Design Of An Optical Fiber X-Ray Dosimeter Based On Different Scintillating Material

The number of the patients who have had cancer is keeping increasing in recent years.As an efficient treatment approach to treating cancers,radiotherapy has attached wide range of concerns.Radiotherapy can prevent tumor cells from division and proliferation using the way of radiation.However,if the cancer patient absorbed too much radiation during radiotherapy,it will be very harmful for his?her?health,the patient's healthy tissue will be damaged.In order to eliminate this negative effect,it is extremely important to invent a kind of X-ray dosimeter which can place inside the patient's body.In this paper,a kind of X-ray dosimeter which can measure the absorbed dose of the cancer patient in-vivo and in real time is presented.The dosimeter used the way of embedding scintillating material inside the plastic optical fiber core to detect X-ray.In the other side of the optical fiber attaches a photon counter and eventually received by a computer.This kind of dosimeter has the advantages of small size,flexibility and anti-electromagnetic interference,make it is able to put inside the patient's body to measure absorbed dose.In order to make the dosimeter mentioned above have better performance,five different scintillating materials were proposed to fabricate the dosimeter's probe parts.Their emission spectra have been measured.Furthermore,an evaluation of the dosimeter's performance has been made by analyzing the signal intensity emitted from the scintillation material.The dosimeter's linearity with the change of dose rate is also measured.Moreover,this paper also investigated how to use two different scintillating materials simultaneously to ensure the radiation area location,solving the problem of lack of water equivalence of inorganic fluorescent materials.The results show that the dosimeter embedded with Gd₂O₂S:Tb has the best performance,and using Gd₂O₂S:Tb and CsI:Tl can simultaneously can measure the radiation place and absorbed dose of the cancer patient.