Measurement of electron-calcium ionization integral cross section using an ion trap with a low-energy, pulsed electron gun

An apparatus for production of various atomic and molecular ions inside a linear Paul trap has been set up. The system applies a custom-made, low energy, pulsed electron gun to produce ions in electron impact process. Such ionization method can find some interesting possible applications such as derivation of ions inaccessible other-ways, which can be used in molecular ion experiments. The technique allows also for determination of cross sections for various collisional processes. As a feasibility study, the apparatus was used for determination of ionization integral cross section of calcium in the 16--160 eV range of electron impact energy. The obtained cross section values are discussed and compared with existing data sets.