摘要:

This paper describes an inexpensive versatile electronic circuit which will allow a conventional oscilloscope or anXYrecorder to be used as a transistor curve tracer. It can also be used to obtain Langmuir probe characteristics in plasma physics experiments.

ISSN:0034-6748    

DOI:10.1063/1.1139643

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This paper describes a 5‐ns rise‐time resistive voltage probe for use up to 150 kV. It is based on a wire‐counterwound design and uses low‐voltage arms incorporating fast switching diodes for oscilloscope protection. Much attention was paid to reducing inductance in the system through a compact layout, while still ensuring adequate dielectric insulation.

ISSN:0034-6748    

DOI:10.1063/1.1139644

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This paper describes a resistive voltage divider with subnanosecond rise time for use up to 50 kV using a ‘‘triple ladder’’ of metal film resistors. Its low‐voltage attenuators incorporate fast switching diodes for oscilloscope protection. The divider is used to measure fast transients generated by breakdown in SF6.

ISSN:0034-6748    

DOI:10.1063/1.1139645

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A simple, inherently linear technique for measuring changes in the separation of the mirrors of an optical cavity is reported. The capacitor made up of the reflective metallic coatings is part of a feedback loop which adjusts the frequency of an oscillator to be proportional to the mirror separation. A linearity of 0.2% full scale was achieved for separations up to 0.5 mm with a resolution of 10 nm.

ISSN:0034-6748    

DOI:10.1063/1.1139646

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A description is given of an optical probe, consisting of an optical microscope with modified internal illumination, a dual chopper with its two edges straddling the image plane, and a dual area sensor mounted behind the chopper. An analysis shows that the sensitivity of this proximity probe is essentially the same as that of the Simon probe, while its linearity is much better. Also, its construction is much simpler. A prototype has shown resolution of 0.02 &mgr;m and linearity errors of 0.5 &mgr;m (at 100‐&mgr;m range), respectively.

ISSN:0034-6748    

DOI:10.1063/1.1139647

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A technique is described which provides a linear pulse‐position modulated signal from an intrinsically analog remote optical sensor having a nonlinear response to the sensed parameter. The technique is applied to a differential absorption optical liquid level sensor. Sensor and system performance are presented.

ISSN:0034-6748    

DOI:10.1063/1.1139648

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We have developed a thin‐film Pt–Ir thermocouple which exhibits bulklike thermoelectric behavior up to 790 °C, the highest temperature observed with thin‐film pure‐element thermocouples. Using aQ‐switched Nd:YAG laser and a signal averaging oscilloscope, its thermal response time was measured to be 60 ns. The ease of implementation in electronic devices coupled with the reproducibility over a wide temperature range make this thin‐film thermocouple well suited for monitoring instantaneous temperatures during device processing.

ISSN:0034-6748    

DOI:10.1063/1.1139649

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A circuit is described which synchronizes the timebase of a transient waveform digitizer to a randomly occurring trigger signal synchronous with the experiment information which is to be digitized. The method described overcomes the triggering ambiguity of the recorder and, therefore, uncertainties in time origin of the recorded signals. Pretrigger information is still preserved accurately except for a±1 sample period uncertainty prior to the trigger event. The design is based around a 200‐MHz sample rate digitizer and uses a clock generator, which can be synchronized within one period to an external event. The same technique is applicable to slower clock rates and up to ∼500 MHz.

ISSN:0034-6748    

DOI:10.1063/1.1139595

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We have designed a3He cryostat which can be inserted into a storage Dewar. This cryostat requires no external gas‐handling system and has the advantages of extremely low (and recoverable) helium consumption, fast cooldown and warm‐up times, excellent temperature range and stability, and low vibrational and electrical noise. The freedom from an external gas‐handling system allows for portability and flexibility in its uses. Design and construction of the cryostat are presented, and operation and performance are discussed in some detail. To demonstrate performance of the cryostat, we present thermal boundary resistance measurements between 0.4 and 170 K for a solid–solid interface (Rh:Fe/sapphire).

ISSN:0034-6748    

DOI:10.1063/1.1139596

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The effect of residual series inductance on dielectric measurements with transmission line resonators is analyzed in detail. The analysis is useful for determining when errors due to such inductance are important, and outlines the calibration approach which minimizes inductance errors. The results also suggest a method for resonator calibration with varactor diodes.

ISSN:0034-6748    

DOI:10.1063/1.1139597

出版商:AIP    

年代:1987

数据来源: AIP