ISSN:0031-9228    

DOI:10.1063/1.3070953

出版商:AIP    

年代:1972

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3070954

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Following are corrections I have received to my review of Pimenov's book (April 1972):Einstein did not find differential geometry “ready for him.” He had reinvented half of it before hearing of its existence.Signals may propagate in Pimenov's semi‐Riemannian spaces with arbitrarily high velocity, never “instantaneously.”The index for which “the work pleads” was present in the original Russian.Pimenov's imprisonment is not the result of any publication but merely of preliminaries to publication.

ISSN:0031-9228    

DOI:10.1063/1.3043318

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The Brookhaven solar‐neutrino experiment, after five years of running, is in even worse disagreement with theoretical expectations than it was earlier. While the theoretical value has tended to rise slightly, the experimental limit has dropped and is consistent with zero.

ISSN:0031-9228    

DOI:10.1063/1.3070956

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The intrinsic interest in an empty box is limited, however difficult the task of evacuating it may be. It is the new vistas in science and technology opened by the ability routinely to produce ultra‐high vacua as a controlled environment that excite our interest. The challenges of generating and measuring such vacua will be described in the following articles of this issue ofPHYSICS TODAY. We devote our discussion to recent developments in the study of surface phenomena, an area of science that has been both a beneficiary of and contributor to advances in vacuum technology.

ISSN:0031-9228    

DOI:10.1063/1.3070957

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The need for a vacuum environment has been encountered by more and more fields over the years. In high‐energy accelerators, extraneous molecules would attenuate the beam of particles being accelerated. In mass spectrometers, atmospheric gases would mask the sample being analyzed. In thin‐film production, impurities would affect the electrical properties of the film being deposited. Similar considerations arise in the fields of space simulation, surface physics, thermonuclear research, pollution detection and control, analytical instrumentation and many others.

ISSN:0031-9228    

DOI:10.1063/1.3070958

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Over the past ten or fifteen years, modifications of the diffusion pump have doubled its pumping speed reduced backstreaming of pump fluids by four or five orders of magnitude. These improvements result from redesign of some basic pump features and from development of new pump fluids with lower vapor pressures.

ISSN:0031-9228    

DOI:10.1063/1.3070959

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The basis for essentially all gauges used for total or partial‐pressure measurement in ultrahigh vacuum is the ionization produced by electrons traversing the space between two electrodes. The ratio of ion current to ionizing current is measured and assumed to be proportional to the gas density or pressure. This principle has been used for over fifty years, spurred and nurtured by the vacuum‐tube industry, so it was natural that early gauges resembled simple triode receiving tubes (see figure 1 on the facing page).

ISSN:0031-9228    

DOI:10.1063/1.3070960

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The primary function of very high and ultrahigh vacuum equipment is to provide an environment that is superbly nonreactive: so neutral that molecular, electron and other submolecular beams can travel uninhibited; that chemically reactive metals can be heated to any temperature and be improved rather than degraded; that physiochemical reactions can be precisely controlled without contamination problems.

ISSN:0031-9228    

DOI:10.1063/1.3070961

出版商:AIP    

年代:1972

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.3070962

出版商:AIP    

年代:1972

数据来源: AIP