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离子束修形(IBF)技术成为光学零件获得超高面形必不可少的加工工艺.修形过程中采用光阑获取小的束径、稳定的去除函数是获得超高面形精度的前提.不同材料和工艺参数等不同条件下获得的去除函数都不相同,每次修形前都要重新测量去除函数.研究了不同入射能下、不同靶距下以及有无光阑时去除函数的变化.发现在离子光学系统几何参数一定的条件下,离子束去除函数的效率变化与入射能量、离子体浓度引起的离子鞘形状、束散角、温度、靶距、净加速电压与总加速电压之比的变化等因素都有关.当增大入射能量时,去除效率随之增加,但当入射能量大于一定值后就会出现随着入射能量增加而去除效率降低的“拐点”现象.有无光阑只改变去除效率的大小而不会改变“拐点”现象.因此不选用入射能量增大而去除效率减小的“拐点”之后的入射能量修形.
Ion Beam Boring (IBF) becomes an indispensable processing technology for obtaining ultra-high profile of optical components.It is precondition to obtain ultra-high profile accuracy by using aperture to obtain small beam diameter and stable removal function. The removal functions obtained under different conditions such as different materials and process parameters are different, and the removal function must be remeasured before each modification.Research on the removal function under different incident energies, different target distances and with or without stop It is found that the ion beam removal efficiency and incident energy under the certain geometrical parameters of the ion optical system, the ion sheath shape, the beam divergence angle, the temperature, the target distance, the net accelerating voltage and the total accelerating voltage caused by the ion concentration Than when the incident energy is increased.When the incident energy is increased, the removal efficiency increases, but when the incident energy is greater than a certain value, the “inflection point” phenomenon with the decrease of the incident energy will appear. Aperture only changes the size of the removal efficiency without changing the “inflection point” phenomenon. Therefore, we do not choose the incident energy modification after the “inflection point” where the incident energy increases and the removal efficiency decreases.