Synchrotron radiation, with its remarkable properties and eminent suitability for scientific and technical applications, is having a profound effect on the many disciplines that make use of radiation in the x-ray and vacuum ultraviolet regions of the spectrum. Indeed, the rapidly increasing availability of this radiation is revolutionizing some fields and is leading to a variety of new interdisciplinary collaborations. Seeking to take advantage of this incisive tool, scientists around the world are requesting time at synchrotron radiation facilities in such large numbers that the fast-paced construction of new sources—including several in less-developed countries—has yet to bring the level of availability up to that of demand.

In May 1981, PHYSICS TODAY devoted a special issue to synchrotron radiation research. Four articles reviewed facilities, applications and the then newly developed wiggler and undulator sources. In the intervening two years there have been very significant changes in the nature and availability of synchrotron radiation sources. Five new facilities have begun operation, and a similar number of facilities already in operation have undergone major expansions. The nature of synchrotron radiation research has also changed significantly, as have our expectations. Consequently, PHYSICS TODAY will publish a series of articles describing these changes in detail.

At a number of construction sites around the world, crews are laboring in and around large circular tracks to install the accelerators and storage rings that will form the basis of new synchrotron radiation facilities. Most of the budding facilities are designed to produce synchrotron radiation, in the soft- or hard-x-ray regions, that is far brighter than available sources can provide. They are sometimes described as the "third generation." According to this rough categorization, the first generation consists of circular accelerators originally intended for other purposes: They provide synchrotron radiation to parasitic experiments or, in some cases, they have become partially dedicated to such uses. The second generation comprises facilities specifically designed to support synchrotron radiation experiments, with the radiation produced primarily as electrons or positrons curved in the field of the machines' bending magnets. The third-generation machines, by contrast, are designed to optimize the radiation that is produced as the electrons or positrons traverse devices known as wigglers and undulators. The new machines will complement existing facilities, and they will provide more opportunities for the growing user community.

Willlibald Jentschke, founder and the first director of the German Electron Synchrotron (DESY) laboratory and a former director general of CERN, died peacefully on 11 March 2002 in Göttingen, Germany.

TODAY NEW DISCOVERIES in physics are rapidly assimilated. Although only nine years have passed since Rudolf Mossbauer submitted his first article, the Mossbauer effect is currently being used in many undergraduate physics laboratories, and four or five manufacturers are offering off-the-shelf Mossbauer spectrometers.

During the final weeks of World War II in Europe, as Allied armies swept across a chaotic, battle-torn Germany, two teams of the world's leading nuclear scientists were desperately at work. One team, sequestered in the New Mexican desert, hastened to assemble the atomic bombs that would shake the world later that summer. The other team, a group of Nazi-sponsored physicists and technicians in southern Germany, struggled to do something that, unbeknownst to them, the Allies had done two years earlier: build a critical, self-sustaining nuclear reactor.

Meanwhile, a different kind of team was running its own race against time. Convinced (erroneously) that the Germans were close to creating their own superweapon, the Allies sent an American unit of scientists, soldiers, and secret agents established by Lieutenant General Leslie R. Groves into Nazi Germany. Their orders: find the German scientific team before they could provide Hitler with atomic power. The scientific head of the mission: a Dutch-American physicist named Samuel A. Goudsmit. The mission code name: Alsos.

As his small entourage moved closer to the German research camp, Goudsmit revisited familiar people and places now changed forever by the war. The first Allied scientist to interrogate the captured physicists, Goudsmit heard first hand about life in a Nazi Germany in which they had lived and worked for over a decade. Most importantly, as the last person to review German nuclear research papers before military classification barred them from the public eye, Goudsmit was uniquely qualified to answer the most puzzling question: why, after their spectacular early successes, did German nuclear research efforts fall so miserably? Goudsmit's insights into the errors and hindrances that frustrated the German scientists, as well as his penetrating character analyses, remain uncannily accurate, as proven a half-century later by the now de-classified documents.

Online information resource for all things Mössbauer.

I explore the fifty-year development of Mössbauer spectroscopy by focusing on three episodes in its development at Argonne National Laboratory: work by nuclear physicists using radioactive sources in the early 1960s, work by solid-state physicists using radioactive resources from the mid- 1960s through the 1970s,and work by solid-state physicists using the Advanced Photon Source from the 1980s to 2005. These episodes show how knowledge about the properties of matter was produced in a national-laboratory context and highlights the web of connections that allow national laboratory scientists working at a variety of scales to produce both technological and scientific innovations.

The experiments which established the existence of naturally and artifcially radioactive emissions of negative and positive electrons by atomic nuclei and the critical calorimetric experiments which showed that part of the energy released during a P-decay process escapes in some yet undetected form were completed before 1933. In that year there was introduced the currently accepted picture of the P-process, in which Pauli's neutrino hypothesis occupies a central position. The assumption is that in the process a nucleon is transformed from a proton into a. neutron (or vice versa) with the simultaneous creation of a, positron (or negatron) and an (anti) neutrino. The latter particle is hypothesized to be the carrier of the missing energy and the failure to detect it after its emission is ascribed to its having no charge, probably no magnetic moment, and only small non-electromagnetic interactions with other particles.

Plans for the greatest laboratory of its kind for research into the fundamental forces that hold the universe together and into the mysteries of the vital processes of life were unfolded yesterday by a group of leading atomic scientists at the first conference to be held in the Brookhaven National Laboratory for Atomic Research, Brookhaven, L.I.