| 摘要 |
PURPOSE:To improve the ionization efficiency by irradiating two laser beams having such wavelength as causes resonant light excitation from the bottom energy level to automatic ionizing condition onto aluminum vapor. CONSTITUTION:Aluminum vapor 10 to be ionized is led into a container 1 while two laser beams B3, B4 are led through the windows 3a, 3b to perform resonant excitation of vapor 10 from the bottom level to two electron exciting condition through 3,440Angstrom beam B3 in an ion producing space 4 at the crossing section while to perform resonant excitation in step into automatic ionizing condition through 3,050Angstrom beam thus to bring into an ionizing condition with predetermined transition probability and to take out as an ion beam 9 composed only of aluminum under D.C. voltage between an electrode 6 and a specimen table 8a to be irradiated onto a specimen 8. Consequently, the ionization efficiency and the selectivity of ion can be improved considerably. |
