摘要:

An exciting branch of science, which started as recently as World War II and has a clearly discernible future of great promise, is that of the “transuranium elements”. These are the man‐made chemical elements with atomic numbers greater than that of the heaviest natural element, uranium, which has the atomic number 92.

ISSN:0031-9228    

DOI:10.1063/1.3058316

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

The conventional cyclotron, pioneered by Lawrence in the 1930's, is limited in energy by contradictory requirements for the magnetic field. To provide beam stability in the direction of the magnetic field, the field must decrease with radius. But to keep the beam in phase with a constant‐frequency dee voltage, the field must increase with radius as the particle mass increases. In a conventional machine, the first requirement is satisfied and phase loss of the beam has limited the energy of protons from this first‐generation cyclotron to about 15 MeV, but it has been pushed as high as 22 MeV by the Oak Ridge group.

ISSN:0031-9228    

DOI:10.1063/1.3058317

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

There are probably few areas of natural science outside of magnetohydrodynamics (MHD) and plasma physics where fundamental research touches so closely upon modern technological development. Since the classic work of Alfve´n, which received its impetus from astrophysics, the related problems of thermonuclear fusion, plasma propulsion, and MHD power generation have attracted some of the most able investigators in science and engineering. The effort already expended on these problems has been considerable and will without doubt be increased in the future. In recognition of the growing activity in these fields, the Basic Sciences Committee of the American Institute of Electrical Engineers organized the first meeting on the engineering aspects of magnetohydrodynamics at the University of Pennsylvania in 1960. Interest in the initial undertaking continued and a second conference was held in March 1961 at Philadelphia under the general chairmanship of Clifford Mannal (General Electric). With the advent of the third symposium, under the direction of N. W. Mather (Princeton), it is felt to be well on its way to becoming an annual gathering.

ISSN:0031-9228    

DOI:10.1063/1.3058318

出版商:AIP    

年代:1962

数据来源: AIP

摘要:

In 1905 the author became interested in selenium cells because of the unusual challenge to understanding which they presented. One of the bestknown selenium cells of that time was the Giltay Cell—a thin soapstone plate around which two parallel wires were wound, with selenium melted and crystallized between the wire electrodes. There were other types, but all had the same remarkable capacity to increase in electrical conductivity when exposed to light. By comparison, a metal, such as a blackened platinum foil, decreased in conductivity when exposed to light. Because of the light sensitivity, selenium cells had proved useful in several kinds of machines and instruments; for example, in the Optiphone and phonopticon, which could enable the blind to read the printed page.

ISSN:0031-9228    

DOI:10.1063/1.3058319

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3058320

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3058322

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3058323

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3058325

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3058326

出版商:AIP    

年代:1962

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3058328

出版商:AIP    

年代:1962

数据来源: AIP