In the duoplasmatron a hot cathode low pressure gas discharge is run under the confinement by an intermediate electrode and axial magnetic field in the anode region

and a highly concentrated low temperature plasme is formed. We used the radiation from the plasma as a VUV radiation source. The paper mainly discusses the construction the discharge mechanism and the spectra radiation of the source developed in our laboratory. The radiation wavelength of this source is shorter then 100nm and its stability and repeatability is better than 0.5%.