Beryllium Cathode Needs Final TouchesMay 31, 2017
While we had expected to receive the beryllium cathode in mid-March, the part did not pass Hardric Labs’ internal inspection. The machining tool had inadvertently bounced off the bottom of each of the 16 vanes that are the main parts of the cathode, creating tiny nicks on the neighboring vanes. Since the machining process is entirely automated, and this occurred during the last step of machining, this problem was not found until inspection. With the help of Rudy Fritsch, LPPFusion’s Chief of Investor Relations and a highly experienced mechanical engineer, the LPPF team came up with a fix that smooths off the nicks and may even improve the cathode’s performance. The fix requires a custom machining tool, so some additional delay in the part’s completion is expected. However, the beryllium cathode will be crucial to the next set of experiments, so getting it right is worth the time. The nicks would have created sharp surfaces that could concentrate the electric current and possibly disrupt the filaments that are needed for high performance.
Since beryllium is a very light atom, with only four electric charges, we expect none of the impurity problems we have had with earlier materials. The effect of impurity ions on the plasma is proportional to the square of the atomic charge, so beryllium has 300 times less impact on the plasma, ion for ion, as tungsten. At the same time, the tungsten experiments will allow us to start the beryllium experiments with a close-to-optimized preionization system, so our continued tungsten experiments will contribute to the success of the beryllium series.