Gamma-Ray computational ghost imaging based on rotational modulation method

A 137Cs point source with an energy level of 0.662 MeV was utilized as the gamma-ray source. The internal cavity of the lead chamber is a rectangular space measuring 40 cm\u00d7 5 cm \u00d75 cm. Five sides of this cavity are fully shielded by lead bricks, while the sixth side remains open toward the detector. The emitted rays exit through an opening in the lead chamber, pass through a single-striped plate, and are subsequently detected. The NaI(Tl) detector features an outer diameter of 9.5 cm with a 3-inch effective diameter for the central scintillation crystal, the effective imaging area of the detector is 50 \u00d750 mm\u00b2.Consequently, the effective imaging window of the system is defined as a square area measuring 50 \u00d7 50 mm. The sub-coding plate is composed of 20 mm-thick stainless steel plates fixed onto a hollow rotating platform.An imaging resolution of 16\u00d716 pixels was employed in the experimental setup, so the single-stripe coding plate has a width of 3.125 mm for each slit. As specified in Chapter2, the rotational modulation scheme theoretically requires 16 distinct stripe plates, each rotated by 180\u00b0. In practice, however, full sampling can be achieved with only 8 plates, as each plate can be rotated 360\u00b0 and the stripe patterns\u2019 symmetry is exploited.