Who is who in CERN

Research Director Wolfgang GENTNER Synchro- Division The group of visiting scientists headed Wolfgang Gentner then returned to by Prof. A. Lagarrigue, from the Eco'k Germany where he became Prof. W. Polyfechnique in Paris, arrived at the Bothe's assistant at the Kaiser Wilhelm 25 GeV synchrotron on 1 July. Institute (now the Max-Planck Institute) The group is placing a large piece of in . There, he continued his experimental equipment weighing near­ work on gamma rays. In particular, he ly 100 ions in the synchrotron beam. determined their photonuclear effects on This is a propane-freon bubble chamber all the elements. For this work, he used measuring 1 x 0.5 x 0.5 m, installed in gamma rays at 17 MeV—the highest en­ time to take its first photographs on ergy gamma rays which had so far been 22 July and take part in a long experi­ obtained—produced by the reaction of ment on 8 and 9 August. After Prof. lithium when bombarded by protons B. Hahn's Group from the Swiss Univer­ at an energy of a million electronvolt. sity of Fribourg, which will take part In October, Prof. Centner will resign The protons were provided by a 1 MeV in experiments during the whole of I960, from his duties as Research Director of Van de Graaff electrostatic accelerator this is the second team of physicists the Synchro-cyclotron Division to be­ constructed by the young physicist. from the Member States to come and come Director of the Max-Planck Re­ At the beginning of 1939, Wolfgang work at CERN. It will help to exploit search Institute in Heidelberg. Born on July 23 1906 at -on- Gentner went to work for six months at the big synchrotron and the Organiza­ Main, Wolfgang Gentner chose to study Berkeley in the United States. He studied tion will benefit from its exploratory physics. In 1925, he went to the Univer­ the construction of with their measurements of the beam. sity of Erlangen, then completed his edu­ cation in 1930 at the University of Frank­ inventor E.O. Lawrence. At the Berkeley At the 600 MeV synchro-cyclotron, furt. The thesis which he presented ana­ Radiation Laboratory, W. Gentner also Prof. F.P.G. Valckx's team of physicists lyzed "the range of electrons in matter co-operated in Segre's work and further and their biological effects". (Utrecht University) has left CERN. This At that time, many students were at­ improved the gamma-ray laboratory. is the first team to have completed a tracted to biophysics : Wolfgang Gentner Science, it is said, knows no frontiers. series of experiments: these were on studied this science until 1933, working Wolfgang Gentner's "French period" prov­ "scattering of positive mesons by com­ as assistant to Prof. Dessauer at the Uni­ versity of Frankfurt. In particular, he ob­ ed this once again. The young German plex nuclei." scientist passed the first three years of served the effects of X-rays and cathode Prof. M. Converses Group from the rays on albumin. the war at the College de France. He University of Rome arrived on 13 June ; He left for Paris in January 1933. He ran the small 10 MeV cyclotron with it is performing an experiment with remained at the Radium Institute until Frederic Joliot. During these years, W. the SC on "the emission of elec­ the beginning of 1956, working with Ma­ Gentner's contribution to international trons by muon capture". Finally physi­ dame Curie until her death in 1934, and science was not only concerned with cists under Prof. B. Brix and Dr. Stalder, with the Joliot-Curies. Under their direc­ scientific matters but also political ones, from the Institute of Tech­ tion, his work was mainly concentrated as his nationality enabled him to ex­ nology, will do a counter experiment on the diffusion of gamma-rays includ­ tract some of his French colleagues— after 10 August in order to determine ing abnormal absorption of these rays and in particular F. Joliot—from some the "radii of heavy nuclei". and their absorption by different photo­ difficult situations. electric and Compton effects. He also In 1943, W. Gentner was recalled to Still at the SC an 85-ton magnet 6 m did research on photonuclear effects in Germany. At Heidelberg he built the cy­ long arrived on 7 July. At the be­ beryllium and on the production of pairs clotron for medical research at the Kaiser ginning of August measurements were of particles—it was at the time of the Wilhelm Institute. This accelerator, which made on the magnet and it was adapted discovery of the positron, "the positive is still in operation, produced 12 MeV to the requirements of the g -2 experi­ electron". deuteron beams or 26 MeV beams of al­ ment now being performed by a team pha particles. under F. Farley and R. Garwin. From 1946 to 1958, Wolfgang Gentner The Council met on 11 July and held the chair of physics at the Univer­ aprpointed Mr. J. B. Adams Director- sity of Freiburg-im-Breisgau. General until 1 August 1961. Further During this time, he also acted as details are to be found on page 10. Contents consultant to the Study Group for the The Director-General was awarded the CERN proton synchrotron which was then Rontgen Prize of Liebig University at • Prof. W. Gentner .... 2 under the direction of 0. Dahl. With A. • Last month at CERN ... 2 Citron, one of his former students, he • CERN - DUBNA exchange . 2 calculated the concrete and earth shield­ • Other people's atoms . . 3 ing, which at present stops any ionizing • What is CERN ? .... 4 radiation from the accelerator, as well as • CERN Building Sites ... 6 the mound between the accelerator and • Do you know that .... 8 CERN - DUBNA Exchange the French border. • Council 10 In 1955, the CERN Council appointed One of the items on the Agenda of the Professor Gentner Director of the Syn­ 16th Council Session (see page 10) con­ CERN COURIER» chro-cyclotron Division. On 1 October cerned an exchange of scientists between was founded in 1959 at the instigation 1958, he was appointed Director of the our European Organization and the So­ of Professor C.J. Bakker, Director-Gene­ Max-Planck-Institute in Heidelberg. This viet Centre of Dubna. ral of CERN. It is published monthly for the staff of the European Organiza­ post meant that he could only give part Three Soviet scientists arrived at Mey- tion for Nuclear Research and distributed of his time to CERN. He therefore re­ rin on 18 July for a period of six months, free of charge to members of the orga­ signed from his duties as Director of the during which they will co-operate in nization, scientific correspondents and anyone interested in problems connected SC Division but, as Director of Research, various aspects of the exploitation of the with the exploitation of particle accel­ continued to give part-time service to particle accelerators and in theoretical erators or in the progress of nuclear CERN. He also continued to co-operate studies. physics in general. in the selection of fellows: it was he who Who are these new colleagues ? Editor was responsible for initiating the CERN Roger ANTHOINE Two of the physicists, V. Meshcherya- Public Information Office, fellowship scheme. kov and R. Ryndin, are physicists from CERN. Geneva 23, Switzerland The Max-Planck Research Institute in the Theoretical Physics Laboratory at Tel : (022) 34 20 50 Ext. 788 Heidelberg, where Prof. Gentner will Dubna. They have naturally been attach­ Printed in Switzerland take up his duties in October, is one of ed to CERN's Theoretical Study Divi­ The cover photograph shows part of the CERN installations with the big 25 GeV the independent German research insti- sion, where they will continue work be­ proton synchrotron in the foreground. tut which are linked to the universities gun in the USSR before their departure. Insef, photograph showing the South side through their staff. Thus, while acting as Vladimir Meshcheryakov is the young­ of the South Experimental Hall, with the Director of the Institute, Prof. Gentner est: he was born on 20 September 1932 piping for evacuating propane, in the will hold seminars on at in Leningrad and graduated from Mos­ foreground. Heidelberg University. cow University in 1953. He is married 2