Barium
fluoride or BaF2 crystal is of high transmission and good
scintillation. As a scintillation crystal, it has two components with
different decay times. Its remarkable characteristic is that it is the
fast one in the known scintillation crystals, and that its fast/slow
component ratio changes little with temperature. So BaF2
crystal is applied widely to the field concerned to the study of positron
annihilation, such as materials science, particle physics and nuclear
medicine.
New Rise
Optics can supply BaF2 crystals up to 50�50�350mm3
(cuboids) or φ140�150mm (cylinder).
Scintillation
Properties
|
|
Space
group
|
Fm3m
|
Cleavage
|
(111)
|
Density
(g.cm-3)
|
4.89
|
Melting
point (�C)
|
1280
|
Hardness
(Mho)
|
3
|
Hygroscopic
|
No
|
Radiation
length (cm)
|
2.06
|
Peak
emission (nm)
|
310(slow),220(fast)
|
Decay
constant (ns)
|
620(slow),0.6(fast)
|
Refractive
index at peak emission
|
1.51(slow),1.49(fast)
|
Afterglow
(after 3ms) (%)
|
0.005
|
Light
output relative to Nal(Tl) (%)
|
20%(slow),4%(fast)
|
|
|