Life and Work of Rolf Wideröe by © Pedro Waloschek,     => Contents

Box 9:  Betatrons in Germany

The late Professor Wolfgang Paul (University of Bonn), a pioneer of particle physics and high energy accelerators in Germany, who was awarded the Nobel Prize in 1989 for the development of the `ion-trap', described Germany's War-time betatron projects in 1947 [Pa47]. He mentioned Wideröe's and Steenbeck's work and the developments subsequent to 1941:

"Kerst's success meant that work on betatrons, as Kerst later named his machine, was also resumed in Germany. The construction of such an electron accelerator was approached from a total of four different directions. At the forefront of the betatron builders' intentions was the exploitation of fast electrons or their X-rays for medical-therapeutic purposes and for testing materials. Use of the betatron as a research instrument for physics was considered of secondary importance. There were projects by K. GUND at the Siemens-Reiniger-Werke, Erlangen, prompted by STEENBECK for machines of 6 and 25 MeV; further by WIDERÖE for 15, 100 and 200 MeV, by BOTHE and DÄNZER for 10 MeV and by GANS and SCHMELLENMEIER for 1.5 MeV. Of these, GUND's for 6 MeV and WIDERÖE's for 15 MeV were completed by 1945, whereas the others did not progress beyond planning or only went as far as the construction of the magnet-systems."

Paul then goes on to describe the two successful machines by Gund and Wideröe in detail and to compare them.

As Professor Paul further reports [Pa93], he and his tutor Hans Kopfermann also wanted to build a betatron in Göttingen. However, when they heard about Gund's project they offered their assistance to Siemens and were able to conduct first experiments with the 6 MeV betatron (then 5 MeV) in the spring of 1944 in Erlangen. During the American occupation in 1945, an order to dismantle the betatron had been issued, but Paul and Kopfermann succeeded in preventing this with the help of the British Military Government. In 1947 they were able to transfer the betatron to Göttingen where they and others used it for several nice experiments [Gu50]. They also succeeded in extracting the electron beam [Gu49].

This betatron has been an exhibit of the Smithsonian Institution Museum in Washington since the 1960s.