PIXE、SEM与切片技术相结合研究低能离子注入种子的浓度-深度分布

用质子激发X荧光分析和扫描电子显微镜与切片技术相结合对能量为 2 0 0keV的钒离子注入花生后的浓度 -深度分布进行了测定 ,注入剂量为 9× 10 16/cm2 。结果显示 ,钒离子注入花生后的浓度 -深度分布与离子注入金属、半导体中的分布有明显的差异 :离子的射程歧离很大 ,少数离子的射程延伸到很深的区域。这种分布特征可能与植物种子具有疏松的结构有关。

Measurement of low energy ion implantation profiling in seeds by the PIXE and SEM with slicing up technique

The mutation effect caused by low energy ion beam implantation into dry seeds has been accepted and turned into practical application.But its mechanism is still not clearly understood.According to the energetic ion range theory,ions with hundreds of keV energy can' t directly affect the nuclei of the cell inside the embryo part of the seeds underneath the thick seed coat.It is obviously important to measure the concentration-depth distribution of the implanted ions in seeds for study of the mechanism.200keV V+ ions were implanted into dry seeds of peanut with a dose of 9×1016ions/cm2,then the seeds were sliced up into 15μm thickness along the incident beam direction .The concentration of the V in each slice was measured with PIXE (Particle Induced X-ray Emission).It is shown that the concentrations of the V in un-implanted peanut are lower than the detection limit of PIXE.But the concentrations in the slices of implanted peanut up to 121—135μm depth are higher than the PIXE detection limit.More than 98% of V are in the first slice ( corresponding to 0—15μm depth),however,the rest part of V distribute over a wide depth range.This fact indicates that the structure in peanut seeds is not homogeneous,the implanted ions can reach a much deeper depth than that predicted by the range theory.