I remember Juan Roederer (see his article in Physics Today, January 2003, page 32), his wife, and newborn child quite well from their 1953 visit to the Max Planck Institute for Physics in Göttingen, where I was working toward my PhD under Werner Heisenberg. Even though I had heard the sensational news that Argentine scientist Ronald Richter had achieved controlled fusion, I never asked Roederer what he knew about the project. Through Wolfgang Meckbach, who later became the director of the Bariloche research center and who married my cousin, I got a much better insight into Richter’s work. My understanding differs substantially from Roederer’s account. Putting together the different pieces, I got the following picture.

Primarily through the work done in Germany on electric arcs, Richter likely had known that, with the water-vortex—confined arcs (Gerdien arcs), temperatures of ~50 000 K had been achieved, still much too low for thermonuclear reactions to take place. But he also must have known that with plasma resistivity dropping rapidly as temperature rose, resistive heating alone was insufficient to reach the necessary high temperatures. To overcome that problem, he proposed—for the first time, I believe—using ion-acoustic heating by surrounding an arc with many powerful loudspeakers that focused intense sound waves on the arc. To reduce the heat conduction losses into the surrounding medium, he placed the arc in a strong axial magnetic field. That temperatures of 100 000 K can be reached by that technique was later rediscovered by scientists from the Max Planck Institute for Plasma Physics in Munich. So what went wrong with Richter’s project?

First, although he was apparently quite familiar with electrical discharge physics, Richter must have been unfamiliar with nuclear physics. Second, he did not, or was not permitted to, publish his research. Had he published, the US likely would have declassified its controlled fusion research much earlier. Richter’s work was not far off from what was done in the US, and some of his ideas—like ion-acoustic plasma heating—were actually new. Third, Roederer says that the Argentine scientists sought the opinion of Karl Wirtz, a codirector of the Max Planck Institute for Physics, rather than asking such outstanding physicists as Fritz Houtermans, who reportedly had left the institute because Wirtz was difficult to get along with and knew little about plasma physics.