Ion source.

摘要

An EHD ion source according to this invention has an extractor (4) and a control electrode (11). The extractor (4) is disposed below a tip (2) and functions to apply an electric field to a substance (3) to-be-ionized wetting a pointed end of the tip (2), so as to derive ions from the pointed tip end. The control electrode (11) is disposed in the vicinity of the pointed end of the tip (2) and functions to apply an electric field to the substance (3) to-be-ionized in its molten state so as to supply the pointed tip end with the substance (3) to-be-ionized in a suitable amount.

As a result, a great ion current (5) which is substantially proportional to an extracting voltage (6) can be derived from the pointed tip end.