John A. Simpson
The General Assembly of the Centro Latinoamericano de Fisica (CLAF) held at Leon, Mexico, from 24 to 26 November 1999 with the representatives of the governments of ten Member States, Argentina, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, Mexico, Uruguay and Venezuela, in attendance has unanimously approved a declaration of support for the installation of new experiments in the historical Laboratorio de Fisica Cosmica de Chacaltaya. As a result of this declaration the Laboratorio de Chacaltaya assumes the position of an International Centre of High Energy Cosmic Ray Physics and Astrophysics, where it will be able to foster the installation and success of new experiments, carried out by international collaborations. The Chacaltaya site altitude corresponds to 5230 m (atmospheric pressure of 540 gr/cm2), at 16o S. Latitude (see also CERN Courier Nov. 2000.) A Meeting on Cosmic Ray Physics was organized at La Paz, Bolivia on Jul.23-27, with the aim to review the progress in Cosmic Ray Physics with special emphasis on applications in future experiments at this, the highest altitude laboratory in the world, and to discuss other experiments/observations in different fields that could profit by installation at this unique high altitude. About 110 delegates from 17 countries were in attendance (55 were from Bolivia) and 48 contributions in several fields in the cosmic ray physics were presented. The meeting was very impressive, pleasant and fully successful (see CERN Courier Jan/Feb 2001.)
Item Entered February 5, 2001
The 26th ICRC conference proceedings are now available online. You may
link to the
conference proceedings home page at:
Note: The Invited/Rapportour volumes have been shipped and attendees should be receiving them now.
Item Updated June 27, 2000
The 27th ICRC is scheduled for August 7 - 15, 2001 in Hamburg, Germany. Their WEB page is now up and running at:
March 16, 2001
June 1, 2001
June 1, 2001
July 6, 2001
Item Updated February 6, 2001
In addition to the well-established and successful Shakti P Duggal award for young researchers, the 26th ICRC saw the first presentation of the newly established O'Ceallaigh medal and the announcement of one further award, the Yodh Prize.
The O'Ceallaigh medal is awarded by the Commission for "Distinguished Contributions to Cosmic Ray Research" and commemorates the late Professor Cormac O'Ceallaigh (1912-1996) who was head of the Cosmic Ray Section of the Dublin Institute for Advanced Studies from 1953 until 1984. As a young man he spent a year working in the laboratory of Pierre Auger in Paris, but his most productive period began when he worked in Cecil Powell's group in Bristol in the late forties. During this period he did important work on what would now be called Kaon and neutrino physics using the nuclear emulsion technique. His subsequent work was mainly on developments of the solid state track detector technique for determining the ultraheavy element abundances in the cosmic rays, work which is just now coming to fruition with results being reported by his former colleagues at Salt Lake City from the DIAS/Estec Ultra-heavy Cosmic Ray Experiment.
The Commission had a difficult task in deciding to whom to award the first O'Ceallaigh medal. It is clear that when an award like this is first instituted there will inevitably be a number of excellent candidates who would probably have received the award in earlier years had it existed. In this case two names rapidly emerged from those suggested as clear favourites, both in their own very different ways excellent canididates. The Commission eventually decided that the correct course of action was to award the 1999 medal jointly to John Simpson from Chicago and George Zatsepin from Moscow. Between them they have made seminal contributions to essentially all areas of Cosmic Ray Research, from the solar and Geomagnetic effects studied with Simpson's neutron monitors to the ultra-high energy and probably extragalactic particles seen beyond the Greissen-Zatsepin-Kuzmin cut-off. Each has been an inspiration to generations of students and colleagues and it is fitting that their contributions be recognised formally by the community to which they have given so much.
Luke O'C Drury <firstname.lastname@example.org> Tel. +353-1-6621333
School of Cosmic Physics, Fax +353-1-6621477
Dublin Institute for Advanced Studies,
5 Merrion Square, Dublin 2, Ireland.
Item Entered February 8, 2000
John A. Simpson, a pioneer in cosmic ray physics and solar system exploration, died August 31, 2000 of pneumonia that developed following open-heart surgery. He was 83. At the time of his death he was the Arthur Holly Compton Distinguished Service Professor of Physics (Emeritus) at the University of Chicago, where he had been a faculty member since 1945. Although his health had declined steeply in the few weeks before his death, he continued to pursue his research until he entered the hospital in mid-August.
After receiving his A.B. from Reed College in 1940 and his Ph.D. from New York University in 1943, Simpson began his career as a scientific group leader for the Manhattan Project in Chicago, developing instrumentation for measurement of high-intensity radiation. After the war, he applied the techniques he had developed to the study of cosmic radiation, leading directly to his invention of the neutron monitor to measure atmospheric neutrons produced when cosmic rays impinge on the atmosphere. This became a standard instrument for study of cosmic ray intensity variations, and is still used throughout the world. In 1956, Simpson and his colleagues Eugene Parker and Peter Meyer used neutron monitor observations of the intensity profile of an increase in high energy radiation after a large solar flare to infer the existence of an extended region of magnetic fields around the sun in interplanetary space, a region we now know as the heliosphere. Defining the structure and scale of the heliosphere remains a prime focus of space physics research, and much of Simpsonís subsequent scientific career was involved in some way with exploration of the heliosphere and its effects.
At the same time that he was beginning his cosmic ray studies, Simpson was also deeply involved in efforts to retain control of nuclear energy in civilian hands, an effort that presaged his life-long commitment to formulation of responsible science policy. In 1945, building upon a weekly group seminar that he had organized during the Manhattan project to discuss international control of nuclear energy, he founded the Atomic Scientists of Chicago and helped to launch the Bulletin of the Atomic Scientists. Serving as its first chairman, he set the direction for this distinguished journal, which continues to advocate international weapons control and responsible application of science to world problems. In 1957-58 Simpson was one of 12 scientific organizers for the International Geophysical Year, which enlisted scientists from 68 nations, including, at the height of the cold war, the communist countries, in an effort to increase understanding of Earth and its environment. He also served from 1965-1967 as chairman of the International Commission on Cosmic Radiation, part of the International Union of Pure and Applied Physics which fosters international communication and coordination among scientists.
In his scientific studies Simpson was among the first to take the study of cosmic rays into space. His first space experiment was carried on the Explorer 6 Earth satellite in 1959, and over his career his instruments were carried on more than 30 space missions. While his investigations became increasingly sophisticated and wide ranging over the years, he continued to be personally involved in all stages, from instrument design to final data analysis. In 1962 he founded the Laboratory for Astrophysics and Space Research at the University of Chicago, where almost all of his instruments were designed and built, and where the flight results were analyzed as well. Many of his instruments incorporated new techniques or inventions that he developed and that later became widely used. In the mid-1980ís, when he was almost 70, he invented a completely new type of detector for high-velocity dust particles that opened a new direction for his research. These detectors have so far found application to studies of dust particles in space on five missions, including the Soviet Vega missions to comet Halley and the current Cassini mission to Saturn.
By the end of his career, Simpson had participated in the first flybys of Mercury, Venus, Mars, Jupiter, Saturn, and comet Halley, as well as the first explorations of the heliosphere beyond the orbit of Pluto and at high solar latitudes in the inner solar system. Still, his principal interest was focussed well beyond the solar system as he exploited his measurements for what they could tell about such fundamental astrophysical questions as the structure of the interstellar medium in the galaxy, the nature of the nucleosynthesis process that makes the chemical elements, and the way in which nature accelerates nuclei to the immense energies at which they are observed as cosmic rays.
Ultimately, John Simpson was a visionary. His gaze was always directed well beyond the horizons that constrained the vision of many of his contemporaries and coworkers. He was at the same time a practical scientist, who could work within the constraints of organizations, technological possibility, and political uncertainty to bring about realization of his goals. In recent years his main research effort has been based on his experiment on the Ulysses mission, which is making the first exploration of interplanetary space over the sunís poles. He began to advocate such a mission in 1959, long before it was technically possible. Throughout the following decades he continued to press for an out-of-the-ecliptic mission until, as the joint NASA/ESA Ulysses mission, it was finally successfully launched in 1990. His continuing efforts played a large part in development of the mission and in extending the operation of the mission to this day and on towards the next solar minimum. Similarly, even this past summer he was actively involved in defining instruments for possible future missions that may not reach fruition for a decade or more.
That was John Simpson. Although he had achieved most of his scientific goals, had won the most prestigious awards offered by the professional societies he belonged to, and was honored by membership in societies such as the National Academy of Sciences and the American Philosophical Society, he was never content with past success. To the end of his life he was always looking for the better measurements and the new discoveries to be made. He brought along a small army of students and colleagues on his journey, most of whom have continued as active participants in scientific research. His vision, his drive, and his enthusiasm for science will be sorely missed by all who had the privilege of knowing him and working with him.
More details on John Simpsonís life and career can be found on the web at http://ulysses.uchicago.edu/simpson.
Item entered Nov. 7, 2000
The eminent Russian scientist, Full Member of Russian Academy of Sciences, Professor of Moscow State University Khristiansen Georgy Borisovich passed away on August 4, 2000 at the age of 73.
He was born in Moscow on May 31, 1927. In1950 he graduated Moscow University . His scientific career was connected with Moscow University since 1953 after post-graduate study. In 1961 he became the head of the Superhigh Energy Particle Department of the Institute of Nuclear Physics of Moscow State University.
G.B.Khristiansen was one of the leading scientists in Cosmic Ray Physics and High Energy Physics. His fundamental contribution in these fields is well known to the world science community. He was the creator of large-scale arrays for Extensive Air Shower study at Moscow and Samarkand Universities, co-creator of the giant array in Yakutsk. G.B.Khristiansen proposed and developed new effective method for longitudinal development study of individual air showers based on measurement of Cherenkov radiation pulse shape, the method which soon became widely used all over the world.
While studying Extensive Air Showers he discovered a principle new phenomenon - a sharp change of the cosmic ray energy spectrum slope near 3.1015 eV (the so called "knee"). This result, confirmed by leading world laboratories, is one of great importance for Cosmic Ray Physics and Astrophysics.
The new method of primary cosmic ray mass composition study was also proposed by G.B.Khristiansen. This method based on measuring of the fraction in Extensive Air Showers made possible to reveal a change of the mass composition from dominantly light nuclei to a composition of heavier nuclei at energies higher than "knee" energy.
A series of well-known works of G.B.Khristiansen were devoted to the Radio Emission study of Extensive Air Showers and proof of its coherence and geomagnetic nature, to the scaling violation of hadron interactions at ultra high energies, and to an experimental proof of the existence of particles with energies 1019 - 1020 eV . G.B.Khristiansen was an initiator of the new giant Extensive Air Shower array construction (project EAS-1000).
In capacity as professor of Moscow University G.B.Khristiansen brought up several researcher generations. He was always a good friend and patient teacher for every newcomer to his field of science. G.B.Khristiansen was also a good organizer. During many years he was a deputy chairman of Cosmic Ray Council of Russian Academy of Sciences and a member of Cosmic Ray Commission of the IUPAP.
For achievements in cosmic ray investigation G.B.Khristiansen was awarded a Lenin prize - the highest prize of former Soviet Union. He was also awarded a M.V.Lomonosov prize and State prize of Ukraine.
The death of G.B.Khristiansen is a great loss for Cosmic Ray Science in Russia.
Yuri A. Fomin
Item entered Nov. 7, 2000