waiting to be used as a klystron. plines will be needed en route to new that it has taken some fifteen years One of the most interesting talks acceleration techniques. to demonstrate the abilities and limi­ was from Tom Weiland on a two- How to move ahead was the sub­ tations of the electron ring accelera­ beam scheme developed together ject of an evening discussion. With tor concept. Some of the exotic with Gus Voss and called a wake the big high energy physics Labo­ ideas presented at the Conference field accelerator. It involves an in­ ratories feeling financial pressures could require much longer investiga­ tense ring of electrons accelerated in and obsessed with the requirements tion. an outer aperture surrounding a cen­ of their immediate projects, it is not Above all it is necessary to encou­ tral tube where the desired beam is easy to envisage the liberation of rage young physicists to work on to pass. Fields generated by the pas­ money and manpower to pursue these challenging problems. It was sage of the ring percolate through 'way-out' ideas for the distant fu­ rather strange that new acceleration slots and create high accelerating ture. But some investment will be techniques were being discussed by gradients at the central tube (which necessary in the big Laboratories to an audience of experts whose aver­ can be envisaged to go as high as take advantage of their broad tech­ age age was probably over fifty, and 600 MeV/m). Also the reflected nological support. This sort of sup­ it was probably no coincidence that wave could be used to accelerate port is not available at most universi­ the liveliest papers were given by the particles of the opposite charge. ties. youngest participants. There is much When considering the length of to be done, there is probably some The Conference brought together time which would be needed to sift beautiful physics and engineering to physicists from the fields of lasers through the different possibilities be encountered and there is the goal and plasmas as well as the large con­ and, hopefully, to push one or two of of making it possible in the next cen­ tingent of accelerator specialists. It them to the point of practical use, the tury to continue the adventure of un­ seems likely that a much closer inter­ distant future may not be all that derstanding the nature of matter. mingling of these different disci­ distant. Dennis Keefe pointed out 25 years of Nordita

Nordita — the Nordic Institute for Theoretical Atomic Physics — this year celebrates its twenty-fifth anniversary. Its premises (left) are adjacent to the Institute.

(Photo C. Hansen)

Thisyearthe Nordic Institute for The­ oretical Atomic Physics — Nordita — in Copenhagen celebrated the twen­ ty-fifth anniversary of its founding. The institute reflects a great scien­ tific tradition, and continues to pro­ vide an important focus of research for physicists from the Nordic countries. Nordita owes its existence to a his­ tory of close collaboration among Nordic physicists. As a result of the

CERN Courier, December 1982 407 One of Nordita's earliest Directorate meetings: seated from left to right, J. Holtsmark, I. Waller, G. Funke, S. Rosseland, H. Wergeland and N. Bohr: standing, O. Klein, A. Bohr, J. Lindhard, E. Hylleraas, J. B0ggild, L. Nielsen, C. M0ller, S. Rozental and P. Jauho.

influence of Niels Bohr in his epoch- years, the idea of a Nordic institute the guidelines for the future estab­ making studies on atomic physics in for theoretical physics was much lishment of Nordita. Although initially the 1920s and 1930s, the Institute discussed. The development of only , Norway and Sweden for Theoretical Physics of Copenha­ these ideas went hand in hand with took part in the negotiations, there gen University (later to become the the establishment of CERN. An early were high hopes that Finland and Ice­ ) had a strong proposal by H.A. Kramers in the Ne­ land would collaborate. Nordic flavour from its inception in therlands that CERN be located at The proposal was well received in 1921. Copenhagen, and the offer of a site Denmark and Sweden, but despite After the upheavals of the Second by the Danish authorities, received strong support from Norwegian the­ World War, a high priority was given strong support from Norway and oreticians, the situation in Norway to investment in the natural sciences. Sweden. When the final choice of was complicated because of the in­ Among the Nordic countries, there Geneva was made, the Nordic repre­ terests of atomic energy. was a strong desire to develop the sentatives at CERN — Torsten Gus- During the establishment of CERN, tradition of cooperation in atomic tafson and Egil Hylleraas — ap­ it was decided provisionally to set up physics and the peaceful uses of proached Bohr with a proposal to go the CERN theory group in Copen­ atomic energy. In 1945, Sweden of­ ahead with the plans for a Nordic the­ hagen for five years (1952-57). fered to subsidize the establishment oretical institute. Further decisions on the Nordic Insti­ of an international institute for theo­ The negotiations which were to tute were postponed until plans were retical and applied nuclear physics, lead to the establishment of Nordita clearer on the CERN theory front. which it wished Niels Bohr to lead. began at a meeting early in 1953 at Each year the CERN Member Despite its appeal, this project could Goteborg in Sweden, at which a States selected a young theoretician not be realized due to strict secrecy committee was set up comprising to participate in the group under Niels surrounding information on atomic Bohr, Gustafson, Hylleraas and S. Bohr and which included Christian energy. Rozental. Soon this committee was M0ller, Aage Bohr, Gunnar Kallen, During the immediate postwar able to present a proposal containing Ben Mottelson and Stefan Rozental.

408 CERN Courier, December 1982