Half-Value and Tenth-Value Layers for X-ray and Gamma ray Radiation

Tables showing the Half-Value (HVL) and Tenth-Value Layer (TVL) for penetration of x-rays and gamma rays through shielding material. The data is presented for broad beam conditions with heavily filtered x-rays and for gamma radiation. Despite its age (1971 vintage) may of the values are recognisable today, appearing in modern IAEA / NCRP radiation shielding data. Use with caution (and speak to a Radiation Protection Adviser).

  • Half-Value Thickness and Tenth Value Thickness for Heavily Filtered X-Rays in Broad Beam conditions Table 4.8 (1)
  • Half-Value Thickness and Tenth Value Thickness for Heavily Filtered Gamma Rays and Bremsstrahlung in broad beam conditions Table 4.8 (2)

Half-Value Thickness and Tenth Value Thickness for Heavily Filtered X-Rays in Broad Beam conditions Table 4.8 (1)

Half-Value Thickness and Tenth Value Thickness for Heavily Filtered X-Rays in Broad Beam conditions Table 4.8 (1)
Half-Value Thickness and Tenth Value Thickness for Heavily Filtered X-Rays in Broad Beam conditions Table 4.8 (1)

Examples for everyday use

In the preceding sections of this handbook presentation we established the following which is recognised in modern radiation shielding literature.

  • The TVL value for 150 kV x-rays was 1 mm lead.
  • The TVL value for 10 MV linac x-rays was 38 cm in standard density (2.35) concrete. (This is the TVLe, equilibrium value).

The values above were taken off the transmission curves shown earlier in this resource. It can be seen that the values are essentially the same as those presented in the above table.

Half-Value Thickness and Tenth Value Thickness for Heavily Filtered Gamma Rays and Bremsstrahlung in broad beam conditions Table 4.8 (2)

Half-Value Thickness and Tenth Value Thickness for Heavily Filtered Gamma Rays and Bremsstrahlung in broad beam conditions Table 4.8 (2)
Half-Value Thickness and Tenth Value Thickness for Heavily Filtered Gamma Rays and Bremsstrahlung in broad beam conditions Table 4.8 (2)

Examples for everyday use

In the above table, TVT and TVL (and HVT and HVL) are the same quantity)

In the preceding sections of this handbook presentation we established the following which is recognised in modern radiation shielding literature.

  • The TVL value for Co-60 in lead was shown to be 4 cm.
  • The TVL value for Cs-137 in lead was shown to be 2.2 cm.

The values above were taken off the transmission curves shown earlier in this resource. It can be seen that the values are essentially the same as those presented in the above table.