Absorbing particles energy absorption

Rubber Content. In the theories of toughening where the role of rubber particles is (a) to absorb energy directly or (b) to induce matrix yielding through stress concentration or hydrostatic tension effects, energy absorption should increase linearly with the number of rubber particles (proportional to rubber content if particle size is invariant). On the other hand, if dynamic craze/crack branching is the operative mechanism, evidence of an exponential law may be expected. The exponential form of the law may be derived as follows. 

Similarly, for an absorbing particle initially at rest, when the photon is absorbed, the absorber will recoil. Then, the distributions of the emission and absorption energies are, consequently, separated by two times the recoil energy, 2ER (see Figure 1.42). In this case, the chance of resonant absorption is proportional to the overlap of both distributions. 

The reduction in intensity of a beam can occur by two mechanisms. One involves the deflection or scattering of the particles from the direct line of path between the source and the detector and is described by the scattering coefficient ii. The second mode of reduction is the complete transfer of the projectile energy to the absorbing material (the particles are "captured" ) and is designated by the energy) absorption co cient The (total) attenuation coefficient in (6.7) is the sum of both these modes. 

Consider Ax = l/p for a unit gram mass of material with an exposed frontal plane area of 1 cm , where p is the density of the absorbing substance in grams per cubic centimeter. Since E is the energy in millions of electron volts (Mev) per particle or photon of radiation, then the rate of energy absorption or dose rate is... 

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