Definition material at MCNP(4c) code

[ali khotbesara]

Homework Statement

gamma beam (γ) consequent of co 60 [this source have two beam; 1.1732mev(99.88%) & 1.3325mev(0.12%)] radiation behind the concrete block [ 300×300×20 cm] (thickness is 20 cm).
analysis and plot Gamma-Ray Attenuation at 5 cm layers (4 layer) and plot spectrum of exited photons.

Homework Equations

(between source and target is void)

The Attempt at a Solution

this program is a part of solution that i write it:

1 1 -2.4 -1 2 -3 4 -5 6
2 0 #1

1 pz 300
2 pz 0
3 py 20
4 py 0
5 px 300
6 px 0

imp:p 1 0
mode p
sdef par=2 erg=d1 pos=150 0.001 150
si1 l 1.1732e-6 1.3325e-6
sp1 0.9988 0.0012
m1 $ ( how Defined this material for concrete block !? )
f1:p 1
tmesh
rmesh1:p popul
cora1 0 150
corb1 0 3i 20
corc1 0 150
endmd
nps 1000

 

[ali khotbesara]

hi, pleas guide me and say my mistakes.
Regards.