PURPOSE: To enable an ion beam to be stably led out without causing any positional shift of a needle-like tip resulting from its thermal expansion by fixing the needle-like chip of a liquid metal ion source to the heater by the surface tension of a molten ionization substance.
CONSTITUTION: Firstly, an ionization substance 2' is placed on the reservoir 4' of a heater 3' which is located near the pointed end of a needle-like chip 1' fixed to a connection bar 10 by means of a joint 11. Next, after a current is fed to the heater 3' to melt the substance 2' and moisten the surface of the chip 1', heating is stopped to solidify the substance 2' with the chip 1' penetrating the substance 2'. After that, the chip 1' is separated from the pointed end of the chip 1' and then heated by feeding a current to the heater 3', thereby leading out an ion beam from the pointed end of the chip 1'. As a result, the chip 1' is fixed to the heater 3' by the surface tension of the molten substance 2' to be ionized, thereby enabling the chip 1' to stably operate for a long time without causing any positional shift or breakage of the chip 1'.
KAWANAMI YOSHIMI
ISHITANI TOORU
TAMURA MASAO
