摘要:

An unsupported‐area static or dynamic seal for sealing hydraulic pressures up to 50 kilobar in cylindrical pressure vessels is described.

ISSN:0034-6748    

DOI:10.1063/1.1134462

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Considerable differences in the current gain have been found in a channel electron multiplier when used as a detector of 100 keV N1+ions, depending on the point of impact at the channel entrance. These differences occur at high current gains which are usually considered near to saturation. In contrast to the current gain, the detection efficiency shows no significant variation with the point of impact, suggesting that at least one of the electrons from the primary interaction of the ion with the secondary surface is multiplied by the channel to provide a detectable pulse.

ISSN:0034-6748    

DOI:10.1063/1.1134463

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

We have measured the velocity distribution of a Na2supersonic beam by a time of flight method in which a chopped beam from an argon ion laser depopulates a single vibration–rotation level of the Na2ground electronic state, and a continuous laser beam further downstream is used to detect the arrival of the tagged molecules by observation of changes in the laser‐induced fluorescence.

ISSN:0034-6748    

DOI:10.1063/1.1134464

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A simple, computer automated method for measuring rotating frame relaxation times (T1&rgr;) for many line spectra on modified commercial NMR spectrometers is discussed. Sources of error and critical instrumental parameters are identified. Adjustment of the various parameters of the pulsed rf system is more critical than forT1but perhaps less so than forT2measurements.

ISSN:0034-6748    

DOI:10.1063/1.1134465

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Microchannel plates have been investigated for use as parallel‐bore collimators using a chopped electron beam. This note compares the collimation ability of plates with theory and gives transmission results. It is found that collimation ability approaches the ideal collimator when pulse duration does not allow charge buildup on tubule walls of the plate.

ISSN:0034-6748    

DOI:10.1063/1.1134466

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A high voltage pulse generator using stacks of silicon‐controlled rectifiers (SCRs) is described. Pulses of 2 kV are easily produced and applied to solutions for dichroic studies. The system is easily adapted for higher voltage pulses.

ISSN:0034-6748    

DOI:10.1063/1.1134467

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A new method of gain controlling of photomultipliers by means of a grid inserted between the photocathode and first dynode is derived. Photomultiplier characteristics of gain vs applied grid voltage for two types of Tesla Vu´vet phototubes are presented.

ISSN:0034-6748    

DOI:10.1063/1.1134468

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A clean opening system for a vacuum tube is discussed. This system presents the following advantages: before closure, the tube can be baked to temperatures of the order of 350 °C. Once sealed a high vacuum can be maintained inside, and the opening of the tube can be done in a high vacuum environment without degradation of the vacuum. This is achieved by cutting a fine membrane holding a cover. Different parts of the system have been tested successfully.

ISSN:0034-6748    

DOI:10.1063/1.1134469

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Electroplated lead contacts have been found to exhibit contact resistances lower than 10−9&OHgr;/mm2to tungsten below 7 K, and to withstand repeated thermal cycling between room temperature and liquid helium temperatures.

ISSN:0034-6748    

DOI:10.1063/1.1134470

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A push‐rod ac susceptibility apparatus which permits the measurement of ultrathin films of superconductors and ferromagnets as a function of temperature and magnetic field is described. Films prepared at 77 K can be mounted under liquid nitrogen and measured without warmup.

ISSN:0034-6748    

DOI:10.1063/1.1134471

出版商:AIP    

年代:1976

数据来源: AIP