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 | Mrs. Bakker and her children § | will be leaving Geneva on 17 | | August. When these lines appear, | Other People's Atoms | Professor Bakker's family will al- j | ready be back in the Netherlands. | This is the third article on high energy | The editor is sure that the | physics in the United States in 1959. The | whole staff of CERN will wish to | two previous articles appeared in the May and June issues of the "CERN | join the CERN COURIER in | COURIER". ] sending all best wishes to Mrs. | Bakker and her children and say- | | ing « Au revoir». 1 G. Kenneth Green is in charge of building the 30 GeV synchrotron at the Brookhaven Research Labo­ ratory in the United States. On 5 February last, referring to the inauguration of the 28 GeV CERN synchrotron, he said : "The energy range beyond 20 GeV seems very promising. We hope to join you there soon !" Giessen (Germany). He received the prize on 1 July at a ceremony comme­ They have. morating the 350th anniversary of the The following telegram arrived at CERN during University, whose Physics Institute was the night of 29 July : "We finally made it. Went directed by W. K. Rontgen until 1885. through half integral to thirty one". The prize will be awarded annually for Three official telegrams were sent off on the CERN telex : exceptional work in fundamental re­ • "Congratulations from all CERN on your success. Nice to have company" search on particle physics. from S. A. ff Dakin and G. Bernardini, in the absence of J. B. Adams. The scroll handed to Mr. Adams states © "Sincerest congratulations from the members of the PS Machine Group "the prize is awarded at the same time for your great success" from P. Germain. to all the scientists who under his direc­ ® "31 000 congratulations to you from us all. Best of luck in the next stages" tion have succeeded in this great ven­ from the Members of the Parameter Committee. ture in European co-operation". From the synchrotron Machine Group Two months — as in the case of CERN — after the first beam had been comes the news that it has obtained a once round the machine, the Brookhaven proton synchrotron is operating at beam current of 2.5 x1011 protons per full energy. This is wonderful news for the scientific world. pulse. The following figures may be of Two giant accelerators will now share in the study of the infinitely small. interest to the technicians: by 3 August A full programme can now be undertaken in cooperation. All physicists will the magnet of the big accelerator had be delighted at this, even though the title of "biggest in the world" has once been pulsed 2 286 500 times since it again crossed the Atlantic... • was commissioned. The electric power for the magnet alone reaches 3470 kvA. In the field of biq accelerators, the big Brookhaven synchrotron has come THE 194-INCH SYNCHRO-CYCLO­ riments relating to the scattering of into operation ; its energy reaches 31 TRON AT BERKELEY pi mesons from protons. The anal­ GeV ("BeV" in America). A new 100 ysis of these experiments promises GeV machine is apparently under consi­ Because of the heavy demand for to provide detailed information on deration in the States and may even experimental time on the 184-inch this fundamental process. have reached the planning stage. cyclotron at the Lawrence Radiation An experiment also has been European bubble chamber users held Laboratory, this accelerator was performed to study the production of a small "international conference" at placed on 3-shift, 24-hour-day ope­ an additional pi meson by the colli­ CERN on 17 June. The purpose of this ration early in 1959. The experimen­ sion of a pi meson with a proton. meeting was to assess the facilities tal physics programme at the cyclo­ The results of this experiment in­ available in Europe in the field of bub­ tron was concerned mainly with the dicate that a much greater number ble chambers and instruments for the study of the interactions and decays of pi mesons are created than had evaluation of photographs, to form a of pi and mu mesons. An intense been expected on the basis of prior committee for planning experiments and beam of positive pions or pi mesons, theoretical predictions. New theore­ to organize the bubble chamber expe­ has been formed at the 184-inch tical ideas which include effects of riments with the synchrotron. cyclotron in order to perform expe- interactions between the pi mesons are in reasonable agreement with experimental results.

ATMOSPHERIC NEUTRON SPECTRUM An experiment to study the at­ mospheric neutron spectrum and its relation to the Van Allen radiation See page 8.

Yuri Sherbakov, the third scientist, is an experimental physicist who has been attached to the Russian Centre of Dubna since 1953. At CERN he will take part in the exploitation of the 600 million elec- tronvolt (600 MeV) synchro-cyclotron. lie was born at Volsk on the Volga in August 1925. He was a student at the Moscow Institute of Technology and stu­ died physics under Professor Kosadev. He went to Dubna in 1953 and has been and since 1958 has been working at State University ivhere he obtained his working there for five years on the 680 Dubna, where among other work he has Doctorate in 1952. He then entered the MeV synchro-cyclotron. been studying the "field of application Dubna Nuclear Study Centre where his of Mandelstains representation". latest tvork was on the "Low energy Three European scientists will soon be Rostislav Ryndin also comes from Le­ bremsstrahlung from high energy elec­ sent to Dubna for six months in ex­ ningrad, where he was born on 20 Janu­ tron-proton collisions". Mr. Ryndin is change, but their names had not yet been ary 1920. He studied at the Leningrad married and has one child. announced when this article was written. 3