Final Report - Strategic Environmental Research and Development ...

S-Parameter
S-Parameter
Penetration Depth (m)
The presence of a peak in S parameter depth profile is an indication of a multilayer structure in
the film from annihilation characteristic difference between those layers. From the variation of S
parameter depth profile in Figure 5.33b, it suggests that there exists approximately 100 nm of
polymer skin from the surface of the aged Deft-084 primer film. Inside the polymer skin there
exists an intermediate transition layer (about 0.1-2.5 mm thickness) where pigments start to
disperse with the polymer and other additives. Beyond the transition layer it is the bulk layer of
the primer film where the S-parameter remains close to a constant with the depth.
0.49
0.485
0.48
Deft-098(21-day)
Deft-098(24-day), back side
Mean depth
5.0
4.5
4.0
3.5
0.475
0.47
3.0
2.5
2.0
0.465
0.46
1.5
1.0
0.5
0.455
0.0
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Energy (keV)
(a)
0.49
0.485
Deft-098(21-day)
Deft-098(24-day), back side
0.48
0.475
0.47
0.465
0.46
0.455
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
Mean depth (m)
Figure 5.33. S parameter for aged Deft-084 film (a) as a function of positron incident energy (b)
as a function of mean depth.
(b)
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