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People Physics Computing Tracker ECAL GCT
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LEAD TUNGSTATE PROPERTIES

Properties of other commonly used Scintillating crystals are also shown
NaI (Tl)
CsI (Tl)
BaF2
BGO
CeF3
PbWO4

Density (g/cm3)

3.67
4.51
4.89
7.13
6.16
8.3
Melting Point (°C)
651
621
1280
1050
1460
1123
Radiation Length (cm)
2.59
1.85
2.06
1.12
1.68
0.89
Molière Radius (cm)
4.8
3.5
3.4
2.3
2.6
2.0
Refractive Index
1.85
1.79
1.50
2.15
1.62
2.2
Peak emission (nm)
410
560
220
480
300
420
Relative Light Yield† (%)
100
45
21
9
6.6
0.3
Decay Time† (ns)
230
1300
630
300
30
36
Temperature coefficient of light yield (%/°C)
~0
0.3
-2
-1.6
0.14
-1.9
†Refers to the slow component of emission (if any).

 

ONE REASON Why cms is compact...

R.Y. Zhu Caltech.

The top photo shows a cube of 1.5X0 of different scintillators and the bottom photo shows three scintillators of different radiation lengths. The CsI sample (used in BaBar) is 16X0 long, the BGO sample (used in L3) is 22X0 and the PbWO4 (CMS) sample is 23X0 long.