Ion sources are of practical importance for scientific research and industrial applications. The developed ion sources are used for evaporation on single crystals. We present in this research the construction and the optimisation of a low-energy ion radiation source. Which supplies a high ion current density using a cold cathode with low power. The physical aspects and the different possibilities for resolution of the problem are discussed with investigations on the parameters of the developed Duoplasmatron source. The conception is achieved by experimental investigations on selected construction versions. We show an interesting experimental results concerning the relation between the pressure and volume of the hollow cathode. The results are compared to those obtained by mass spectrometry at Penning and glow cathode ion source.