Systematic Study of Strip/Block Scintillators: Progress Report

E.P. Jacosalem, S. Iba, N. Nakajima, H. Ono, A.L. Sanchez, A.M. Bacala & 　 H. Miyata

ILCCAL TV MeetingJune 13, 2005

Outline:

Background of the study Research Design and Methodology Scintillator’s surface covering and

length variation WLS fiber’s length variation Results Summary Future plans

R&D for new calorimeters to achieve accurate measurements of the SM

Accurate & precise measurements require fine segmentation

Fine segmentation can be acquired from small scintillators

Motivated to come up with new calorimeter design

Background of the study

Trigger : Scintillator (about 1cmx8cmx5mm ) directly connected to PMT

Source : 90Sr (beta-ray) PMT (sensor) : 16 Ch MAPMT H6568-10, HV : -950V PMT (trigger) : H3164, HV : -900V Sensor : Strip type scintillator ( length: 4,8,12, 16cm) Block type scintillator (thickness: 2, 4, 5, 6 and 8mm) WLS fiber diameter: 1.0mm ; 1.6mm (length: 20, 40, 60, 80, 100,

120, 180, 300 cm)

Setup

Research Design & Methodology

3M　Reflective　Mirror

Teflon

Black　Sheet

White　Paint　with　Teflon

Gold　Coat

White　Paint

Aluminum　Evaporation

White　Paint　Surface　Covering　(1.7mm　groove　for　1.6mm　WLS　fiber)

10x60x2mm　

Scintillator’s surface covering and length variation

10x40x2mm　scintillator　(1.1mm　groove)

Compare each type using ADC system Use WLS fiber with diameter of 1.0mm and 1.6mmDetermine the systematic error

10x160x2mm　

10x80x2mm　

10x40x2mm　

10x120x2mm

Research　Design　&　Methodology　cont..

Results

　3M　reflective　mirror　has　the　greatest　light　yield

PH　increasing　with　scintillator　length　on　3M　reflective　mirror,　teflon,　white　paint　with　teflon　and　aluminum　evaporation.　

PH　is　almost　constant　with　scint　length　on　white　paint　and　black　sheet　surface　coverings.

　No　comparison　for　gold　coat　since　cannot　do　gold　coating　for　strips　longer　than　40mm.

20 mm 40 mm 80 mm 120 mm 160 mm

0

10

20

30

40

50

60

70

80

90

100

110

120

130

Sensor's Length and Surface Covering DependenceWLS fiber dia: 1.0mm

3M Reflective mirror

White Paint with teflon

Aluminum Evaporation

Teflon

White Paint

Black Sheet

Gold

Sensor's Length

Pul

se H

eigh

t (A

DC

Cou

nts)

20 mm 40 mm 80 mm 120 mm 160 mm 180 mm

0

25

50

75

100

125

150

175

200

225

Sensor's Length and Surface Covering DependenceWLS fiber dia: 1.6mm

3M Reflective mirror

White Paint with teflon

Aluminum Evaporation

Teflon

White Paint

Black Sheet

Sensor's Length

PUlse

Heig

ht (A

DC C

ount

s)

Results cont..

3M reflective mirror has the highest pulse height

PH slightly increases with sensor’s length on 3M reflective mirror, teflon, and white paint with teflon

PH on white paint, aluminum evaporation and black tape are almost constant.

0 20 cm 40 cm 60 cm 80 cm 100 cm 120 cm 180 cm 240 cm 300 cm 320 cm-1.4-1.3-1.2

-1.1-1

-0.9

-0.8-0.7-0.6

-0.5-0.4-0.3

-0.2-0.1

0

WLS fiber Length Dependence(3M reflective mirror)

1.00mm dia

1.6mm dia

WLS fiber length

Ln o

f AD

C C

ount

s

Results cont…

Sensor’s　type:

　3M　　　reflective　　mirror　covered　10x40x2mm　scint.

　varying　WLS　fiber　length

　plotted　the　ln　of　ADC　count　to　achieve　the　attenuation　length

Attenuation　Length　1.6mm　dia　　　=　2.01m1.0mm　dia　　　=　1.19m

Summary

3M reflective mirror covered scintillator found to have the greatest pulse height.

Scintillators using 1.6mm WLS fiber had greater PH compared to scintillators with 1.0mm fiber

PH increasing with scintillator length on 3M reflective mirror, teflon, white paint with teflon and aluminum evaporation.

PH is almost constant with sensor’s length on white paint and black sheet surface coverings.

Attenuation　Length　: 1.6mm　dia　　　=　2.01m 1.0mm　dia　　　=　1.19m

Future plans:

Do ADC measurements for block-type scintillators (thickness varied).

Do ADC measurement for position dependence for strip type scintillator.

Do simulation for light transmission for strip type.