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Plastic scintillators are a solid solution
of luminophors (luminescent additives), in a transparent polymer (polystyrene (PST). Many
characteristics of plastic scintillation materials (light output, transparency to own
emission, decay time, radiation resistance) can be varied by changing their composition.
Polystyrene-based scintillators
Scintillators with a polystyrene matrix are used to detect alfa-, beta, and gamma-
radiation, and fast neutrons. |
Plastic
scintillators are prepared by bulk polymerization in aluminium (size up to 3.5 m) or
glass cast and by pressure molding technique.
By varying the composition, we can produce:
- fast plastic scintillation material: decay time from 0.9 to 0.5 ns, light output
55-50% of anthracene;
- plastic scintillation material having the slow decay component: decay time from 300 to
400 ns, light output 45-40% of anthracene;
- radiation hard plastics (UPS-92RH with dia.16x10 ́́ has 50 % of the initial light
output after irradiation at 18 ̀Rad);
- plastic scintillation material of elevated radiation resistance:
- scintillation polystyrene with the light scattering additive;
- scintillation material for dosimetry;
- scintillation polystyrene containing soluted organic compounds of heavy elements (Pb
-12%, Sn -10%).
|
|
Polystyrene
(PST) |
| Density
[g/cm3] |
1.06 |
| Refractive
index |
1.06 |
| Absorption
coefficient [cm-1] |
0.01-0.003 |
| Softening
temperature [K] |
355-360 |
| Hygroscopic |
no |
| Wavelength
of emission maximum [nm] |
430 |
| Light
output [% of anthracene] |
56 |
| H/C ratio |
1.0 |
| Decay
time [ns] |
2-3 |
|
Selector guide for plastic scintillator.
Scintillator |
Important property |
Application comments |
UPS-89, UPS-923A, UPS-90, UPS-96 |
Very high light output, good transparency, short decay time |
General purpose, particle detection |
UPS-92S |
Slow decay time |
Phoswiches |
UPS-91F |
Ultra fast decay time |
High energy physics, calorimetry |
UPS-92RH |
Radiation hard |
High energy physics, calorimetry |
UPS-96M |
Pressure molding technique, very cheap |
High energy physics, calorimetry |
UPS-976, UPS-971, UPS-972, UPS-973, UPS-974 |
Various wavelengths of maximum emission |
Operation with fiber shifters |
Physical Properties of Plastic Scintillators
Scintillator |
Light output % anthracene |
Wavelength of max. emiss., nm |
Rise time, ns |
Decay time, ns |
Light attenuation length, nm |
Analoges |
UPS-89 |
65 |
418 |
0.9 |
2.4 |
360 |
NE102A |
UPS-923A |
60 |
425 |
0.9 |
3.3 |
400 |
BC400, NE114 |
UPS-90 |
50 |
418 |
1.0 |
3.5 |
400 |
NE110 |
UPS-92S |
44 |
380 |
0.9 |
380-450 |
350 |
BC412, NE115 |
UPS-91F |
39-45 |
390 |
0.7 |
0.6-0.4 |
– |
PilotV, BC422Q |
UPS-92RH |
60 |
425 |
– |
3.5 |
350 |
SCSN81 |
UPS-96M |
55 |
418 |
1.0 |
3.5 |
25 |
none |
UPS-97G |
60 |
425 |
0.9 |
3.3 |
60 |
BC444 |
UPS-971 |
55 |
425 |
0.9 |
|
400 |
none |
UPS-972 |
44 |
435 |
0.9 |
|
400 |
none |
UPS-973 |
45 |
445 |
0.9 |
|
400 |
none |
UPS-974 |
53 |
480 |
0.9 |
|
400 |
none |
|
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