Friedrich Arnold "Fritz" Bopp (27 December 1909 – 14 November 1987) was a German theoretical physicist who contributed to nuclear physics and quantum field theory.
In 1944, when most of the KWIP was evacuated to Hechingen in Southern Germany due to air raids on Berlin, he went there too, and he was the Institute’s Deputy Director there.
Bopp did not get along with them and described the initial French policy objectives towards the KWIP as exploitation, forced evacuation to France, and seizure of documents and equipment.
This incident caused tension between the physicists and spectroscopists at the KWIP and within its umbrella organization the Kaiser-Wilhelm Gesellschaft (Kaiser Wilhelm Society).
Other members of the Nuclear Physics Working Group in both 1956 and 1957 were: Werner Heisenberg (chairman), Hans Kopfermann (vice-chairman), Walther Bothe, Wolfgang Gentner, Otto Haxel, Willibald Jentschke, Heinz Maier-Leibnitz, Josef Mattauch, Wolfgang Riezler [de], Wilhelm Walcher, and Carl Friedrich von Weizsäcker.
The reports were classified "Geheime Reichssache" ("secret", the highest German classification level at the time), they had very limited distribution, and the authors were not allowed to keep copies.
The reports were confiscated under the Allied Operation Alsos and sent to the United States Atomic Energy Commission for evaluation.