ISSN:0031-9228    

DOI:10.1063/1.2813691

出版商:AIP    

年代:1985

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2813692

出版商:AIP    

年代:1985

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2813694

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

Carlo Rubbia and Simon van der Meer of CERN share the 1984 Nobel prize in physics for “their decisive contributions to the large project which led to the discovery of the field particles W and Z, communicators of weak interaction.” In 1976 Rubbia and his collaborators had the idea of converting the Super Proton Synchrotron at CERN into a proton‐antiproton collider, where the W and Z particles could be created. In 1968 van der Meer had invented the method of stochastic cooling, which allowed the dense packing and storage of enough antiprotons to make the W and Z in pp¯ collisions. The CERN pp¯ collider project, the largest ever to appear in the context of the Nobel prize, yielded its first collisions in 1981. Two year later, in 1983, both the W and Z were observed by the UA1 detector group led by Rubbia and by the UA2 detector group. The Royal Swedish Academy of Sciences, in announcing the award, said, “Two persons in the CERN project are outstanding—Carlo Rubbia, who had and developed the idea, and Simon van der Meer, whose invention made it feasible.” This year's prize, which is worth about $193 000, is the first to honor work done at CERN.

ISSN:0031-9228    

DOI:10.1063/1.2813695

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

In an effort to highlight for government funding officials “areas in which incremental funding may lead to major advances,” a research briefing panel headed by Hans Frauenfelder (University of Illinois) and APS president Mildred Dresselhaus (MIT) conducted a series of briefings in Washington last Fall on “Selected Opportunities in Physics.” At the request of the President's Office of Science and Technology Policy and the NSF, the panel had selected emergent fields of physics research in which, they felt, modest additional funding would exert “high leverage toward rapid progress.” Large facilities and well‐established research programs were explicitly excluded from consideration.

ISSN:0031-9228    

DOI:10.1063/1.2813696

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

The articles in this issue review the current status of neutron‐scattering facilities in the US and abroad, discuss in more depth some recent contributions of neutron scattering to fundamental studies of condensed matter—including biophysics—and suggest future scientific opportunities in these fields. The photo at right shows one of the sources that makes all these studies possible: the core of a reactor. Neutrons from fission reactions here are transported out of the reactor, collimated, and sent to scatter off a sample. This particular reactor is the High Flux Beam Reactor at Brookhaven National Laboratory.

ISSN:0031-9228    

DOI:10.1063/1.2813697

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

Since its discovery 50 years ago, the neutron has commanded public attention and respect. As an intermediary in nuclear fission, it is woven into the political fabric of modern life and seems destined to remain so. But the neutron plays many other, less prominent and controversial roles as well. It has, for example, technological applications in fields as diverse as logging oil wells, detecting art forgeries and doping electronic semiconductor materials, as D. Allan Bromley has reviewed in these pages.

ISSN:0031-9228    

DOI:10.1063/1.2813698

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

The other articles in this issue are concerned with the variety of science that goes on at reactor‐based neutron sources. Such sources, based on nuclear fission, have been available since 1942. It has been known since the 1930s that neutrons could be produced through spallation by sending a charged beam of accelerated protons or electrons into a target. However, it has only been in the last few years that the intensity of these spallation sources has been sufficient for the range of sophisticated experiments required to study the properties of condensed matter. Today there are a number of operating spallation neutron sources, and more with higher intensity are planned (see the table). In this article we want to explain the difference between doing experiments at steady‐state and at pulsed sources, illustrate what has been done with the modest sources now available, and speculate on some future experimental efforts. We do not have space to describe how a spallation source works: this information is presented in detail in earlier articles.

ISSN:0031-9228    

DOI:10.1063/1.881009

出版商:AIP    

年代:1985

数据来源: AIP

摘要:

Neutron scattering began in Europe, as in the United States, as a parasitic activity at nuclear reactors designed to operate as irradiation facilities or to test reactor technology. Through the 1950s and 1960s, research using neutron beams involved only a small number of scientists. Most of these scientists were from the reactor centers, although by the late 1960s the participation of university scientists was apparent, notably at the Munich and Harwell reactors. Nevertheless, the general picture remained one in which neutron‐scattering experiments, which were principally in solid‐state physics, were carried out by small groups of scientists somewhat isolated from the academic and industrial communities. Even when reactors designed to produce neutron beams became available, scientists working on neutron scattering remained relatively isolated.

ISSN:0031-9228    

DOI:10.1063/1.2813700

出版商:AIP    

年代:1985

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2813701

出版商:AIP    

年代:1985

数据来源: AIP