DEPTH OF PENETRATION OF RADIATION ENERGY. After reading this section you will be able to do the following: Explain why radiation penetrates deeper into some materials than it does others. Define half-value layer and how it can be used to compare the radiation absorption characteristics of a material. Penetration of Gamma rays. Gamma rays are the most penetrating of the radiations. Gamma rays are highly energetic waves and are poor at ionising other atoms or molecules. It cannot be said that a particular thickness of a material can absorb all gamma radiation. Many centimetres of lead or many meters of concrete are required to absorb high levels of gamma rays.
Consequently, the penetration depth of alpha particles is very small compared to the other radiations. For low density materials, the range 2 of 5.5 MeV alphas (from Am-241) is between 4.5 - 5 mg/cm2; higher density materials give a range between 5 and 12 mg/cm2. The table below gives some specific values. Ionizing radiation takes a few forms: Alpha, beta, and neutron particles, and gamma and X-rays. All types are caused by unstable atoms, which have either an excess of energy or mass (or both). In order to reach a stable state, they must release that extra energy or mass in the form of radiation. Alpha Radiation.
They hold the highest power of penetration. They are the most penetrating but least ionizing and very difficult to resist them from entering the body. The Gamma rays carry a large amount of energy and can also travel via thick concrete and thin lead. Apr 24, 2017 · The phonons in a material will absorb radiation over a larger bandwidth than the atoms alone. As Bob S stated, the penetration of high energy waves actually increases with shortening of wavelength. The absorption properties of a material will greatly vary over the frequency range.
Penetration depth is a measure of how deep light or any electromagnetic radiation can penetrate into a material. It is defined as the depth at which the intensity of the radiation inside the material falls to 1/e (about 37%) of its original value at (or more properly, just beneath) the surface. The penetration power of an x-ray beam is determined by its voltage and is expressed as kilovolt peak (kVp). As kVp increases, so does penetration. Known as Quality of the Beam. Can also affect quantity The penetration power of an x-ray beam is determined by its voltage and is expressed as kilovolt peak (kVp). As kVp increases, so does penetration.