| 摘要 |
The invention provides an electron impact ion source for the generation of multiply- or super-highly-chared ions including an electron gun with cathode and anode for the creation and acceleration of electrons, a device for the axial-symmetric focussing of the electron beam, a device for introducing ionisable substances into an ion trap, which may be opened and closed, in the region of the axial-symmetric focussed electron beam, a device for destroying the electrons after they have passed the ion trap, and a device for creating a vacuum around the axial-symmetrically focussed electron beam and the ion trap within said beam. The device for the axial-symmetric focussing of the electron beam comprises at least two ring structures radially magnetized in opposing directions and each of these ring structures enclosed the electron beam. The two ring structures radially magnetized in opposing directions are connected by magnetic conductors to form a unified magnet system, whereby the closing magnetic field passes the ion residence zone in the ion trap. The cathode has a very high emissivity of >=25 A/cm<2 >with a small cathode diameter. A vacuum of from 10<-7 >to 10<-11 >Torr in the ion residence zone can be set while operating the electron impact ion source. |
