Environmental Engineering Reference
In-Depth Information
MTF
y = a exp(-bx) + c exp(-dx)
Inverse Fourier Transform
y = 2ab/(4π
2
x
2
+b
2
) + 2cd/(4π
2
x
2
+ d
2
)
LSF
Inverse Abel Transform
f(r
2
) = ab/[4π
2
{r
2
+ {b/2π)
2
}
3
/
2
] + cd/[4π
2
{r
2
+(c/2π)
2
}
3
/
2
]
PSF
FIGURE 6.4
Transition.for.point.spread.function.
TABLE 6.2
FWHM.List.by.PSFs
Energy
(kVp)
Thickness
(µm;mg/cm
2
)
FWHM
(µm)
(a)Gd
2
O
2
S:Tb
. 25
. 26
. 27
48;.35
46;.34
46;.34
82;.60
21.41
47.93
40.60
91.01
. 28
. 30
. 90
40;.29
44;.32
68;.50
68;.50
37.56
20.65
37.46
38.28
109;.80
51.75
(b)CsI:Tl
. 20
a
. 35
a
. 50
a
. 30
150;.68
150;.68
150;.68
150;.68
23.09
25.99
23.85
29.73
200
147;.47
. 299;.135
29.63
34.98
a.
20,.35,.50.are.keV.units.
The.isotropic.case.is.as.follows:
(
)
=
.
E
θ φ
,
E sin
⋅
θ
.
(6.2)
I
so
1
where.θ.and.φ
are.the.meridian.and.azimuthal.angles.of.the.photons.
Search WWH ::
Custom Search