5. A tungsten-anode x-ray tube is operated at a kVp setting of 120 kV, a tube current (Itube) of 1.3 mA, and an exposure time (texp) of 0.9 sec. (a) Calculate the deposited power Pa and the radiated power Pr. What is the x-ray production efficiency of the tube at these settings? (b) The number of electrons hitting the target is approximately #e ~ (I tube X texposure) / (1.6x10-19 - ) . How many x-rays are produced? (c) What voltage is required to achieve 50% efficiency with tungsten (all other settings the same)? What element (Z) is required for at least 50% efficiency at 120 k Vp