Can a Penning ionization discharge simulate the tokamak scrape-off plasma conditions?

The tokamak scrape-off (the region between the vacuum vessel wall and the magnetically confined fusion plasma edge), represents a source/sink for the hot fusion plasma. The electron densities and temperatures are in the ranges 10¹¹-10¹³ cm⁻³ and 1-40eV respectively (depending on the size, magnetic field intensity and configuration, plasma current, etc.). Relatively low charge states of various impurities are formed here in a variety of atomic and molecular processes. Since it is very difficult to study these processes in situ, we looked for a way to simulate them under conditions similar to those of the tokamak scrape-off layer. In the work reported, the electron temperature and density have been estimated in a Penning Ionization Discharge by comparing its spectroscopic emission in the VUV with that predicted by a collisional radiative model. An attempt to directly compare this emission with that of the tokamak edge is briefly described.