Answer Happy

5.22 A hypothetical x-zube has been designed. An x-ray burst from this tube yields cxactly 104 x-ray photons at cnergy E1 = 60 keV and 105 X-ray photons at energy E2 = 65 keV. = C In the following parts of this question, assume that the above x-ray tube is used as a source in an imaging system to image a phantom, as shown in Figure P5.4. In addition, make the following simplifying assumptions: • Assume a parallel beam of x-rays that are uniformly distributed over an extended source. • Assume that the x-rays passing through the phantom undergo the photoelectric effect only; that is, neglect the effect of Compton scatter. 2 cm A 1 cm 16 ed Az А, B Thc phantom consists of three arcas A1, A2, and A3, as labeled. The lincar attenuation coefficients pl1, H2, H3 (units of cm-?) of these three areas at the energy levels present in the x-ray bcam are given in the table below. E EZ 41 12 3 0.2 0.3 0.5 0.4 0.1 0.4 (b) Draw the total number of x-ray photons per cm that hit the detector as a function of position x. (c) Assume the x-ray intensity is proportional to the number of photons. Calculate the contrast of the image observed at the detector as a func- tion of position x assuming that A is the target and B is the background.