Speaker
Description
For focused ion beam applied to secondary ion mass spectrometry,reduced brightness related to beam current,beam size and energy spread is a key parameter to evaluate beam quality.An ion beam size measurement device with knife-edge sweeping method aimed to measure the diameter of 10μm scale has been developed.The device enables to measure beam current changes as a function of knife-edge position by cutting across ion beam with a spatial resolution of 1μm.The knife-edge movement controlled by a 1μm resolution servo motor is real-time measured by a 0.1 μm resolution grating ruler.For energy spread diagnosis, a retarding field energy analyzer has been developed and tested with negative oxygen ion beam.A cylindrical focusing electrode is used to make diverging ions parallel to the axis to improve the resolution.The primary experimental results show that the ion beam is of Gaussian distribution in the transverse direction,and the energy spread(FWHM)is about 21 eV when beam energy is 10 keV.
| E-mail for contact person | sunlt@impcas.ac.cn |
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