Orsay - December 2007IPNO-RDD-Jean Peyré 1

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Work at IPN Orsay

R&D on Calorimeters

Jean PeyréDec 2007

Orsay - December 2007IPNO-RDD-Jean Peyré 2

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1: R&D Status at IPNO

Prototypes for Calorimeter

Dual Square PMTs (1 per 2 crystals) received from

Photonis (3 PMT 9 stages)

CsI(Tl) Crystals received from Scionnix

Orsay - December 2007IPNO-RDD-Jean Peyré 3

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r1: Xtals received from

Scionnix

Frustum Crystals #2 have been send back to Scionnix for non conformity

Reference Crystals #1 are kept for Xtalk tests

Crystal #1

Crystal #2

Orsay - December 2007IPNO-RDD-Jean Peyré 4

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r1: Xtals ordered from other

manufacturers

New crystals ordered :- Amcrys (Russia) and SICCAS (China)

Standard crystal 110mm long and lengthened crystal 140mm long to be able to protect PMT against Magnetic field with metal

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1: PMT’s

3 PMT’s-1 with window thickness 3mm-1 with window thickness 2mm-1 with window thickness 3mm + saw line

3mm

2mm 3mm+saw line

saw line

Orsay - December 2007IPNO-RDD-Jean Peyré 6

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r1: PMT’s- measure of

Crosstalk

We want to measure the Crosstalk between the two channels of the PMT when placing a crystal in front of one of the two channels.

Case AS1a=G1*NbPhé1a

S2a=G2*NbPhé2a

Case BS1b=G1*NbPhé1b

S2b=G2*NbPhé2b

Cross-Talk CH1->CH2NbPhé2a/NbPhé1a=S2a/S1a*G1/G2

CH1

CH2

CH1

CH2

Cross-Talk CH2->CH1NbPhé1b/NbPhé2b=S1b/S2b*G2/G1

NbPhé= Number of Photoélectrons created on each part of the photocathode & collected by first dynode

G= global Gain for each Channel(PMT+ChargePream+Shaper)

S= signal for each channel CH

Orsay - December 2007IPNO-RDD-Jean Peyré 7

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r1: PMT’s- measure of

Crosstalk

Cross-Talk = (S1b/S2b*S2a/S1a)1/2

Cross-Talk CH2->CH1 Cross-Talk CH1->CH2Are supposed equal(estimation of ±12% variation between both)

Window 3mm Window 2mm Window 3mm+saw line

Xtalk1 8.88% 7.95% 5.83%

Xtalk2 3.69%

Xtalk1= standard CrosstalkXtalk2= standard Crosstalk measured with a black foil

inserted in the saw line

The standard production of PMT will certainly provide a quite constant crosstalk between channels: easy to correct

Orsay - December 2007IPNO-RDD-Jean Peyré 8

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r2: Study of thin envelops for

LaBr3 Xtals with Saint-Gobain

LaBr3 with Standard package(thickness 2mm)

LaBr3 with Aluminium+Carbon package(thickness < 0,3 mm)

R% FWHM @662keV =2.9%

R% FWHM @662keV =3.3%

17x17x6mm

diam25x25mm

Orsay - December 2007IPNO-RDD-Jean Peyré 9

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3: Magnetic field R3B

Magnetic field along Zm axis of Magnet

600 Gauss

(0,0,0) m

Zm

Xm

Beam axis14°

Target

1450mm

R3B Calorimeter

2.2T Magnet

Ym

Zc Yc

Xc

(0,0,0) m

Zm

Ym

Beam axis

2.2T Magnet

Xm

ZC

YC

XC

R3B Calorimeter

Discussion with J.E. Ducret from CEA Saclay on September 24th, 2007

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3: Magnetic field R3B

(0,0,0) m

Zm

Xm

Beam axis14°

Target

1450mm

R3B Calorimeter

2.2T Magnet

Ym

Zc Yc

Xc

Iron wall 2m*2m*10cm

News from J.E. Ducret December 2007: simulation of an iron cylinder around the calorimeter with a clearance of 10 cm around the barrel. iron wall seems not so easy to implement between calorimeter and magnet.

New meeting with J.E. Ducret on October 31th 2007People from Saclay are going to simulate the addition of a 2m*2m*10cm iron wall to protect the calorimeter from magnetic field

Iron cylinder