Consider a linear 2D compound parabolic concentrator built from parabolas tilted at 10^◦ to the vertical, with a trough of width 3 m, and an absorber width of 0.5 m. Compute the concentration C of the concentrator. If the incoming radiation has intensity I₀ = 1000 W/m² and the (blackbody) absorber is kept at a temperature of 100 ^◦C by circulation of a thermal fluid, compute the rate of energy transfer to the fluid. Compare this rate of energy transfer to that for a linear parabolic concentrator with the same absorber area and acceptance angle; assume that the parabolic concentrator has height equal to the focal length (as in Example 24.4), and that the absorber has an area covering the lower half of a cylinder centered on the focal line, and is kept at the same temperature of 100 ^◦C.