NASA's Advanced Composition Explorer (ACE) was launched on August 25, 1997, carrying six high-resolution spectrometers that measure the abundances of the elements, isotopes, and ionic charge states of energetic nuclei in space. Data from these instruments is being used to measure and compare the composition of the solar corona, the nearby interstellar medium, and cosmic-ray sources in the Galaxy, and to study particle acceleration processes in a variety of environments. ACE also includes three instruments that monitor solar wind and energetic particle activity near the inner Lagrangian point, "1.5 million kilometers sunward of Earth, and provide continuous, real-time data to NOAA for use in forecasting space weather. Eleven of the articles in this volume review scientific progress and outline questions that ACE will address in solar, space-plasma, and cosmic-ray physics. Other articles describe the ACE spacecraft, the real-time solar-wind system, and the instruments used to measure energetic particle composition.
This text presents fresh observational data and implications, providing new understanding of the present day problems. It also gives clues to the future directions of progress in the area of energetic particles in space.
The cosmic radiation was discovered by Hess in 1912 but its origin is still the subject of much controversy and considerable study. For several decades most workers in the cosmic ray field were interested in the Nuclear Physical aspect of the particle beam and many important dis coveries were made, notably the identification of the positron, the muon, the pion and the strange particles. More recently however, em phasis has changed to the Astrophysical aspect both with re8ard to the origin of the radiation and to its relation with the other radiation fields. Mindful of the increasing importance of the Astrophysical facets of the subject the Cosmic Ray Commission of IUPAP approached the High Energy Astrophysics Commission of the IAU with the suggestion of a joint Symposium on Cosmic Ray Origin. The plan was to bring together workers in all the various astronomical fields - from Radio, through Optical to Gamma Rays - with Cosmic Ray physicists and to fully explore the various interrelations. The approach was received with enthusiasm and this book contains the proceedings of the ensuing Symposium, (styled IUPAP/ IAU Symposium No. 94) which was held in Bologna from 11th - 14th June 1980. Virtually all the papers presented are reproduced here. The Scientific Organizing Committee chose the invited speakers whose papers formed the major scientific component of the meeting. Additional short contributed papers were also called for and very brief 2-page resumes (which have not been refereed) are given in the proceedings.
In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery.Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological and medical aspects of the cosmic radiation because of it ionizing character and the inevitable irradiation to which we are exposed. This book is a reference manual for researchers and students of cosmic ray physics and associated fields and phenomena. It is not intended to be a tutorial. However, the book contains an adequate amount of background materials that its content should be useful to a broad community of scientists and professionals. The present book contains chiefly a data collection in compact form that covers the cosmic radiation in the vicinity of the Earth, in the Earth's atmosphere, at sea level and underground. Included are predominantly experimental but also theoretical data. In addition the book contains related data, definitions and important relations. The aim of this book is to offer the reader in a single volume a readily available comprehensive set of data that will save him the need of frequent time consuming literature searches.
The 25th International Cosmic Ray Conference marked the golden jubilee of this series of conferences. Held under the auspices of the IUPAP Commission C4, it was hosted by the Space Research Unit of the Department of Physics of the Potchefstroom University for Christian Higher Education.The proceedings present the newest developments and highlights of cosmic ray production and propagation, the extragalactic realm now being explored using neutrino and gamma ray astronomy. These fields are strongly related to high energy physics.
