| 摘要 |
<p>A charged particle beam source which can be used both as an electron source and as an ion source has a tip 1 formed of a carbide, nitride or di-boride of at least one of Ti, Zr, Hf, V, Nb and Ta or of a hexa-boride of at least one of the rare earth elements of atomic number 57 to 70. Switching means (8, 9, 10) enable simultaneous change of the polarity of the tip (1) relative to a first electrode (11) and of the first electrode (11) relative to a second electrode (12). </p> |
