 %12,1 %

R3292 (5 inch) R7600-C12 (one inch)

Flat Panel 2

0

50

100

150

200

250

300

0 100 200

Channel

Cou

nts

10,4 %10,4 %

-25

-15

-5

5

15

25

35

0 10 20 30 40 50 60

mm

Dev

iatio

n (C

hann

els)

Flat 1

Flat 2

0

50

100

150

200

250

0 10 20 30 40 50

mm

Cha

nnel

s

0

100

200

300

0 10 20 30 40 50

mm

Cha

nnel

s

Flat 1Flat 2

Position linearity

Flat panel PMT /NaI(Tl) scintillation array

Light spot scanning

ReadoutElectronics Light pulser

Flat panel PMT

Optical Fiber 1mm

4

5

6

7

8

0 5 10 15 20 25 30

Position (mm)

Ano

des

0

1

2

3

4

8

Anode

Cha

rge

(a.u

.)0

1

2

3

4

8

Anode

Cha

rge

(a.u

.)

0

1

2

3

4

8

Anode

Cha

rge

(a.u

.)

6,5mm6mm6mm

Maximum light spread3,5 mm

FWHM1,2mm

Light Spot Scanning

PMT Boundary Response

Anode Crosstalk

- - - - -

- 0,2 1,8 0,2 -

- 1,8 100 2,7 -

- 0,2 2,6 0,3 -

- - - - -

Hamamatsu data Anode 37 Measured value

- - - - -

- <0,1 <0,8 <0,1 -

- <1,4 100 <2,4 -

- <0,1 <1,8 <0,1 -

- - - - -

Anodes1 2 3 4 5S 1

S 2

S 3

S 4

S 5

7 phe

0

1

2

3

0 2 4 6

Position (mm)

Cha

rge

(a

.u.)

2,9

3,4

3,5 4,5 5,5 6,5

Position (mm)

Cha

rge

(a

.u.)

(Max-min)/max = 13%

Spot scanning positions1st metal channel dynode

Intra-Anode Gain Variation

Maximum light spread3,5 mm

FWHM1,2mm

1mm

0

1

2

3

37 45

Anode

Ch

arg

e (a

.u)

0

1

2

3

37 45

Anode

Ch

arg

e (a

.u.)

0

1

2

3

37 45

AnodeC

har

ge

(a.u

)

Anode 45Anode 37

Light spot distribution evaluation

Maximum light spread3,5 mm

FWHM1,2mm

0,5 mm interspace

0

0,25

0,5

1 2 3

Position (mm)

Cha

rge

(a

.u.)

0

1

2

3

4

0 2 4 6Position (mm)

Cha

rge

(a

.u.)

Anode 45

Anode 37

2,5

3

3,5

4

0 1 2 3 4

Position (mm)

Cha

rge

(a

.u)

FWHM = 1,2 mm

Light spot distribution evaluation

Fiber-photocathode distance = 2mm (glass window)

1 mm diameter Fiber

Photoelectrons number = 7

Single Anode Scanning

Total Charge Collected

Missing Charge

N

(DRF) x

zyrxPSFyxdxdyPzrnDRF ,)(),(),(2/122

Position determination by light distribution centroide method

Anger camera principle

DRF = Detector Response Function

P(x,y) = PSPMT gain uniformity response

Spatial resolution = Standard error of the mean value

1 2 3 4 5 6 7 8S 1

S 2

S 3

S 4

S 5

S 6

S 7

S 8

1 2 3 4 5 6 7 8S 1

S 2

S 3

S 4

S 5

S 6

S 7

S 8

1 2 3 4 5 6 7 8S 1

S 2

S 3

S 4

S 5

S 6

S 7

S 8

1 2 3 4 5 6 7 8S 1

S 2

S 3

S 4

S 5

S 6

S 7

S 8

Light Spot Distribution

Anodes

AnodesAnodes

Anodes

FWHM<5 mm

FWHM7 mm

FWHM10 mm

FWHM13 mm

11 phe

0,5

0,8

1,1

1,4

650 750 850 950 1050

High Voltage (V)

Spa

tial R

esol

utio

n (m

m)

11PhePSF 16mm FWHM

Spatial resolution vs high voltage

0

0,2

0,4

0,6

0,8

1

0 5 10 15

mm

Cou

nts

(a.u

.) phe 60

phe 30

phe 7

Light spot irradiation

12345678

S 1

S 2

S 3

S 4

S 5

S 6

S 7

S 8

Light spot FWHM=16 mmPosition distribution

0

10000

20000

0 10 20 30 40 50Channels

Cou

nts

phe7phe 30phe 60

Pulse height distributions

Anodes

S.R. 2 mm S.R. 1,1 mm

Spatial resolution vs energy resolution Light PSF 16mm FWHM

0

0,5

1

1,5

2

2,5

3

0 20 40 60

Energy Resolution (% FWHM)

Spa

tial R

esol

utio

n (m

m)

Phe 60

02468

101214161820

0 0,5 1 1,5 2 2,5

Spatial Resolution (mm)

FW

HM

PS

F (

mm

)

PSF vs Spatial Resolution

11 Phe

FWHM6 mm

0

2000

4000

60 70 80 90 100

Image Pixel

Co

unts

0

2000

4000

60 70 80 90 100

Image Pixel

Co

unts

FWHM7 mm

0

4000

8000

60 70 80 90 100

Image Pixel

Co

unts

FWHM5 mm

0

4000

8000

60 70 80 90 100

Image Pixel

Co

unts

FWHM4 mm

Light Sampling and Position Linearity

2mm step scanning

Anode

6 mm

6 mm6 mm

6 mm