纳米尺度上CR-39径迹蚀刻动力学研究

Study of track development kinetics for CR-39 detectors in nanometer size

在对CR-39探测器蚀刻6 h后发现照射区域与未照射区域的体蚀刻速率明显不同,因此用传统的几何模型无法正确得到几何量和物理量之间的对应联系。本文在以往辐射粒子固体径迹研究基础上,利用新的AFM观测手段得到纳米尺度的CR-39三维蚀刻径迹坑,并对探测器蚀刻几何模型进行了修正,提出了新的蚀刻速率比:V′=Vt/Virr对几何模型中各个参数进行计算。用修正的几何模型对100 MeV的Si离子的AFM观测结果进行分析。研究表明,100 MeV Si离子的径迹蚀刻速率:Vt=4.12μm/h,Virr=2.55μm/h,V′=1.62,Si离子入射角度为61.03°。同时我们通过局部覆盖法和台阶仪,得到本实验用CR-39的体蚀刻速率Vb=1.58μm/h。两者结合得到100 MeV Si离子的蚀刻速率比:V=2.61>V′。本研究采用传统的几何模型方法经过合理修正应用于新的观测手段,并得到了纳米尺度上蚀刻动力学关键参量。

In our previous experiment on CR-39 detectors,we found out that bulk etch rate of irradiated area is different from unirradiated area.Therefore,the traditional etching model should be revised.In this case,our modification which based on the theoretical studies printing out and the AFM observation was put forward and new etch rate：V′=Vt/Virr was defined.Then,modified track-diameter kinetics was used to clarify AFM analysis.In this research,the key parameters for 100MeV Silicon ion include Vt=4.12μm/h,Virr=2.55μm/h,V′=1.62,θ=61.03°.And the bulk etch rate Vb=1.58μm/h.So the etch rate can be calculated whose value is V=2.61V′.