A simple ion source for H₃⁺ions and molecular rare gas ions

A simple ion source producing H 3 + and different molecular rare gas ions is described. To stabilize the extracted ion current the discharge current is stabilized by regulating the gas flow. With hydrogen the extracted ion current consists of more than 95% of H 3 + ions. Thus a primary mass selection is not needed. In rare gases the content of molecular ions rises to about 1% to 4%.