Institute History

The Institute of Nuclear Physics from its foundation until today

The history of the Institute of Nuclear Physics was and is characterized by three essential factors, which only in combination make its history a success story:

  1. the constant, visionary and worldwide unique further development of accelerator technologies
  2. the realization of various high-precision experiments to study the nuclear constituents and their interactions
  3. the close cooperation and thematic interlocking between the experimental and theoretical working groups

The basis for the successful realization of all construction and research projects has also been, from the very beginning, the support of politicians, university decision-makers, and financial sponsors, such as the German Research Foundation (DFG), which has approved several special research areas for the research work at the Institute of Nuclear Physics since the 1980s:

  • SFB 201 "Medium energy with electromagnetic interaction" 1982-1998 (Spokesperson: Dieter Drechsel; later: Thomas Walcher)
  • SFB 443 "Many-body structure of strongly interacting systems" 1999-2010 (Spokesperson: Thomas Walcher; later: Dietrich von Harrach)
  • SFB 1044 "The Low Energy Frontier of the Standard Model: From Quarks and Gluons to Hadrons and Nuclei" 2012-2020 (Spokesperson: Achim Denig and Marc Vanderhaeghen)

Facts and figures in a nutshell

1957 Formal foundation of the Institute for Nuclear Physics (KPH) under Herwig Schopper as its first director.
1961 Hans Ehrenberg is appointed director of the institute
1964 Topping-out ceremony of the accelerator building and start of construction of a linear accelerator for electrons
1967 First electron beam of the linear accelerator
1971 The appointment of Dieter Drechsel and shortly thereafter that of Hartmuth Arenhövel establishes theoretical nuclear physics research at the Institute
1975 First proposal for the realization of a racetrack microtron (RTM) by Helmut Herminghaus
1979 First electron beam of the prototype RTM (MAMI A1) with 14 MeV final energy
1983 Completion of the first RTM expansion stage (MAMI A2) with 183 MeV final energy; Subsequently, start of experimental operation with MAMI A.
1989 Approval of the construction of an experimental hall for the installation of three large magnetic spectrometers to perform coincidence experiments (today's A1 experiment);
Cessation of operation of the linear accelerator
1991 Establishment of the energy tagging technique on the A2 experiment.
1992 After the departure of Helmut Herminghaus, Karl-Heinz Kaiser takes over as head of the accelerator group; Completion of a source for polarized electrons.
1993 Installation of a facility for coherent X-rays in the X1 experiment under Hartmut Backe.
2001-2006 Construction of the third extension MAMI C in the form of an HDSM (harmonic double-sided microtron) with 1.5 GeV final energy; Subsequently, start of experimental operation with MAMI C.
2002 Transport of the Crystal Ball detector from New York to Mainz. Subsequent installation at MAMI.
2003-2008 Installation and modification of the KAOS spectrometer in the A1 spectrometer facility for the investigation of so-called strange hadrons.
2008 MAMI reaches 100,000 operating hours since 1991
2008 Installation of a computer cluster for simulations in the context of theoretical physics
2010 Start of the conception of the electron accelerator MESA by Kurt Aulenbacher and Andreas Jankowiak; from 2013 design of first prototypes within the framework of the Cluster of Excellence PRISMA.
2018 Award of the JGU Medal of Honor for Helmut Herminghaus and Karl-Heinz Kaiser
2020 Laying of the foundation stone of the CFP I building for MESA
2022 Start of the establishment of MESA within the framework of the excellence cluster PRISMA+.


Since the end of the eighties, the Institute of Nuclear Physics has been presided over by alternating managing directors - some of them in several terms of office. In the order of their first term of office, these are:

Prof. Thomas Walcher, Prof. Dietrich von Harrach, Prof. Helmut Backe, Prof. Jürgen Arends, Prof. Josef Pochodzalla, Prof. Achim Denig, Prof. Concettina Sfienti, Prof. Niklaus Berger