| With the development and wide application of nuclear technology,the dose monitoring for application of nuclear technology has received more and more attention.Being able to reflect the damage degree of the irradiated person,the biological dosimeter has an irreplaceable effect that physical dosimeters and chemical dosimeters do not have.However,existing biological dosimeters still have the disadvantages of narrow range of applicable doses and large analytical workload.In view of the shortcomings of existing biological dosimeters and the need of developing new dosimeters,this paper developed a novel wide-range biological dosimeter based on the radiation damage effect of proteins,and studied the dosimeter response under gamma and carbon ion irradiation.The main research results are as follows:(1)The influencing factors of assessing film response with flatbed scanner were studied,and a method of measuring the dose of protein solution based on Gafchromic film was established.2000 dpi was chosen as the best scanning resolution,which has a near Gaussian pixel-value distribution without multi-peak problems.By changing the focus setting,the relative standard deviation of pixel values of Gafchromic film was reduced by 36% to 50%.To avoid the influence of scanning position and film inhomogeneity,scanning the same film before and after irradiation at the same position was recommended.Control the scanner's operating temperature at 15 ~ 24 °C to obtain stable response.A standard operating procedure for assessing the film response was proposed,significantly reducing the 95% confidence interval for the film calibration curve.By selecting suitable fitted dose range and the weighted average dose,the accurate measurement of the film dose is realized.Combining the film dose and the dose conversion factor,the protein solution dose was measured.(2)The response relationship between protein damage degree and protein type,irradiation dose,solution concentration and dose rate was established,and response research on the biodosimeter based on the radiation damage effect of protein for gamma radiation was completed.As the exposure dose increases,the damage degree of protein increases,and different proteins have different response modes.The greater the concentration of the protein solution is,the more difficult it is to degrade.The dose measurement from 2.3 to 2555.7 Gy is achieved by changing the solution concentration of the bovine serum albumin.In addition,the dose rate also affects the radiation damage effect of proteins,and the protein damage is smaller at the high dose rate.(3)The response research on the new dosimeter for carbon ion radiation was studied,and compared to that under gamma radiation.The uniformity of the dose distribution under carbon ion irradiation was demonstrated by the Monte Carlo simulation.The response modes for protein damage induced by carbon ion radiation vary for different protein species,and the response modes for the same protein are also different compared to that under gamma irradiation.Comparing relationships between the damage degree of protein and the dose for carbon ion and gamma radiation,the difference between the carbon ion dose and the gamma dose was obversed when the damage degree of protein was same.A method to realize the dose measurement for mixed radiation field based on this difference was proposed.Finally,the dose depth curve,dose uniformity and radiation intensity required for experiments for neutron and proton radiation were studied by Monte Carlo simulation,completing the design of radiation field for protein damage biodosimeter research for neutron and proton radiation.In this paper,a wide-range biological dosimeter based on radiation damage effect of proteins is proposed,and it can not only measure the exposure dose of organisms,but also strengthen the research on radiation biological effect and damage mechanism,which is important for determining the biological effects and health assessment of subjects. |
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