The table-top model MHD generator is pretty easy to build. There are numerous heat and conducticity losees due to its simple construction. You should look at this as an opportunity to vastly improve upon its design and consequently its power power output.
Figure 2 illustrates the construction. Two large ceramic magnets are self supported using three steel plates, see parts list. The self-supporting magnets for a chamber where the electrode is positioned. A small base-board supports six wire electrodes. The electrode height is matched to the burner height of the torch used. The electrodes are wired as shown in Figure 3. The use of segmented electrodes produces a greater electric output than a single large electrode.
Figure 8-4 shows a simple seeder unit that seeds the gas with potassium nitrate.