# Method of Calculating Percentage Depth Dose for Diagnostic Xâ€‘rays by iaj67571

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```									Received Jan. 6, 2004;    Revision accepted May 26, 2004;       Code No. 873

Summary

Key words: Diagnostic X-ray, Percentage depth dose, Monte Carlo simulation
f                                                R
d
D d R

D( d , R) = Dp ( d ) + Ds ( d , R)

Dp d                                             Ds d R

Dp ( d ) = ∫0 max ∆Dp ( E, d ) ⋅ ω ( E ) ⋅ dE
E

∆Dp E d                               d                          E

2
 f 
∆Dp ( E, d ) = ∆Dp ( E, 0) ⋅ exp{− µ ( E ) ⋅ d} ⋅       
 f + d

E                                E

E

Φ( E )
ω ( E) =                                                                                                          f    f +d
Φ( E ) ⋅ dE
Emax
∫
0

Φ E                                  E
E max                                                                                                                                          R

2
Ds ( d , R) = ∫0 max ∆Ds ( E, d , R) ⋅ ω ( E ) ⋅ dE
E
 f  R⋅ f + d
∆Ds ( E, d , R) =        ⋅ ∫ f 2πr ⋅ F(r ) ⋅ δ ( E, d , r ) ⋅ dr
 f + d 0
∆Ds E d R                                    E                                R
d                                     F r               r

2
 f  R⋅ f + d
∆Ds ( E, d , R) =        ⋅ ∫ f 2πr ⋅ δ ( E, d , r ) ⋅ dr
 f + d 0

E
E d r                                                                  E                 ∆D p E
E
d                                                 r                                                             d                                            r
E d r                                                                                         E d r
∆Dp E              E d r
Dp d                             Ds d R
Dp d
∆Ds E d R                                        E d r                 ∆Dp E
Ds d R

f       f+d                                     E               ∆Dp E
F r

E d r

∆

∆Dp E
E d r

− =               −
=

E
E

∆Dp E
E d r

E       ∆D p            ×
E
=   =   ×

×   ×

×        ×

×                                     ×

×

E
∆Dp E                           ∆Ds E d R
∆Dp
E           ∆Ds E d R

×                         =
=
=                           =       =       ×

’   =               ’       =
=       ×                   =

×
’           =       =   =
=   ×

=
×       ×           ×

=
=   ×

×

×       ×           ×
’   =       ’   =
=               =

=       =
×
E d r
F r

=                     =   ×

=           =

=                     =   ×

=                     =   ×

=       =

=                     =   ×

=               =

=                                 =   ×

=

=

```
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