1973 Multi-ampere duopigatron ion source
US 3740554 A

Inhalt: Erzeugung eines Ionenstrahls mit hoher Ionendichte

ZUSAMMENFASSUNG
A duoplasmatron ion source is modified to provide a large plasma surface with a uniform density at a target cathode.
The target cathode and the acceleration and deceleration electrodes are gridded or multi-apertured and are spaced in close proximity each to the others with the apertures being in alignment.
With such an arrangement, it is possible to extract multi-ampere bright ion beams at energies of tens of KeV.
Conversion of the ion beam to a neutral particle beam can be readily accomplished by addition of a gas cell.

https://www.google.de/patents/US3740554
Von: Morgan O, Atomic Energy Commission


2. Referenz zu Tabellen Der Elektronen Ionenphysik and Ubergikroskopie by M. Von Ardenne, (VEB Deutscher Verlag der Wissenschaften, Berlin, 1956)