Co Irradiation Chamber

Due to its excellent remote measurability and high spatial resolution, the fiber optic-based radiation dosimeter has been extensively explored for its usability in medical applications by several researchers [1-2]. In the previous work [3,4], we reported the result of our investigation on feasibility of a photon dosimeter constructed with a BGO(Bi4Ge3O12) or GSO(Gd2SiO5) scintillator piece coupled to a plastic optical fiber. The plastic optical fiber had a diameter of 3mm and the scintillator piece was in a cylindrical form with 5mm diameter. The size of the scitillator piece as well as the fiber should be as small as possible for higher spatial resolution, and the radiation hardness should be high enough for stable operation in strong radiation fields. Recently, LYSO(Cerium-doped Lutetium Yttrium Orthosilicate) scintillators, which have much higher light yield and radiation hardness than BGO and GSO, have been commercially available. This paper reports the result of our investigation on dosimetric characteristics of a fiber optic-based dosimeter employing a smaller LYSO scintillator piece with 2mm diameter coupled to a silica optical fiber with 1mm core diameter.