摘要:

An electronic interface coupler has been designed which extracts data from a digital transient recorder and prepares the signal for recording by a magnetic tape unit which is compatible with a laboratory computer. System operation, circuitry, and software are discussed.

ISSN:0034-6748    

DOI:10.1063/1.1686208

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

S/N ratios for ion and metastable detection of neutral molecular beams which utilize time integrated measurements of an electron multiplier output are discussed. It is shown that the excitation probability is considerably less than the ionization probability for most molecules causing S/N improvements with metastable detection to be less than previously expected. An additional decrease results from the low electron yield of the metastable molecule compared to the ion at the electron multiplier surface.

ISSN:0034-6748    

DOI:10.1063/1.1686209

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

Selected components, construction techniques, and a simple circuit are described for use in building constant current supplies which are dialable throughout the 100 &mgr;A—100 mA range, with 0.01% resolution and long term stability approaching 0.001%.

ISSN:0034-6748    

DOI:10.1063/1.1686210

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A description is given of a simple and cheap air admittance valve for automatic air inlet into turbomolecular pumped UHV system upon (controlled or uncontrolled) power cutoff. The valve is operated by a mechanical timer switch which can be adjusted such that dry air admittance starts just before the turbo pump has finished its pumping action completely. Thus, contamination of the UHV compartment by oil vapor from the turbo pump and other active gases from the force vacuum is prevented and quick reobtainment of vacuum in the 10−9Torr region after system restart becomes an easy matter.

ISSN:0034-6748    

DOI:10.1063/1.1686211

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A vacuum oven inside a microwave cavity for high temperature experiments is described. Temperatures up to 800°C can be easily obtained while the cavity stays at room temperature.

ISSN:0034-6748    

DOI:10.1063/1.1686212

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

In order to obtain accurate thermal resistance data for contacts under high loads (i.e.,P/M> 2×10−3) it is not always necessary to employ a high vacuum for transverse thermal insulation, or a guard‐heater arrangement.

ISSN:0034-6748    

DOI:10.1063/1.1686213

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

This Note describes a thermocouple network for measuring an average temperature of a convex surface. A version for a cylindrical surface is illustrated. The device combines advantages of a resistance thermometer and of a simple thermocouple. It is relatively easy to mount; it provides a distributed temperature measurement; and it is operated as an ordinary thermocouple.

ISSN:0034-6748    

DOI:10.1063/1.1686214

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A relatively simple and rapid method for preparing high‐quality electron microscope disk specimens from electrically conductive and nonconductive brittle bulk materials is described. The technique utilizes a model 2–334 Raytheon ultrasonic impact grinder to generate and transmit high frequency vibrational energy through a tube‐shaped tool tip to an abrasive‐water slurry circulated over the bulk material. Machining is accomplished by the abrasive particles resonating and impacting the bulk material in a vertical plane below the tool tip. The net effect produces a microscopic grinding action on the workpiece that parallels the contour of the end of the tool tip.

ISSN:0034-6748    

DOI:10.1063/1.1686215

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A method is proposed for resolving the convolution integral of fluorescence pulse by means of an electric circuit to deduce the lifetime since it is concluded from the theoretical results that the behavior of fluorescence is analogous to the distortion of an electric pulse after passing through a circuit.

ISSN:0034-6748    

DOI:10.1063/1.1686216

出版商:AIP    

年代:1973

数据来源: AIP

摘要:

A high resistivity coating develops at the surface of a special glass when heated in a hydrogen atmosphere at about 470°C. The glass contains 85% heavy lead oxide glass and 15% Bi2O3, and is ideally suited to prepare channel electron multipliers.

ISSN:0034-6748    

DOI:10.1063/1.1686217

出版商:AIP    

年代:1973

数据来源: AIP