Continuing the sequence design, a calculation is performed to determine the location of the absorber by calculating the length of the cavity Eq. (26) and the spacing of the absorber (Sp) with respect to the focal point Eq. (27), as observed in Fig. 2. The radiation is distributed best on the absorber surface with a cavity length of 5.72 cm and a spacing of 20.86 cm to comply with this condition, because the projection cone image is taken after the focal point.