CALCULATION OF EFFECTIVE ENERGY ABSORPTION RATIO

It has been considered to be difficult to calculate the energy quantity, which is transfered to photons composing materials from incident photons, by means of present absorption coefficients. The ratio of transfered energy to photons composing water layer from incident photons (effective energy absorption ratio) was calculated theoretically. Consequently, the ratio of total exit energy to total incident energy as a function of thickness of layer was represented a sigmoid curve on semilogarithmic scale, and was saturated to the value of energy emerged from the layer by back scattered photons. It can be able to calculate the effective energy absorption ratio for given photon energy and for given thickness of layer by following equation, which is a function of photon energy and "effective energy absorption ratio coefficients" (k, n), obtained from the graphs. (effective energy absorption ratio) =1-k×E^n (E : primary photon energy [keV])