Upgrading the Argonne 4-Mv Dynamitron

Recently a new type of accelerator tube,1 made entirely of ceramic and metal and containing no organic material, was installed in the Argonne 4-MV Dynamitron.2 Instead of being cantilevered from the base of the accelerator as was the old tube, the new tube is suspended from the main frame by a set of compact springs of unique design. Consequently, the main frame had to be strengthened against sidewise sway. The new structural members also markedly increased the shear strength of the frame. Previously ion-source assemblies were mounted directly on and their weight supported by the accelerator tube. Now the weight of each source is carried by the terminal frame, and provisions have been made for aligning each source to the tube. To provide space for a new source assembly which incorporates mass analysis, various electronic circuits within the terminal were relocated and the terminal wiring was rerouted. The accelerator has performed well since the modifications.