Professor Willibald Jentschke, the founding father of DESY, was appointed Professor of Physics at Hamburg University in 1955. In this position, his aim was to establish a first-rate facility of high energy physics in Germany, leading to the foundation of DESY in 1959.
Until the end of 1970 he was head of the DESY Directorate. From 1971 to 1975 he was Director General of CERN, the European Laboratory for Particle Physics. After his retirement he maintained an active interest in particle physics, and in DESY and CERN, until his death in 2002, shortly after his 90th birthday. His wisdom, his vision and his great personality in guiding DESY will always be remembered.

Professor Willibald Jentschke

Willibald Jentschke

Professor Dr. Dr.hc Willibald Jentschke was born in Vienna in 1911, and got his Ph.D. in 1935 with a thesis under Professor G.Stetter on a subject in nuclear physics. He then continued to work on nuclear physics at the University of Vienna.
  In 1939, he published a very important and topical paper with the title 'Ueber die Uranbruchstuecke durch Bestrahlung von Uran mit Neutronen' (On the fragments of Uranium from irradiating uranium with neutrons).

After the war he was invited to the US, where he became Professor at the University of Illinois in Urbana and, 1951, director of the Cyclotron Laboratory.

After 1955 research in nuclear physics (which included high energy physics) was again allowed in the Federal Republic of Germany. Accordingly, attempts were made to bring research on these subjects in Germany back to an international standard.

In the search for personalities who could help to make a new start, Jentschke was an obvious choice, since he had already made a reputation for himself in Vienna and later in the US.

When the University of Hamburg offered a chair of physics to him in 1955, he found a positive climate for supporting research in general and to his idea to build a new institute of physics around a modern particle accelerator. However, the actual scope of his vision far exceeded what the Hamburg officials were accustomed to. He demanded a sum of 7.5 Million DM, a fantastic sum at that time, and quite outside the the normal possibilities of the 'Freie and Hansestadt Hamburg'. It is a great tribute to Professor Jentschke's scientific vision, his competence, his enthusiasm and his ability to communicate these qualities, that he succeeded after long and patient negotiations to have this sum granted to him. It turned out to be the seminal funds for the construction of DESY, the 'German Electron Synchrotron'.

A great help in deciding the all important question of which accelerator to build was provided by an international accelerator conference at CERN in 1956. There Jentschke met with German colleagues, who were already active in accelerator building at CERN and at German universities. There was agreement, that there should be a concentrated German effort at one site, able to compete internationally, and complementary to the program of CERN. These requirements led to a plan to build a large electron accelerator, and Hamburg was an obvious choice for the site.

Such a machine could obviously not be built with the funds of the State of Hamburg alone. After long and tedious negotiations with the federal government and the German States (Laender), finally a financial agreement was reached and signed on Dec. 18, 1959. This date is the official founding date of DESY. Prof. Jentschke became the first director of DESY, a position he held until he became the CERN DG in 1971.

The role of Prof. Jentschke in these decisive years cannot be underestimated. His enthusiasm, his optimism, his tenacity in following his vision and his skill in negotiating with the authorities and in finding allies must have been very impressive.

Even before the official founding date he had started with the design of the laboratory, making it his own personal project, and working with a small group of devoted people. This early initiative was wery important, because, among other things, it gained time in building the laboratory.

When the financial and administrative difficulties had come close to a solution, Prof. Jentschke could turn to equally important questions of physics and research policy.

Firstly, it was decided to build an electron synchrotron and not a linear accelerator. With this decision DESY could still hold its own against the competition of the Stanford Linear Accelerator, which was built somewhat later and had a superior beam energy.

Secondly, Jentschke supported with great determination a policy which opened DESY, with favorable conditions, to outside users from the German universities and from the Max-Planck society. Actually, the German Universities were included into the process of long range scientific planning. This policy, which emphasised the service function of DESY, proved to be a decisive advantage for the future, because it attracted talent from all over Germany and somewhat later also internationally. Actually, long before international cooperation became a catchword, Jentschke supported the participation of scientists from outside Germany. This was the beginning of a gradual opening of DESY to international use, which was to become so important for the future.

Building the 7.5 GeV electron synchrotron was a very difficult task, because there was very little experience available in Germany. Jentschke succeeded to enlist a team of young and enthusiastic physicists and engineers, who took up the challenge. A key ingredient to their success was the spirit of teamwork, which Prof. Jentschke created, and his great human qualities in his leadership. Unselfish help was given by Professor Livingston, who at the same time was constructing the Cambridge Electron Accelerator, in competition with DESY. Help came also from CERN, where H.O.Wuester spent some time to get advice on the optics of the machine. And so the DESY synchrotron delivered its first beam on Feb. 26, 1964. The figure shows Prof. Jentschke bringing a toast Drs. Degele, Kumpfert and the synchrotron team in the DESY controll room on that memorable day.

DESY delivers the first beam

DESY delivers the first beam

Establishing an experimental program for the electron synchrotron was another critical task which was on Prof. Jentschke's shoulders. Again, this was a field in which very little experience existed in Germany. Jentschke succeeded to recruit a first team of young experimental physicists from inside and outside Germany- his charm and enthusiasm went far in persuading people to come to a new laboratory, with an accelerator still in building. He approached the German universities to send teams to Hamburg, and he encouraged international collaborations right from the beginning.

Under the leadership of Prof.Peter Staehelin and Prof.Martin Teucher the experimental program took a successful start. S.C.C.Ting's work on testing QED gave DESY an early recognition. Naturally electron- proton scattering was one of the key research activities. Teams led by Friedhelm Brasse, Herwig Schopper and Gustav Weber could soon present data which were second to none. Photoproduction was the other large part of the program. There, results achieved with a polarised photon beam from a diamond target won the prestigious Physikpreis of the German Physical society for a team of young physicists in 1970. A hydrogen bubble chamber, built at Saclay, covered the subject of more complex photoproduction reactions. The figure shows Prof.Jentschke and Prof. Teucher together with the bubble chamber team at the inauguration of the bubble chamber in the DESY experimental Hall 1.

Inauguration of the DESY bubble chamber

Inauguration of the DESY bubble chamber

Subsequently a comprehensive program on photoproduction was carried out with the chamber. The collaboration also included a team from the then DDR, not a trivial thing in those times.

In addition to high energy physics Prof. Jentschke recognized the potential of research with synchrotron radiation right from the beginning, and supported it strongly. This initiative was another one of his visions, which was to become very important for the future. His vision was shared by Professor Staehelin, who, as Director of Research, was the driving force for establishing a successful research program in synchrotron radiation. This early initiative led eventually to Hasylab, the large synchrotron radiation laboratory at the DORIS storage ring. The key people in this development are shown in the following photograph. They cover the development of the synchrotron radiation activities from the original 'Haenselbunker' at the Synchrotron to the big expansion coming with the DORIS storage ring. It brought important outside users like IBM, the Max Planck Society and EMBL, and finally led to the foundation of Hasylab. The figure shows some of the leading personalities in the development of synchrotron radiation at DESY.

Leading personalities of synchrotron radiation research at DESY

Leading personalities of synchrotron radiation research at DESY, from left to right: Prof.R.Haensel, first Ph.D.Student of Prof.Staehelin, later Professor at Kiel University and former director of the European Light Source; Prof.P.Staehelin, first DESY director of research; Prof.J.Schneider, presently DESY Director for research with synchrotron radiation; Prof.B.Wiik; Prof. K.Holmes,initiator of the EMBL outstation at DESY; Prof. Ch.Kunz, first Hasylab director and former director of the European light source; Prof.W.Jentschke; H.Berghaus, former administrative director of DESY; Prof.G.Materlik, former director of Hasylab, and now of the Diamond Light Source.

It seems that Professor Jentschke was well ahead of his time in many important respects. Decades before the word 'outreach' was coined, he saw to it, that the work of DESY was communicated to the public; there were 'open days' at DESY for the neighbors, articles in popular magazines, and there was the beginning of a PR group. There were many beneficial effects from this; as an example good relations with neighbors proved later very important when DESY had to expanded beyond its original site to build HERA.

A few years after the successful start of DESY the question of the next project posed itself. The choice was an electron- positron storage ring or a bigger electron- synchrotron. This was not an easy decision- at that time. These were pre- quark times, and many people thought that the main research activity of storage rings would be measurement of the proton form factor in the time-like region and testing QED, and that beyond a few GeV no interesting physics could be done. On the other hand, physics with the electron synchrotron had been so far quite successful and many people wanted to have 'more of the same'. On this vital question Prof. Jentschke carried out the widest possible consultations, but did not receive an unambiguous picture. In the end, Prof. Jentschke sided with the argument 'to make something new', and put his weight behind the storage ring project. In retrospect, this was a decisions which was a great tribute to his vision in physics and to his wisdom.

During the construction phase of the DORIS storage ring, Prof. Jentschke made a seemingly minor decision by choosing the magnets somewhat larger than absolutely necessary- necessary for the physics as it was then understood. This change enabled the storage ring to go to higher energies than originally forseen, and proved to be the entrance ticket for the very successful program of b-physics. But this was to come much later.

In the fall of 1974 the storage ring started to work. The time coincided with the discovery of the J/psi particle, and allowed DESY to participate in the very front line of research. The storage ring decision also improved the research potential in the field of synchrotron radiation dramatically, which again would have very important consequences for the future. Prof. Jentschke could not witness this period of great successes of DESY personally, because he had accepted the post of Director General of CERN in 1971. The figure shows him on his birthday together with Prof.W.Paul and Dr.H.O.Wuester.

Prof. W. Jentschke on his birthday

Prof. W. Jentschke on his birthday,
together with Prof. W. Paul and Dr. H. O. Wuester

He was Director General of CERN Laboratory I from 1971 to 1975. His time at CERN was highlighted by the successful operation of the Intersecting Storage Rings (ISR), and above all by the discovery of weak neutral currents by the Gargamelle Collaboration, one of the most important achievements at CERN.

After his return to Hamburg, he spent a sabbatical year at the Stanford Linear Accelerator SLAC. There he participated in a very important experiment, demonstrating the presence of weak parity violation in electron-proton scattering, and he could make important contributions due to his intimate knowledge of oldfashioned classical physics.

In the later years, after his retirement from the University of Hamburg, he kept an active interest in physics and in the DESY laboratory, having been elected a honorary member of the DESY Scientific Policy Committee. He spent his birthday at DESY, meeting with many people, who wanted to congratulate him, and having a look at DESY's new research facilities. He passed away soon after, in March 2002.

Needless to say, without Jentschke DESY would not exist. His singular devotion to the cause of physics, his vision and wisdom in taking key decisions and the trust and appreciation he enjoyed with the authorities, all these qualities enabled him to create DESY and to shape the future of the Laboratory in the best possible way. But still, this is not the complete story. Equally important was his great personality. It encompassed knowledge, competence, vision, Viennese charm, and courage. He had the talent to recognize and attract excellent people and to encourage fruitful and engaged teamwork. With his example and his authority he created what could be called the spirit of DESY, emphasising teamwork and the appreciation of the work of others, fairness and putting the good of science and of the laboratory above personal ambition. This spirit is still there, and in this sense Willibald Jentschke is still with us - to the good of the laboratory.


- based in part on an article in the CERN Courier-


Prof.W.Jentschke - Distinctions

Member, Akademie der Wissenschaften u. Literatur, Mainz
corr. Member, Akademie der Wissenschaften, Wien
Hon. Doctor's Degree, University of Illinois
Hon. Doctor's Degree, RWTH Aachen, 1990
John T.Tate Award of the American Institute of Physics, 1996