Government, parts of the old Reichsanstalt were established in Braunschweig. The idea for this re-founding had been developed by the former PTR advisor for theoretical physics, Max von Laue, already during his internment in Farm Hall. In 1947, he succeeded in convincing the British authorities to make the former Luftfahrtforschungsanstalt (Aeronautical Research Institute) in Völkenrode near Braunschweig available to the PTR successor. In 1948, Wilhelm Kösters, who had been the director of Division 1 in Berlin for many years, became its first president. Many former PTR employees from Berlin, Weida and Heidelberg followed him to Braunschweig. The new institute was named ꞋꞋPhysikalisch-Technische AnstaltꞋꞋ (PTA) and, since 1 April 1950, ꞋꞋPhysikalisch-Technische BundesanstaltꞋꞋ. In 1953, the West Berlin PTR was integrated into this institute as ꞋꞋBerlin InstituteꞋꞋ while respecting the four-power status of Berlin. In the German Democratic Republic (GDR), the Deutsches Amt für Maß und Gewicht (DAMG) had established itself with its principle seat in Berlin. After several renamings, this institute was designated Amt für Standardisierung, Meßwesen und Warenprüfung (Office for Standardization, Metrology and Quality Control – ASMW) during the last GDR years; the name already indicates that this office of the GDR had more extensive tasks than PTB in the Federal Republic of Germany (FRG), namely additional tasks in the field of standardization and quality assurance and in the area of activity of the Bundesanstalt für Materialforschung und -prüfung (BAM). Growth and reunification The young PTB grew rapidly in the years after its founding – both in terms of staff and in terms of financial resources. Not only its scientific metrological profile was extended, but also its palette of services rendered to industry, in particular in the form of calibrations of measuring instruments. In the 1970s, this led to the founding of the Deutscher Kalibrierdienst (German Calibration Service), which delegated service tasks to accredited, privately run laboratories and allowed PTB to concentrate itself on more demanding measurement tasks. From 1967 to 1995, PTB operated the Experimental and Research Reactor Braunschweig. This reactor served in particular as neutron source for fundamental research, not for the investigation of nuclear energy. PTB dealt with this controversial subject from 1977 to 1989, above all due to the fact that the task "long-term management and disposal of radioactive waste" had been assigned to it. Later on, this field of work passed over to the ″Bundesamt für Strahlenschutz″ (Federal Office for Radiation Protection) after same had