Thebackground of CALIFA CsI(Tl) elements

for detailed description of CALIFA elements, see CWG video report Feb 26,2008 by V. Avdeichikov

Crystals produced by Amcrys Ltd., Khar’kov (Ukraine)

CALIFA - 90º elements

10x30x130x15x42 mm**3

Forward Cap elements??

20x20x210x26x26 mm**3

Calorimeters for HEP. Amcrys Ltd production

MeV100@%8.2E

MeV400@%9.1E

CsI(Tl)

BELLE (KEK) barrel 4640 pcs. 22.52 tonsendcap 1506 pcs. 7.87 tons

BaBar (SLAC) barrel 1643 pcs. 6.281tonsendcap 216 pcs. 0.78 tons

device crystal modules103

depthX0

photosensor BT

where beam energy

GeV

Belle CsI(Tl) 8.8 16 Si PD 1 KEK 8+3.5

BaBar CsI(Tl) 6.8 16 Si PD 1 SLAC 9+3.1

M.Moszynski CsI(Tl)/0.8 cm**3

Our data

CsI(Tl)/APD (10x10), Energy resolution for rays. Batch of 8 CsI.

( <M>=50, ALICE Preamp., shaping time = 2 s)

12 CsI(Tl) Khar’kov samples

<M>=100

V.Avdeichikov, NUSTAR meeting GSI Jan-08

C sI (T l )/A P D (10x10)< M > = 50

0. 569

0. 660 1. 063 M eV

1. 33

2. 50

C ol lected L ight, channels

C sI (T l )

A P D

Ene

rgy

Res

olut

ion,

%

l = 130 mm10x3

0 15x4

2

10x1

0

1

2

3

4

5

6

7

89

10

600 800 1000 2000 3000 5000

CsI(Tl)/APD in

CALIFA-4 samples

1. Whole CsI(Tl) volume is irradiated. LO non-uniformity for tested crystals have been modified to 0.15 – 0.28%

2. Original LO inside one batch energy resolution 10% - 15%

3. 44-51% of Light is collected by the lightguide

4. We are close to the limit in R%

(Solid lines is driven to guide an eye)

(Shaping time – 2 s)

sL ight O utput, channels

T _ protons = 180. 0 M eV

K har ' kovSt. G obain

P ulser , = 4. 3 channels

Energy Resolu

tion, %

0

0. 2

0. 4

0. 6

0. 8

1

0 500 1000 1500 2000 2500 3000 3500 4000

Protons

Gammas

K har ' kov

St. G obain

L ight O utput, channels

Ene

rgy

Res

olut

ion,

% T _ proton = 180 M eV

0

0. 2

0. 4

0. 6

0. 8

1

0 500 1000 1500 2000 2500 3000 3500 4000

0.4%

0.6%

CWG meeting April 08

C sI (T l )/A P D (10x10)< M > = 50

0. 569

0. 660 1. 063 M eV

1. 33

2. 50

C ol lected L ight, channels

C sI (T l )

A P D

Ene

rgy

Res

olut

ion,

%

l = 130 mm10x3

0 15x4

2

10x1

0

1

2

3

4

5

6

7

89

10

600 800 1000 2000 3000 5000

Extra long, 210 mm, CsI(Tl) crystals

20x20x210x26x26 mm**3

Option forForward Cap?? for the EXL setup??

20x20

26x26

10x10

L=210 mm, V=110 cm^3

Some preliminary test results…..

Collected Light, channels

Ener

gy R

esol

utio

n, %

CsI(Tl)/APD(10x10)

<M> = 50

0.5690.660

1.063 MeV

1.33

2.50

APD

CsI(Tl)

l = 210 mm20x2

0 26x 2

6 10x 1

0

1

2

3

4

5

6

7

89

10

600 8001000 2000 300040005000

C sI (T l )/A P D (10x10)< M > = 50

0. 569

0. 660 1. 063 M eV

1. 33

2. 50

C ol lected L ight, channels

C sI (T l )

A P D

Ene

rgy

Res

olut

ion,

%

l = 130 mm10x3

0 15x4

2

10x1

0

1

2

3

4

5

6

7

89

10

600 800 1000 2000 3000 5000

Energy resolution of 130 mm CsI(Tl)/APD elements for -rays. 12 elements measured

LO uniformity = (0.30 – 0.70)%

Energy resolution of 210 mm CsI(Tl)/APD elements for -rays. 3 elements measured.

LO uniformity = (0.5-1.0)%

C hannels

Shielded by A l , 1mm , box

Shielded by P b, 40mm, boxN (> 50 keV ) = 65 1/ sec

N (> 50 keV ) = 170 1/ sec

C sI (T l ) element, 55 cm3

(1. 461 M eV - K 40)

1

10

10 2

10 3

0 500 1000 1500 2000 2500 3000 3500 4000

C hannels

C sI (T l ) element, 55 cm3

C sI (T l )/A P D

C sI (T l )/ P M T

50 keV

N (> 50 keV ) = 170 1/ sec

P ulser , 8. 7 keV - F W H M

x2

1

10

10 2

10 3

0 200 400 600 800 1000

background counting rate for CALIFA-5 element with E> 50 keV

Noise tail??

Al, 1 mm

Pb, 40 mm

Threshold will depend on light collection. For Califa CsI/APD(10x10) the Light Collection is around 44-51%. Spectroscopic threshold, in average, 25 keV(see next slide)

For Califa CsI/PMT element threshold, in average, 10 keV

Natural -background for 6000 Califa elements equal to 1.0*10^6 events/sec ( > 50 keV). What is the trigger structure??

Spectroscopic threshold – 25 keV

Noise – 8.7 keV (FWHM) for 44-51% of Light Collection. 10x30x130x15x42 mm**3 CsI(Tl)

Noise – 4.3 keV (FWHM) - Moszynski., NIMA 485(2002)504 in case of 100% of Light Collection. 0.8x10x10 mm**2 CsI(Tl) .Threshold –10 keV

C hannels

X - l ine, 59. 5 keV

B ackround for 2 hour s

T hreshold25 keV

C al i fa-5 C sI (T l )

0

2

4

6

8

10

12

20 40 60 80 100 120 140 160 180 200

10-1

1

10

10 2

10 3

20 40 60 80 100 120 140 160 180 200

Califa-5 element. Spectrum of Am241 X-line ( 59.5 keV). Spectroscopic threshold around 25 keV

-background, accumulated during 2 hours, low-energy part, 170 1/sec

A threshold of 100 keV a large reduction of background

Other points to be raised for discussion (LU, 16 April 2008)

-The possible use of PD+PA(ALICE/PHOS)

- The optional choice of 210 cm CsI(Tl) for forward cap

-The in-beam tests at TLS and TDU

- The DEMONSTRATOR(s) and their interface to Si tracker, FEE and DAQ

CWG, 16 April 08, LU