were also obtained by Manohara and Hanagodimath (2007) for the
case of amino acids.
For the incoherent (Compton) scattering process, the variation
of Zeff with photon energy is shown in Fig. 6. It can be seen that initially
Zeff decreases with increasing energy, minima at 10 keV, and
then it increases with increasing energy up to 400 keV. Finally it remains
constant even with further increase in energy.
For the photoelectric absorption process, the variation of Zeff
with photon energy is shown in Fig. 7. The behavior of Zeff with respect
to energy shows discontinuous jumps in the low energy
range (E < 0.04 MeV) and then it remains constant thereafter. The
energy of these discontinuities corresponds to photoelectric
absorption edges of sodium, aluminum, silicon, calcium and bismuth
as shown in Table 3. These absorption edges are valid immediately
below the absorption edge. In Table 3, the absorption edges
data were shown above 1 keV. From electron configuration, Bi is
heavy element and the valence electron of Bi occupies at n = 6 (P
shell), so K-, L- and M-edges of Bi are shown in the range of energy
as seen in table (above 1 keV). The other elements in glass samples
(Na, Al, Si and Ca) are light elements, so the absorption edge of energy
above 1 keV is shown only K-edge, while L- and M-edges of
their elements are below 1 keV.
The variation of Zeff with photon energy for pair production in
nuclear field is shown in Fig. 8. The values of Zeff decrease rapidly
from 1.25 to 10 MeV and then slightly decrease with further
increasing of photon energy. Fig. 9 shows the variation of Zeff with
photon energy for pair production in electric field. From the figure
it is clear that Zeff is independent of photon energy from 3 to
30 MeV. From 30 MeV to 8 GeV, the value of Zeff decreases with
increasing of photon energy and thereafter it is independent of energy
for bismuth borosilicate glass. These results clearly confirm
the comment made by Hine (1952).
The variation of Ne,eff of bismuth borosilicate glasses with photon
energy for total photon interaction is shown in Fig. 10. The to-