Theoretical and experimental investigation of dose enhancement due to charge storage in electron-irradiated phantoms

摘要: Recent measurements have shown that significant errors in radiation dosimetry can arise by the use of insulating plastic phantoms which been exposed to electron beams. The effect has attributed generation large electric fields phantom charge storage causing alteration trajectories and an increase measured dose. In this report, we examine hypothesis theoretically calculating change response ion chamber a cylindrical cavity electron-irradiated polymethylmethacrylate phantom. field distribution is determined using model allows for leakage radiation-induced conductivity, dose Monte Carlo simulation EGS (electron gamma shower) code modified account field. theoretical results are agree well with new previously published experimental enhancement data. agreement taken as confirmation reported explanation effect. conducting advocated.