Half Value Layers (in cm)
for Gamma and X-Ray Radiations
at Varying Energies for Various Materials

ENERGY
MeV
LEAD
(Density=
11.35g/cm^3)
IRON
(Density=
7.86g/cm^3)
ALUMINUM
(Density=
2.82g/cm^3)
WATER
(Density=
1g/cm^3)
AIR
(Density=
.0013g/cm^3)
STONE
CONCRETE
(Density=
2.35g/cm^3)
  HVL HVL HVL HVL HVL HVL
0.3 0.160 0.845 2.457 5.823 5.133x10^3 2.76
0.5 0.396 1.062 2.936 7.532 6.243x10^3 3.39
1.0 0.816 1.471 4.225 9.760 8.451x10^3 4.65
1.5 1.174 1.833 5.058 12.157 10.343x10^3 5.72
2.0 1.358 2.074 6.187 13.860 12.375x10^3 6.66
2.5 1.443 2.294 6.794 15.750 13.860x10^3
3.0 1.474 2.483 7.372 17.769 15.065x10^3 8.15
3.5 * 1.506 2.585 7.965 19.250 16.500x10^3
4.0   2.760 8.349 20.382 17.769x10^3 9.36
5.0   2.851 9.625 23.100 20.382x10^3 10.34
10.0   * 2.948 11.745 30.130 24.750x10^3 13.86
20.0     * 12.157 38.500 33.000x10^3 * 14.14
30.0       40.764 33.640x10^3  
40.0       * 43.312 * 34.650x10^3  
* Value beyond which the Half Value Layer (HVL)
will not increase regardless of increase in energy