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In order to compute the intensity of optical light for an on-axis source,
the Airy function for each mirror was computed at two wavelengths: 450
nm and 850 nm, corresponding to the peak transmission wavelengths of the
optical blocking filters. The reflectivity in the optical band at these
grazing angles of incidence is very high, 
99%,
based on the optical constants found by Weaver (1977). The contributions
to the Airy function from each mirror annulus were added incoherently,
as no effort was made during fabrication to align the mirrors to the accuracy
necessary to maintain coherence. An example of the results of the calculation
for the two wavelengths is shown in Figures C.1,
C.2,
and C.3. The fraction of the
encircled energy for the pixel at the on-axis point was taken to be 0.03
and 0.06 at 850 nm and 450 nm respectively. In the integration over the
bandpass carried out to compute the optical fraction transmitted, OF (see
Equation 5.18), the encircled energy was
computed at a number of wavelengths and interpolated linearly with wavelength.
The encircled energy is included in the term Atel(
).
Figure C.1 shows the point spread
function of the telescope computed at 450 nm. The small `dips' are interference
effects. This curve was multiplied by 
,
where 
is the off-axis angle
variable of integration and integrated to a specific off-axis angle to
produce the results shown in Figure C.2.
The same procedure was used to produce the results at 850 nm, shown in
Figure C.3.
Figure C.1: The point spread function
of the AXAF mirrors at 450 nm as a function of off-axis angle in arc seconds.
Figure C.2: The encircled
energy as a function of off-axis angle for the AXAF mirrors at 450 nm.
Figure C.3: The encircled
energy as a function of off-axis angle for the AXAF mirrors at 850 nm.
