摘要 |
PURPOSE:To greatly improve the ionization efficiency and the ionic specificity of an ion beam generator by resonantly exciting the ionization substance to a Rydberg state immediately before ionizing the substance. CONSTITUTION:Beryllium vapor 10 is introduced into a case 1 through a gas introduction hole 1a and voltage is applied across electrodes 5 and 6. As the result, electrons produced by gas electric discharge strike the beryllium vapor 10 to excite it to a metastable state. Next, light (B3) radiated by a synchrotron is introduced into the case 1 through a slit 1c to resonantly excite the beryllium vapor 10 to a Rydberg state. After that, the excited beryllium vapor 10 is ionized by electronic impacts caused by gas electric discharge. D.C. voltage is applied across an electrode 6 and a sample base 8a and the ionized beryllium vapor 10 is irradiated upon a sample 8 as an ion beam 9 consisting of beryllium ions alone. |