Both NaI(Tl) and BGO can be used as PET detectors. The linear attenuation coefficient of BGO at 511 keV is 0.964 cm−1 as opposed to 0.343 cm−1for NaI(Tl). BGO does not convert gamma ray photons to light photons as efficiently as NaI(Tl), and is in fact roughly 13% as efficient. In this problem, suppose two detectors are designed, one from NaI(Tl) and one from BGO. Assume both are designed to stop 75% of the 511 keV photons that strike the crystal.
(a) Find the detector thicknesses for NaI(Tl) and BGO.
(b) A light burst from NaI(Tl) has a higher intrinsic SNR than that from BGO. Find the ratio of intrinsic SNRs, NaI(Tl) to BGO.
